Windows Media Encoder

Transcription

1 Page 1 of 100 Windows Media Encoder Microsoft Windows Media Encoder 9 Series is a powerful production tool for converting both live and prerecorded audio and video into Windows Media files or streams. The following sections introduce conceptual information about the encoding process and provide steps for using Windows Media Encoder. Getting started. Explains how you can set up an encoding session in a few short steps by using quick starts or the New Session Wizard. Also describes changes to Windows Media Encoder, describes the system requirements, and provides information about the various panels that make up the user interface. Concepts. Provides general information about working with the encoder. Configuring sources. Provides information about the input sources supported by the encoder, including files, devices, screens, and script commands. Customizing a session. Describes how to configure a new encoding session or customize an existing session to meet your needs. Output options. Describes the output options available to you when encoding: encoding to a file or broadcasting a live event (by using either push or pull distribution). System configuration options. Describes system configuration options, including security for the encoding computer, running multiple instances of the encoder on a computer, batch encoding, and the steps you can take to achieve optimal system performance. Frequently asked questions and troubleshooting. Provides a link to the Microsoft Web site where you can find suggestions for resolving issues that might arise when using the encoder. Technical support options. Lists phone numbers and Web sites that you can use if you require additional support. Accessibility for people with disabilities. Provides information about features, products, and services that make Windows Media Encoder more accessible for people with disabilities. Glossary. Provides definitions and terms related to the encoder. Getting started This section includes information about how you can set up an encoding session in a few short steps by using quick starts or the New Session Wizard. It also includes information about what is new in this version of Windows Media Encoder, feature requirements, hardware and software requirements, and describes the various panels that make up the encoder interface. Windows Media Encoder Encoding with quick starts or the New Session Wizard

2 Page 2 of 100 What's new Feature requirements Hardware and software requirements About encoder views About the encoder utilities Documentation conventions Encoding with quick starts or the New Session Wizard Before encoding content, you must set up an encoding session. The easiest way to do so is to use quick starts or the New Session Wizard. Quick starts are session files that are included with Windows Media Encoder. They are designed to address common encoding scenarios and already include most of the settings you need to begin encoding without delay. All you need to do is provide specifics about your content, such as file names or server names. You can also use the New Session Wizard, which walks you through the steps necessary to set up four of the most common encoding scenarios. The quick starts and wizard are available from the New Session dialog box (if enabled) that is displayed when you first open the encoder or from the main encoder window by clicking New Session on the toolbar. After you set up your encoding session, you are ready to encode content. If you plan to run the same session again, you can save the settings to a session file and then use the session at a later date. Session files are saved with a.wme extension. Getting started Using quick starts to encode Using the New Session Wizard to encode About sessions To open an existing session To save a session Using quick starts to encode

3 Page 3 of 100 Quick starts are session files that are included with Windows Media Encoder. They are designed to address common encoding scenarios and already include most of the settings you need to begin encoding without delay. All you need to provide is specifics about your content, such as file names or server names. The available quick starts include: Capture live content for local playback. Captures live content from audio and video devices and encodes it to a file. You can distribute the content so users can download and play it locally. Capture live content for streaming. Captures live content from audio and video devices and encodes it to a Windows Media file. Convert film content to video. Converts file-based content that originated on film to Windows Media Format so users can download and play it locally. Broadcast company meeting. Pushes a stream to a publishing point on a server running Microsoft Windows Media Services. If you have a session that you want to use frequently, you can add it to the list of quick starts. Note To launch the quick starts, on the toolbar, click New Session, click the Quick Starts tab, and then click a quick start. Encoding with quick starts or the New Session Wizard To create a custom quick start About CBR or VBR encoding Using the New Session Wizard to encode The New Session Wizard walks you through the steps necessary to set up four of the most common encoding scenarios. The four common encoding scenarios are: Broadcast a live event. Captures audio or video from devices installed on your computer and then broadcast the content live, either by pushing the stream to a server running Microsoft Windows Media Services or by enabling Windows Media servers and players to pull the stream directly from the encoder. Capture audio or video. Captures audio or video from devices installed on your computer and then convert the captured content to a Windows Media file for later distribution. Convert file. Converts an audio or video file to Windows Media Format for later distribution. Capture screen. Captures screen images, including mouse pointer movements, on the computer. You can capture the entire screen, a region of the screen, or a specific window.

4 Page 4 of 100 To change session properties, you can either run the New Session Wizard again or use the Properties panel to edit your settings. If you plan to reuse the session, save your settings in a session file. Note To open the New Session Wizard, on the toolbar, click New Session, and then click one of the four wizards. You can use Custom session to set up a custom encoding session. Encoding with quick starts or the New Session Wizard To save a session What's new Windows Media Encoder 9 Series includes enhancements that are both powerful and easy to use. This section summarizes the changes to the encoder for this release. Targeting various encoding scenarios has been made easier with the addition of new destinations. In addition, four quick starts are available that help you begin encoding without delay. Each quick start is designed to address a common encoding scenario. New codecs have improved the quality of encoded audio and video content. Support for dragging source files and session files to the encoder window makes it easy to begin encoding quickly. New constant-bit-rate (CBR) and variable-bit-rate (VBR) encoding modes enable you to finetune settings depending on the playback scenario you are targeting. A device control feature enables you to run devices directly from the encoder. (The device must be connected to an IEEE 1394 digital video port, or you can use a video tape recorder (VTR) that supports the Sony RS422 protocol and that is connected through a COM port.) You can also use the built-in edit decision list (EDL) to arrange and encode clips in any order. Multichannel audio encoding is available through the Windows Media Audio 9 Professional and Windows Media Audio 9 Lossless codecs. Digital rights management (DRM) is available for you to protect encoded content. New push distribution feature helps you to initiate the connection with a Windows Media server from the encoder. Language support lets you specify the language of your content. Four utilities are included to provide additional features such as creating custom profiles, splitting and combining streams in different files, and indexing files after encoding. Temporary storage of content to hard disk helps you to ensure the quality of encoded content. Support of transform plug-ins enables developers to write plug-ins that modify audio and video content, which you can use to add special effects during encoding. Support for sourcing from additional file formats has been implemented. Support for nonsquare pixel output helps you to encode letterboxed content while maintaining the aspect ratio of the source video. Frame-level seeking can be implemented by creating or preserving time codes for some sources.

5 Page 5 of 100 Multiple bit rate (MBR) content now supports multiple audio formats and video resolutions. Support for the Microsoft Windows XP Plug and Play feature enables devices to be automatically detected by the encoder when running. In addition, the encoder is automatically launched when a new device is connected to the computer. Getting started Using quick starts to encode Understanding codecs About CBR or VBR encoding Sourcing from devices Sourcing from multichannel audio files Using digital rights management to protect content Broadcasting content live About the encoder utilities Feature requirements The following table provides information about the Windows Media Encoder features that have specific Microsoft Windows Media Player, operating system, or codec requirements. Feature Windows Media Player Operating systems Codecs Interlaced output video /Windows XP 9 Series Nonsquare pixel X output Multiple-resolution X MBR content MBR audio X DRM support X X X X Microsoft Windows XP Multichannel audio X Microsoft Windows XP Windows Media Video 9 Windows Media Audio 9 Professional or Windows Media Audio 9 Lossless High-resolution audio X Microsoft Windows Media

6 Page 6 of 100 (24-bit, 96 khz) 1 Windows XP Audio 9 Professional Dynamic range control CBR encoding (oneor two-pass) 1 Earlier players or operating systems will render 16-bit, 48-kHz content Note that content encoded with the Windows Media Audio and Video 9 Series codecs (except for the Windows Media Audio 9 codec) is not supported in Windows Media Player version 6.4. For Windows Media Player version 7.1 and Windows Media Player for Windows XP, content encoded with any of the codecs requires users to download the codec before playback. Content encoded using VBR encoding with the Windows Media Audio 9 codec may have glitches or silence during playback in Windows Media Player version 6.4. For Windows Media Player version 7.1 and Windows Media Player for Windows XP, content encoded with the Windows Media Audio 9 codec does not require a user to download the codec. The following table lists the supported encoding methods for the codecs that are included with the encoder. X Microsoft Windows XP Windows Media Audio 9 Professional X X X See the following table Quality-based VBR X X See the following table Bit rate-based VBR X X See the following table Peak bit rate-based VBR Codec Windows Media Audio 9 Professional Windows Media Audio 9 Lossless Windows Media Audio 9 One-pass CBR X X See the following table Two-pass CBR Quality-based VBR Bit ratebased VBR Yes Yes Yes Yes Yes No No Yes No No Yes Yes Yes 1 Yes 1 Yes 1 Windows Media Yes No No No No Audio 9 Voice Windows Media Yes Yes Yes Yes Yes Video 9 Windows Media Yes Yes Yes Yes Yes Video 8.1 Windows Media Yes Yes Yes Yes Yes Video 7 Windows Media Yes No Yes No No Peak bit ratebased VBR

7 Page 7 of 100 Video 9 Screen 1 Some glitches or silence may occur during playback in Windows Media Player version 6.4. Getting started About CBR or VBR encoding Hardware and software requirements You can find up-to-date information about hardware and software requirements at several Web sites: For information about system requirements, see the system requirements page at the Microsoft Web site. For a list of supported audio and video capture cards, see the hardware providers page at the Microsoft Web site. For a list of supported portable devices, see the portable devices page at the Microsoft Web site. Getting started About encoder views The main window of Windows Media Encoder has numerous panels that provide information about the current session. The panels that are displayed when you encode depend on the type of content being encoded, the number of sources set up for the current session, and your personal preferences. You can display additional panels or hide the ones that are displayed. Any changes you make to the window are saved between sessions. Properties panel. Includes properties that you can use to adjust the settings related to the current session or to set up a custom session. Video panel. Displays the content you are encoding. Depending on the type of content, you can customize the window to show just the pre-encoded content, the encoded content, or both.

8 Page 8 of 100 In some instances, the source content or encoded output is not displayed during encoding. Sources panel. Lists each source in the current session. You can switch between sources while encoding by clicking the appropriate source button. Audio panel. Contains controls for monitoring and adjusting the volume of the audio stream you are encoding. Device panel. Appears when you have a device connected to your computer either through an IEEE 1394 port or a COM port using a video tape recorder (VTR) that supports the Sony RS422 protocol. You can control the play, pause, stop, fast-forward, rewind, and eject functions of your device in this panel. You can also create an edit decision list (EDL) to automatically encode specific time segments of your content on one or more video tapes. Monitor panel. Contains status information about the session. Script panel. Appears if you enabled scripts as a source type when you set up the current session. You can insert a script command into the stream during encoding from this panel. To display or hide a panel, on the View menu, click the panel you want to display or hide. Getting started About the encoder utilities Four utilities are included with Windows Media Encoder: Windows Media Profile Editor. Use to create custom profiles for use in encoding sessions. Windows Media File Editor. Formerly called the Windows Media ASF Indexer, you can use this tool to edit a Windows Media file. For example, you can trim the start and end points of the file; add markers, and script commands; control the dynamic range of audio content; and, for multichannel audio files, control how the channels are folded down for stereo playback. Windows Media Stream Editor. You can use this tool to split or combine streams in existing Windows Media files to create a file. For example, you can split an MBR file into multiple single-bit-rate files. Or, you can create multiple files, each with the same video stream but a different audio stream (for example, to create a single file with multiple languages). Windows Media Encoding Script. Formerly called the Windows Media Encoding Utility, you can use this command-line utility (Wmcmd.vbs) to encode and broadcast content. This utility is installed in the same location as the encoder, which is C:\Program Files\Windows Media Components\Encoder by default. Getting started To access an encoder utility

9 Page 9 of 100 To access an encoder utility 1. Click Start, point to Programs, point to Windows Media, and then point to Utilities. 2. Click the utility you want to use. Note You can access help for the Windows Media Encoding Script from the same location. About the encoder utilities Documentation conventions The following conventions are used in this Help system. This convention Bold Italics Code Indicates Text that appears in the user interface or should be typed into the user interface exactly as shown. Placeholder text you should replace with text appropriate to your environment. Sample code you should replace with code appropriate to your environment. Getting started

10 Page 10 of 100 Concepts This section provides general information about working with Windows Media Encoder 9 Series. Windows Media Encoder Understanding codecs About sessions Comparing Windows Media servers and Web servers About CBR or VBR encoding About one- or two-pass encoding Understanding codecs Uncompressed audio and video content can consume a lot of bandwidth when streaming or create large files. By compressing the content, it can be broadcast over common Internet bandwidths or saved to a Windows Media file of a reasonable size. You can compress content by applying compression algorithms to the data, taking into account the desired output quality and available bandwidth. Before the content is played, it is decompressed by using decompression algorithms. These compression and decompression algorithms are called codecs. The following table provides more detailed information about the codecs available in Windows Media Encoder. Codec Windows Media Audio 9 Professional Windows Media Audio 9 Lossless Windows Media Audio 9 Windows Media Audio 9 Voice Windows Media Video 9 Description Provides a full surround sound experience and dynamic range control. Intelligently folds down multichannel audio to 2 (stereo) or 1 (mono), depending on the speaker configuration of the playback device. Intended for data rates of 128 to 768 Kbps. Provides lossless encoding of audio content. Supports multichannel audio encoding and dynamic range control. Provides a 20 percent improvement in compression over the Windows Media Audio 8 codec. Supports VBR audio encoding. Offers superior quality for audio content with a voice emphasis. Provides for mixed-mode encoding of voice and music. Intended for playback at bit rates at 20 Kbps or lower. Creates high-quality video for streaming, download-and-play, and physical format delivery scenarios. Provides a 15 to 50 percent improvement in compression over the Windows Media Video 8.1 codec, with the more significant improvement occurring at higher bit rates. Enables playback of interlaced content on televisions and set-top boxes.

11 Page 11 of 100 Windows Media Video 8.1 Windows Media Video 7 Windows Media Video 9 Screen Supports a wide variety of network bandwidths. Deinterlaces interlaced content before encoding. Enables users of Windows Media Player 7 to view encoded video content without first having to download the latest codecs. Best choice when the encoding computer cannot support the performance requirements of the newer Windows Media Video codecs. Provides improved handling of shaded images, screen motion, and scrolling for screen captures. Supports one-pass CBR and VBR encoding with no frame dropping. This codec is fully optimized for both streaming and download-and-play scenarios. Note In some instances, the Sipro Labs ACELP codec appears in the list of codecs. For example, if you import a profile that was created by using Windows Media Encoder version 7.1. If this occurs, it is recommended that you use the Windows Media Audio 9 Voice codec instead. Concepts About sessions Before you can encode, you must set up an encoding session. As part of setting up the session, you must do the following: Specify the source of your audio or video content. You can source from devices, files, or both devices and files. You can also capture screens directly from your desktop. Choose the output option. Select whether to broadcast the content or encode it to a file. If you broadcast the content, you can push the stream to a Windows Media server, and you can enable Windows Media servers and players to pull the stream from the encoder. You can also choose to archive a copy of the broadcast for later use. In addition, you should check compression and quality settings before you encode. Default settings are applied, but it may be necessary to adjust the settings to meet your needs. For example, if you are planning to distribute your content for download-and-play on a computer, you may want to use bit rate-based VBR encoding and set the video and audio quality level to the higher bit rate. After you have identified the source of your content and specified the output, you have a number of options for customizing a session. For example, you can optimize audio and video to improve the quality of the encoded content. After configuring the session to meet your needs, you can start encoding. If you want to run the same

12 Page 12 of 100 session again, you can save the session to a session file either before or after you encode. Note It is not necessary to create a session each time you encode. The encoder includes quick starts and the New Session Wizard, which address common encoding scenarios. Concepts Configuring sources Output options Customizing a session Encoding with quick starts or the New Session Wizard To save a session Comparing Windows Media servers and Web servers You can deliver content from a server running Windows Media Services or from a Web server to a player. The server and player can be either on the Internet or an intranet, and they can be separated by a firewall. Although a Windows Media server is designed specifically for streaming Windows Media-based content, a standard Web server is not. If you decide to use a Web server, you should be aware of the differences in the way the content is delivered, which can affect the quality of the playback. Windows Media servers A Windows Media server meters the delivery of packets according to feedback information it receives while sending a stream to a player. When a player receives packets in this way, the presentation is much more likely to be smooth. Because bandwidth use is controlled, more users can connect concurrently to your site and receive streams that are free of interruptions. If you plan to deliver your content as a unicast stream from a Windows Media server, you can encode a multiple-bit-rate (MBR) stream. This provides users with better quality content during times of network congestion. When MBR content is received by a player, only the bit rate that is the most appropriate for network bandwidth conditions is streamed. The process of selecting the appropriate stream is handled by the Windows Media server and the player and is invisible to the user. When streaming single-bit-rate streams or files, a Windows Media server is designed to handle network congestion smoothly. If congestion occurs during the broadcast, the stream is "thinned", which means that the frame rate is reduced. If this is insufficient, the video portion of the stream is frozen and only the audio portion is streamed.

13 Page 13 of 100 Web servers A Web server is designed to download as much data as it can, as quickly as possible. This is the preferred method for sending packets containing static images, text, and Web page script, but it is not the best method for sending packets containing streaming media. Streaming media should be delivered in real time, not in large bursts, and the player should receive packets just ahead of rendering them. Web servers do not support MBR streams. When a file streams from a Web server, the quality of the delivery is not monitored and no adjustment to the bit rate can be made. Web servers cannot use the preferred delivery protocol, User Datagram Protocol (UDP), so the delivery of a stream is more likely to be interrupted by periods of silence while the player buffers data. In addition, Web servers do not support live broadcasts and multicast streams. Note Windows Media Services 9 Series in Windows.NET Server 2003 includes several features, called Fast Streaming, which can combine some of the advantages of downloading and streaming. For more information about Fast Streaming, see Windows Media Services Help. Concepts Output options About CBR or VBR encoding Using Windows Media Encoder, you can encode audio and video content at either a constant bit rate (CBR) or a variable bit rate (VBR). CBR encoding CBR encoding is designed to work most effectively in a streaming scenario. With CBR encoding, the bit rate remains fairly constant and close to the target bit rate over the course of the stream, within a small window of time set by the buffer size. The disadvantage of CBR encoding is that the quality of the encoded content is not constant. Because some pieces of content are more difficult to compress than others, some parts of a CBR stream are of lower quality than others. In addition, CBR encoding results in inconsistent quality from one stream to the next. In general, quality variations are more pronounced at lower bit rates. VBR encoding Use VBR encoding when you plan to distribute the content for downloading and playing either locally or on a device that has a constrained reading speed, such as a CD or DVD player. (You can also use the peak VBR encoding mode when you plan to stream the content.) VBR encoding is most

14 Page 14 of 100 advantageous when encoding content that is a mix of simple and complex data, for example, a video that switches between slow and fast motion. With VBR encoding, fewer bits are automatically allocated to less complex portions of the content, leaving enough bits available to produce good quality for more complicated ones. This means that content that has consistent complexity (for example, a "talking head" news story) would not benefit from VBR encoding. When used on mixed content, VBR encoding produces a much better encoded output given the same file size when compared to CBR encoding. In some cases, you can end up with a VBR-encoded file that has the same quality as a CBR-encoded file in half the file size. Encoding mode options With CBR encoding, you can use one- or two-pass encoding. You have three VBR encoding options: quality-based VBR (one-pass), bit rate-based (two-pass), and peak bit rate-based VBR (two-pass). Not all codecs support two-pass CBR encoding or VBR encoding. Concepts Using CBR encoding Using VBR encoding About one- or two-pass encoding Feature requirements About one- or two-pass encoding With Windows Media Encoder, you can do one- or two-pass encoding, either with CBR or VBR encoding. (The quality-based VBR encoding mode is one-pass; the bit rate-based and peak bit ratebased VBR encoding modes are two-pass.) With one-pass encoding, the content passes through the encoder once, and compression is applied as the content is encountered. With two-pass encoding, the content is analyzed during the first pass, and then encoded in the second pass based on the data gathered in the first pass. Two-pass encoding can result in better quality content because the encoder takes its time to find the optimal combination of bit rate, frame rate, buffer size, and image quality based on the scene composition. However, twopass encoding takes longer because the encoder goes through all of the content twice. Two-pass encoding is not available in the following situations: The stream is broadcast There are multiple sources in a session The source is set to loop Script commands are included in the stream Source content is from devices, unless you have enabled device control The source file has a.bmp file name extension

15 Page 15 of 100 In addition, two-pass encoding is only available with certain codecs. For a list of the codecs that support two-pass encoding, see Feature requirements. Note If you are using two-pass encoding, you will not see the output video in the encoder during the first pass. Concepts About CBR or VBR encoding Enabling device control Configuring sources Using Windows Media Encoder, you can encode live content in real time, stored content, or capture screens. Real-time sources of content include anything that you can plug into your audio or video card, including a CD player, microphone, VCR, video camera, video player, or television. Stored sources are audio or video files. You can also capture screens directly from your desktop, and insert script commands while encoding. Keep in mind that the higher the quality of the source content, the higher the quality of the output content. This means that you should start with the highest quality source file or, if sourcing from devices, set your device to capture the highest quality possible. When configuring a source, you first identify the source types (audio, video, or script) that make up the source. A source must consist of at least one audio or video source type. You can add an unlimited number of sources to an encoding session, either before or after encoding begins, but each subsequent source is based on the combination of source types you created in the session. For example, if your first source contained only audio, then all subsequent sources in the session are based on audio only. For multisource sessions, it is recommended that you configure your first source to use all three source types. If additional sources do not use a source type, you can encode a blank stream for that source type. Windows Media Encoder Sourcing from a file Sourcing from multichannel audio files Sourcing from devices Capturing screens Inserting script commands Using multiple sources in a session

16 Page 16 of 100 Sourcing from a file Using Windows Media Encoder, you can source from files with.wma,.wmv,.asf,.avi,.wav,.mpg,.mp3,.bmp, and.jpg file name extensions. (Sourcing from a file with a.mpg file name extension requires a compatible MPEG-2 decoder on the encoding computer.) If you are encoding a Windows Media file, any header attributes associated with the file (for example, markers, script commands, and so on) are lost in the process. You can use Windows Media File Editor to add the following attributes back to the file: title, author, copyright, and description. When sourcing from a file, you can trim the start and end times of the file to ensure that you encode only the part of the file you want. For more information about obtaining an MPEG-2 decoder, see the Microsoft Web site. Note Files that contain images with odd-sized dimensions are not supported. For example, an image that is 300 x 321 pixels is not supported, but an image that is 300 x 320 pixels is supported. Configuring sources To source from a file To source from a file 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click File. -or- Click Both device and file to source audio and video from two different files. 3. To locate the source file click Browse. 4. If you want to trim the start or end of the file, click Mark In/Out. Only the remaining portion of the file is encoded. 5. If you want to encode only the audio or only the video portion of a file, clear either the Video

17 Page 17 of 100 or Audio check box. Note You can also drag a source file to the encoder. Sourcing from a file Sourcing from multichannel audio files Using Windows Media Encoder, you can encode multichannel audio, which means you can encode audio for a surround sound playback in six (5.1 audio) or eight (7.1 audio) channels. The format is specifically designed for CD, DVD, high definition television, and digital cinema audio programs. Your content source must be one of the following: A single 6-channel or 8-channel file that has a WAVE_FORMAT_EXTENSIBLE format. For more information, see the Microsoft Web site. If you are sourcing from an 8- channel file, it is recommended that the sampling rate and bits per sample of the source file and the encoded content match. Six mono channel.wav files. To create the files, use an audio editing program to fold down your audio to six files, one for each channel. When you set up your source in the encoder, you specify which channel each file is associated with. Each.wav file cannot exceed 2 gigabytes (GB) in size. This option is not available with 7.1 audio. An existing multichannel Windows Media Audio file. Use an existing file to encode the file at a different bit rate. It is not possible to encode an existing multichannel Windows Media Audio file if the encoder is on a computer running Windows You must use either the Windows Media Audio 9 Professional codec or the Windows Media Audio 9 Lossless codec and an audio format that supports multichannel encoding when encoding multichannel content. In addition, the user playing your content must have Microsoft Windows XP and a player that is based on the Windows Media Format 9 Series Software Development Kit (SDK). Otherwise, the audio will be folded down automatically to two channels for stereo speakers. The encoder automatically folds the channels down to two for playback with stereo speakers. If you are encoding 5.1 audio, you can control the fold-down distribution between the surround, center, and subwoofer channels on the Processing tab of the Properties panel. If you encoded the content to a file, you can also use Windows Media File Editor to control the fold-down distribution in the output file. Configuring sources To source from multichannel audio files

18 Page 18 of 100 To source from a file To source from multichannel audio files 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. In Audio, click Multichannel WAV Source, and then click Configure. 4. For each channel, enter the source.wav file. 5. Click the Compression tab. 6. In Destination, click either File download, Hardware devices, Windows Media server, or Web server, depending on the playback scenario. 7. In Audio, click Multichannel audio. 8. Click Edit, and then click the bit rate tab. 9. In Audio format, click the 5.1 or 7.1 audio format you want to use. Note The encoder automatically folds the channels down to two for playback with stereo speakers. If you are encoding 5.1 audio, you can modify the default fold-down distribution on the Processing tab. Sourcing from multichannel audio files Sourcing from devices When you source content from devices, you must first choose the audio or video devices you want to use. After choosing the devices, you can set their properties directly from the encoder. The properties for some devices, such as audio and video cards, are global and apply not only to all sources in your encoding session but to all programs on your computer. (For example, brightness, contrast, capture dimensions, and audio mixer settings.) You can use devices and capture cards only once in a session. For example, if you create two sources one source is a live event in which a speaker is introducing a new video, and the second source is the video you need a separate card and device for each source. Some devices can be controlled directly from the encoder. If you have enabled device control, you

19 Page 19 of 100 can set up an edit decision list (EDL) in which you identify the portions of tape that you want to encode. You can configure audio and video device properties by using the New Session Wizard, the Properties panel, or the Configure Devices command on the Tools menu. Devices must already be installed on your computer to configure them in the encoder. You cannot use the encoder to add or remove hardware; use Control Panel instead. If you have installed a supported TV tuner card, you can change the TV channels by using the encoder. Configuring sources Enabling device control Setting up an EDL To source from devices To change the TV channel being encoded To source from devices 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. In Video and Audio, click the devices you want to source from. Sourcing from devices To change the TV channel being encoded 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. In Video, click the TV tuner card you want to source from. 4. Click Configure. 5. In Channel, type the channel you want to encode. 6. In Inputs, select the tuner option, and then click OK. 7. In Audio, click the capture card that you have configured to use with the TV tuner card.

20 Page 20 of 100 Sourcing from devices Enabling device control By using the device control feature, you can run certain types of devices directly from the encoder. Device control enables you to control the play, pause, stop, fast-forward, rewind, and eject functions of your device from the encoder. To enable device control, the device must be connected to an IEEE 1394 digital video port, or you can use a video tape recorder (VTR) that supports the Sony RS422 protocol and that is connected through a COM port. You can also use the built-in edit decision list (EDL) of the device control feature to arrange and encode your clips in any order. When you have enabled device control, you can use two-pass encoding if you have done the following: Chosen to encode to a file Chosen to store content temporarily Set up an EDL for the content Note If a device you are using in the session does not appear in the Configure Devices dialog box, close the dialog box, click Apply, and then open the dialog box again. Sourcing from devices Setting up an EDL To store captured content temporarily To enable device control To enable device control 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. In Video and Audio, click the device you want to source from.

21 Page 21 of 100 If the device does not appear in the list, check that the device is turned on. It may be necessary to quit and restart the encoder after turning the device on. 4. Click Apply. 5. On the Device panel, click Setup. 6. In the list, select the device or COM port through which the device is connected, and then click OK. 7. Use the controls on the panel to control the device. Note To control a digital device from the encoder, the device must be set to VTR mode; VTRs must be set to TC mode. Enabling device control Setting up an EDL If you have enabled device control, you can specify, by time stamp, the exact place within your audio or video content that you want encoding to begin and end. To do so, you must create an edit decision list (EDL), which identifies the portions of tape you want to encode. It is not recommended that you use an EDL for a broadcast because the encoder requires extra time to seek to the EDL points during encoding. During a broadcast, this could cause excessive buffering on a player. You can add as many EDL entries as you want in any order not necessarily in the order in which they occur in the tape. You can also set up an EDL that sources from multiple tapes. During the encoding session, the encoder will prompt you when it is time to change the tape. You should use a prestriped tape when setting up an EDL. To prestripe a tape, you can record the tape continuously from beginning to end when you first buy the tape. This ensures that the time code in the tape is continuous. If the tape is not prestriped, then the device will generate a new time code every time you set up an EDL for the device. Sourcing from devices Enabling device control To set up an EDL

22 Page 22 of 100 To set up an EDL 1. Set up a device control session that encodes to a file. 2. On the View menu, click Monitor panel, and then click the EDL tab. 3. Click Edit EDL. 4. In the Device area, click Play to begin playing the tape. You can also begin playing the tape at a specific point by using other playback controls, such as the Seek to and Fast forward buttons. 5. When you find the frame you want, click Mark In to specify that frame as the starting point of the clip. The tape will continue playing. 6. Click Mark Out at the frame you want to serve as the end point of the clip. 7. If you are using several tapes, provide a unique ID (such as 1, 2, 3, or A, B, C) in Tape ID. 8. Click Add EDL Entry to add the clip to the edit decision list. 9. To edit the clip, click it in the list, and then click the Edit button. 10. Repeat steps 4 through 8 to add more clips. 11. When you are satisfied with the list, click OK and then, on the toolbar, click Start Encoding. During encoding, the EDL tab of the Monitor panel displays status information for the clips. Setting up an EDL To enable device control To encode to a file Capturing screens You can capture your entire desktop screen, individual windows, or a region of the screen and broadcast the screen or encode it to a file just as you would any other content. You can use the screen capture feature for: Capturing from.avi files that were created with a third-party screen-capture utility. Capturing a window (or the entire desktop) directly from your desktop. Capturing from a card that is connected to a scan converter device.

23 Page 23 of 100 When you capture a window, you can save the session for later use. Keep in mind, however, that the title of the window and its coordinates are saved along with all the other configuration information in the session file. When you reload the session file for a subsequent screen-capture session, the encoder looks for a window that matches the stored title. If the encoder does not find one, it captures a window that matches the stored coordinates. When you capture the entire desktop and save the session, the display size and color settings for your monitor are saved in the session file. If, after saving the session, you decide to change the screen size or color, you must create a new session to include these settings. If your screen saver is displayed while you are capturing a window or the entire desktop, the screen saver will be encoded. Therefore, it is recommended that you turn off your screen saver when capturing a window or the entire desktop. Notes Artifacts can be introduced when an analog signal is run through a scan converter and converted to National Television Standards Committee (NTSC) format. These artifacts are amplified during encoding and can degrade the quality of the encoded video. When you are done capturing a screen, be sure to click Stop encoding on the toolbar. Simply minimizing the window being captured does not end the encoding session. Configuring sources Improving performance when encoding screens To encode an.avi file containing screen content To capture a screen on the desktop Improving performance when encoding screens Because of the amount of data being manipulated and the CPU power required, capturing screens is a performance-intensive process. Use the following guidelines to ensure that the screen image you capture will encode and play well: Use a fast processor. Use the Windows Media Video 9 Screen codec. Set your monitor to use a lower display size. For example, capturing at a 1024 x 768 resolution yields more data than capturing at 640 x 480. Set your color display to 16-bit or 8-bit color. Or, to further improve the CPU usage set the encoder to run in 256-color mode. Keep in mind that running in 256 colors can introduce a palette change when switching between programs that have different color schemes. The encoder does not support palette changes for real-time screen capture. Therefore, you should use 16-bit colors or capture to an.avi file first, then use the encoder to convert the file to Windows Media Format.

24 Page 24 of 100 Use a low frame rate. You may have to experiment with the setting to determine the frame rate that meets your needs. Capture a smaller image. Use a higher bit rate. Avoid multiple scene changes, such as opening and closing windows in rapid succession during the capture. Capture screens or regions only from the primary monitor when using a dual-monitor scenario. Disable hardware acceleration. (However, enable hardware acceleration after completing the screen capture for best results with other programs.) Quit all video programs you are not using. Set up the output frame size to be the same as the source. Do not use the encoder to resize the source video. Capturing screens Hardware and software requirements To encode an.avi file containing screen content 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click File, and then enter the name of the.avi file. 3. Click the Compression tab. 4. In Destination, click either Windows Media server or Web server, depending on your playback scenario. 5. In Video, click Screen capture. 6. Click Apply, and then on the toolbar, click Start Encoding. Note When capturing from.avi files created by using a third-party screen capture tool, use runlength encoding (RLE) compression or RGB uncompressed formats for files you plan to later convert through the encoder. Capturing screens

25 Page 25 of 100 To capture a screen on the desktop 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. In Video, click Screen Capture, and then click Configure to specify the window or region of the screen that you want to capture. 4. Click the Compression tab. 5. In Destination, click either Windows Media server or Web server, depending on your playback scenario. 6. In Video, click Screen capture. 7. Click Apply, and then on the toolbar, click Start Encoding. The encoder window minimizes while you are encoding. If you are encoding a file, restoring the encoder window usually pauses the encoder. However, if your screen capture session is also sourcing audio from a file, then restoring the encoder window will not pause the encoder. For a broadcast session, encoding continues, even if you restore the encoder window. To stop or pause encoding, click the encoder button on the taskbar. Then, on the toolbar, click either Stop Encoding or Pause Encoding. Capturing screens Inserting script commands You can insert script commands into a stream while you are encoding. The encoder supports the following types of script commands: Captions. Free-form text strings that are displayed in a player along with your encoded content. For the captions to be visible, users must have enabled captions in their player. Closed captioning. If your capture card supports capturing closed captioning data, you can encode the closed captioning. URLs. When inserted into a stream, the user's default browser opens and the requested URL loads into the browser. If you have embedded the player within a browser, the requested URL replaces the player, and users cannot view the rest of the stream. You can get around this either by displaying the requested URL in a separate frame in the same browser instance or by opening an additional instance of the browser. Custom script commands. In addition to supporting captions and URLs, a player automatically processes FILENAME, EVENT, and OPENEVENT script commands. You can use the FILENAME command to open a specific digital media file at the time you specify. You can use the EVENT command to create custom script commands. For example, you can insert an advertisement into the stream. Note that the code for the specified event must be defined in the Windows Media metafile for the stream for the player to perform the specified event. The OPENEVENT command precedes the actual EVENT command. The OPENEVENT command allows the player to prebuffer the content so that when the specified

26 Page 26 of 100 event occurs, the switch between streams appears to be seamless. For detailed information about the script commands supported by Windows Media Player 9 Series, see the Windows Media Player 9 Series Software Development Kit (SDK). For information about the script commands supported by Windows Media Services 9 Series, see the Windows Media Services 9 Series SDK. Because script commands are saved in the stream, they are not available for editing. Inserting script commands into an encoding session requires that you select scripts as a source type when setting up your session. You cannot include scripts when you set up a session using the New Session Wizard, but you can add scripts to the session through the Sources tab of the Properties panel. Configuring sources To insert script commands while encoding To encode closed captioning data To insert script commands while encoding 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. -or- To insert script commands while sourcing from a file, click Both device and file. 3. Select the Script check box, and then click Script Panel. 4. Click Apply, and then click Start Encoding. 5. On the Script panel, click the button for the kind of script you want to insert. You can insert a caption (text string), URL, or custom script command. 6. Do one of the following: If you are inserting a caption or URL, type the text or URL that you want to insert. If you are inserting a custom script, type the script command type and value. 7. Click Insert at the point you want to insert the script into the stream. The Total scripts entry on the Monitor panel increments with each script command that you insert. Inserting script commands

27 Page 27 of 100 To encode closed captioning data 1. On the toolbar, click Properties, and then click the Sources tab. 2. In Source from, click Devices. 3. Select the Script check box, and then click the name of the capture card that supports closed captioning. 4. If you want to configure the card, click Configure. Inserting script commands Using multiple sources in a session You can use multiple sources in a session. Although only one source streams at a time, as you encode, you can switch between sources to stream different content. For example, before broadcasting a company meeting, you can set up sources for the main content as well as for welcome, intermission, and goodbye content. When you broadcast the event, you can start with the welcome source, switch to the main speaker when appropriate, switch to the intermission source during a break, and then switch to the goodbye source when the event finishes. If you are using the Windows Media Audio 9 Voice codec in a multisource session, the mode (voiceonly or mixed voice and music) of the first source determines the mode of the subsequent sources. For example, if you choose the voice-only or mixed mode for the first source, subsequent sources will be encoded in the same mode. However, if you specify the mixed mode for the first source and set up an optimization definition file for that source, subsequent sources in the session will be encoded in the voice-only mode. Configuring sources To switch between multiple sources while encoding To set the order of multiple sources

28 Page 28 of 100 To switch between multiple sources while encoding 1. On the View menu, click Sources Panel. 2. On the Sources panel, click the source you want to start with, and then click Start Encoding. 3. To switch to a different source, on the Sources panel, click the button for that source. Using multiple sources in a session To set the order of multiple sources 1. On the toolbar, click Properties, and then click the Sources tab. 2. In the list of sources, click the source you want to move, and then click the Up arrow button or Down arrow button. Using multiple sources in a session Customizing a session This section provides information about options you have for customizing an encoding session to meet your needs. If you customize a session and want to reuse it frequently, you can save the session to a session file and then add it to the list of quick starts. Windows Media Encoder To open an existing session To save a session To start, stop, or pause encoding

29 Page 29 of 100 To create a custom quick start Cropping and resizing video before encoding Preserving the pixel aspect ratio of video Optimizing video and audio Specifying a language for content Applying time compression to your content Using CBR encoding Using VBR encoding Setting up an MBR stream Using digital rights management to protect content Embedding a watermark in content Using hardware profiles Using transform plug-ins To open an existing session 1. On the File menu, click Open. 2. In File name, enter the name and location of the session file you want to open. Session files have a.wme file name extension. 3. Click Open. Note You can also open a session file by dragging it to the encoder. Customizing a session To save a session 1. On the File menu, click Save. 2. In File name, enter a name and location for the file, and then click Save.

30 Page 30 of 100 Customizing a session To start, stop, or pause encoding To start encoding, on the toolbar, click Start Encoding. A message notifies you that encoding has started. -or- To stop encoding, on the toolbar, click Stop. A message notifies you when encoding has stopped. A summary of the session results is available in the Encoding Results dialog box. -or- To pause encoding, on the toolbar, click Pause. Note that it is only possible to pause encoding when you are sourcing from devices or screen captures and encoding to a file. If any source in your session is a file, it is not possible to pause encoding. Customizing a session To create a custom quick start 1. Create a session that meets your encoding needs, and then save the session. 2. Save the session file to the Templates directory, which is in the same location as Windows Media Encoder. By default, this is C:\Program Files\Windows Media Components\Encoder\Templates. Your quick start will appear in the list of quick starts in the New Session dialog box. Customizing a session Using quick starts to encode

31 Page 31 of 100 Cropping and resizing video before encoding Using Windows Media Encoder, you can crop the edges of your input video image. For example, noise often occurs at the edges of an image, so you can crop one or more edges to eliminate the affected rows. You can specify how much to crop from each side of an image, or you can use default values for cropping. After cropping, you can resize the height and width of the output video. By default, the output video image is stretched to match the frame size specified in the profile. However, you can resize the video so that the output image matches the dimensions of the cropped image. Or, you can have the video resize automatically to make use of the bandwidth specified in the profile. You can also specify custom resize dimensions. MBR video and multiple sources If you are encoding MBR video, you can resize the output frame size for each bit rate separately. This means that an MBR file or stream can contain video images of varying sizes. If you have multiple sources in a session, the output dimensions of the first source determine those of the subsequent sources. Therefore, it is only possible to resize the first source in a multisource session. Detecting the input size When you source from a file, the encoder can detect the size of the source video before encoding begins; when you source from devices or screen captures, the input size cannot be detected before encoding. For this reason, when sourcing from devices or screen captures, you should specify the input size when you crop and resize video. When you do so, the encoder will detect the actual input size when encoding begins. If the actual input size is different than the size you specified, the percentage of cropping you specified (rather than the actual pixel values) will be applied to the actual input size. For example, assume you indicated that the input size was 100 x 200 pixels, and specified the following crop values: Top: 4 (2 percent of height) Bottom: 4 (2 percent of height) Left: 10 (10 percent of width) Right: 10 (10 percent of width ) If the encoder detected that the actual input size is 200 x 400, the actual crop values would match the percentage of cropping, as follows: Top: 8 (2 percent of height) Bottom: 8 (2 percent of height) Left: 20 (10 percent of width) Right: 20 (10 percent of width ) Hardware cropping

32 Page 32 of 100 If your capture card supports hardware cropping, it is recommended that you use the hardware to crop the video. Refer to the documentation for your capture card for information about hardware cropping. If your capture card does not support hardware cropping, or if you are sourcing from a file, the cropped video will not be displayed in the Input area on the Video panel until you start encoding. Resizing For best results, do not resize your output video. Resizing can result in suboptimal output. However, if you are encoding to a file by using the Windows Media Video 9 codec, and the time required to encode is not important, you can improve the quality of resized content by adjusting the encoder performance setting for the Encode to file option to better quality. Note that the encoding time increases significantly if you use this method. Caution You should not resize the image when you are encoding a screen, which can result in poor quality in the encoded content. Customizing a session Adjusting encoder performance settings To crop and resize video To match the frame size of the source video To match the frame size of the source video 1. On the toolbar, click Properties, and then click the Compression tab. 2. Click Edit, and then click the bit rate tab. 3. Select the Same as video input check box. Cropping and resizing video before encoding To crop and resize video

33 Page 33 of On the toolbar, click Properties, and then click the Video Size tab. 2. In the source list, click the source that you want to crop. (Only necessary for multisource sessions.) 3. If you are sourcing from devices or screens, in Crop, type the input size. 4. In Crop Method, click Custom or one of the default crop values. 5. If you selected custom cropping, enter the number of pixels to trim from the top, bottom, left, and right sides of the video. 6. In Resize method, click one of the following: Same as profile. Stretches the dimensions of the output video to match the frame size specified in the profile. No resizing. The dimensions of the output video match the dimensions of the cropped input video. Auto. When the source is a file, the dimensions of the output video are resized to make use of the bandwidth specified in the profile, while simultaneously attempting to maintain the aspect ratio of the cropped input image. If the input size you specified in step 4 is different than the actual input size, then the dimensions of the output video match the dimensions of the cropped input video. Custom. Enables you to specify custom dimensions for the output video. 7. If you are encoding MBR content, click a different bit rate and resize it. (This option is only available if you selected the Custom or Same as profile resize method for the first bit rate.) Note If you are cropping content that is also being deinterlaced or to which you are applying the inverse telecine filter, then the top and bottom cropping values must each be evenly divisible by 2. Cropping and resizing video before encoding Optimizing video and audio Preserving the pixel aspect ratio of video If your video source has nonsquare pixels, you can preserve its pixel aspect ratio. Check the documentation for your video device to determine whether it uses nonsquare pixels. The pixel aspect ratio is the width (x) of the pixel with respect to its height (y). A square pixel has a ratio of 1:1, but a nonsquare (rectangular) pixel does not have the same height and width. This concept is similar to the frame aspect ratio, which is the total width of an image with respect to its height. However, these aspect ratios are not necessarily tied together. For example, a widescreen image with a frame aspect ratio of 16:9 can be made of square or nonsquare pixels.

34 Page 34 of 100 If you encode a video source with nonsquare pixels as though the pixels are square, the output will distort, as shown in the following diagram. If you know the frame aspect ratio (Ix:Iy) and exact height and width of your image source, you can use the following formula to determine the x and y values of the pixel aspect ratio. PixelAspectRatioX / PixelAspectRatioY = (Ix * height) / (Iy * width) For example, if your image is 720 by 360 pixels, and the frame aspect ratio is widescreen (16:9), then PixelAspectRatioX=8 and PixelAspectRatioY=9: PixelAspectRatioX / PixelAspectRatioY = (16*360) / (9*720) = 8/9 Notes If you set the size of the output video to be the same as the source video, and the source video has nonsquare pixels, then the pixel aspect ratio of your source video is automatically preserved in the output video. Preserving the pixel aspect ratio of video increases the file size or stream bit rate. Customizing a session To preserve the pixel aspect ratio of video

35 Page 35 of 100 To match the frame size of the source video To preserve the pixel aspect ratio of video 1. On the toolbar, click Properties, click the Compression tab, and then click Edit. 2. On the General tab, select the Allow nonsquare pixel output check box, and then click OK. 3. Click the Video Size tab, and then in Pixel aspect ratio, specify the pixel aspect ratio of your input video. If you are using a custom pixel aspect ratio, the values you type must be between 1 and 255. Preserving the pixel aspect ratio of video Optimizing video and audio You can use Windows Media Encoder to deinterlace source video that is interlaced, apply an inverse telecine filter to content that is telecined, or maintain the interlacing in your source video. If you are not sure whether your source content is interlaced or telecined, you can use the encoder to detect the format by clicking Detect on the Processing tab of the Properties panel. If your audio content is primarily voice, combined with some music, you can use the Windows Media Audio 9 Voice codec and optimize the content for voice. Customizing a session Deinterlacing or maintaining the interlacing in video Applying the inverse telecine filter to video Optimizing audio for voice

36 Page 36 of 100 Deinterlacing or maintaining the interlacing in video A video frame can be either interlaced or progressive. An interlaced video frame contains two fields per frame captured at different time instants. When the video is being rendered, the lines of one field are displayed first, and then the lines of the second field are displayed. In contrast, with a progressive video frame, the lines in each frame are painted sequentially. Interlaced content is common because the NTSC and PAL standards use interlaced video signals. Deinterlacing video When interlaced video is played on a progressive-scan display, such as a computer, it can appear to flicker as the fields are rendered. Deinterlacing is the process of creating a progressive frame of video out of an interlaced frame, which reduces the flickering. The encoder has three deinterlace filters. The filter used by the encoder depends on the difference between the input and output frame size and frame rate. Normal deinterlacing. This is the default filter used when you select the deinterlace option. This filter blends the even and odd fields of an interlaced frame to create a progressive frame, as shown in the following diagram. Half-size deinterlacing. This filter is used when the number of lines specified for the output video is half (or less) than those of the input video. For example, this filter is used when the resolution of the input video frames is 640x480 pixels and the output resolution is 320x240 pixels. This filter uses an algorithm that blends the fields, rather than simply removing one field of data. This results in higher-quality output video. Half-size, double frame rate deinterlacing. This filter is used when the number of lines specified for the output video is half (or less) than those of the input video and the output frame rate is twice as high as the input frame rate. This filter produces a frame from each field of the video sequence, as shown in the following diagram.

37 Page 37 of 100 The benefits of this filter are that it produces high-quality progressive frames because there is no need to blend information across fields. In addition, the full motion of the interlaced fields is maintained. However, this filter has higher performance and bit rate requirements. Deinterlacing is not supported for a source that was not previously interlaced. Maintaining interlacing in source video Maintaining the interlacing in your video is useful if it will be displayed on interlaced playback devices, such as televisions. You must use the Windows Media Video 9 codec to be able to use this option. In addition, the user playing your content must have Microsoft Windows XP, a player that is based on the Windows Media Format 9 Series Software Development Kit (SDK), and a graphic card that supports interlacing; otherwise, your content is automatically deinterlaced. If your source video is mixed (progressive and interlaced) and you select the Maintain interlacing option, the output video will also be mixed. Notes Some capture cards support hardware deinterlacing. It is recommended that you use hardware deinterlacing if possible. Maintaining interlacing in source video when encoding at a low frame rate (for example, 15 fps) can introduce undesirable artifacts in the encoded content. Therefore, if you are encoding at a low frame rate, it is recommended that you deinterlace the video, even if the content is intended for display on an interlaced playback device. Optimizing video and audio To deinterlace video To maintain the interlacing in video To deinterlace video 1. On the toolbar, click Properties, and then click the Processing tab. 2. Click the source that you want to deinterlace. (Only necessary for a multisource session.)

38 Page 38 of Click Deinterlace. Notes Use the deinterlace filter only with a video source that was previously interlaced. Do not use the deinterlace filter when capturing screens. Deinterlacing or maintaining the interlacing in video To maintain the interlacing in video 1. On the toolbar, click Properties, and then click the Compression tab. 2. Click Edit, and then select the Allow interlaced processing check box. 3. Click the Processing tab. 4. Click the source that you want to maintain the interlacing for. (Only necessary for a multisource session.) 5. Click Maintain interlacing. 6. If you know which field is first in your content, click either Top first or Bottom first. If you are not sure which field is first, click Auto. Note You must use the Windows Media Video 9 codec to maintain interlacing in video. Deinterlacing or maintaining the interlacing in video Applying the inverse telecine filter to video The inverse telecine process removes frames that were added during telecining when film (24 fps) was converted to NTSC video (29.97 or 30 fps). The inverse telecine filter removes artifacts and improves the quality of encoded content, especially at low bit rates. Content is telecined in a pattern called 3:2 pulldown, which refers to the process used to create the

39 Page 39 of 100 extra frames. If the 3:2 pulldown pattern is consistent throughout the source video, the video is said to be coherent. However, video often is not coherent, meaning that there are breaks in the 3:2 pulldown pattern. For example, pattern breaks, or incoherencies, can be introduced when video is edited. If your content is coherent, you can choose the exact frame at which the 3:2 pulldown pattern starts. Or, you can choose to have the pattern be detected automatically. Inverse telecine is not supported for: An NTSC source that was not previously telecined. Content that has time compression applied. Content for which you are preserving or creating a time code. Optimizing video and audio To apply an inverse telecine filter to video To apply an inverse telecine filter to video 1. On the toolbar, click Properties, and then click the Processing tab. 2. Click the source that you want to apply the inverse telecine filter. (Only necessary for a multisource session.) 3. Click Inverse telecine. 4. If your content is coherent and you want to limit any pattern-break adjustments, in the list, click the frame where your shot begins. Notes Use the inverse telecine filter only with a video source that was previously telecined with a frame rate of 30 fps. Do not use the inverse telecine filter when capturing screens. Applying the inverse telecine filter to video Optimizing audio for voice

40 Page 40 of 100 If you are sourcing from audio that is entirely or primarily voice, you should use the Windows Media Audio 9 Voice codec, which is designed to encode voice. You can optimize the codec behavior by identifying if the content is voice only or if it also contains some music. If the audio is a mixture of voice and music, during encoding the codec automatically uses the appropriate algorithm to optimize encoding for the content (voice or music). Or, you can create an optimization definition file, which is a text file that identifies the places in your file where music starts and ends. The unspecified portions in the file are treated as voice. If you are using the Windows Media Audio 9 Voice codec in a multisource session, see Using multiple sources in a session for information about codec behavior. Optimizing video and audio To optimize audio for voice To create an audio optimization definition file To optimize audio for voice 1. On the toolbar, click Properties, and then click the Compression tab. 2. Click Edit, and then, in Mode, click CBR. 3. In Codec, click Windows Media Audio 9 Voice, and then click OK. 4. Click the Processing tab, and then click Voice only or Audio with voice emphasis. For audio with voice emphasis, you have the option of creating an optimization definition file, which identifies the places in the audio where music starts and ends. 5. If you created an optimization definition file, enter the name of the file. Optimizing audio for voice To create an audio optimization definition file To create an audio optimization definition file 1. Use a text editor, such as Notepad to create a text file. 2. Type the version number and the number of music segments the file contains.

41 Page 41 of 100 The version number should always be the number Type the start and end times (in milliseconds) of each segment, and separate each start and end time with a comma. For example, typing 1, 3, 0, 10000, 50000, 80000, , and indicates that there are three music segments; the codec will switch to music mode at 0 to 10 seconds, 50 to 80 seconds, and 150 to 200 seconds. 4. Encode the text file in Unicode. If you use Notepad to create the file, you can save the file as Unicode by choosing the Save As command on the File menu, and then, in Encoding, clicking Unicode. Optimizing audio for voice Specifying a language for content When you encode content, a language is automatically associated with your content. If you want, you can encode content in different languages. You can then use Windows Media Stream Editor to add content of different languages into one file. Then, users can choose the language they want to listen to when playing the file. To specify a language for content To specify a language for content 1. On the toolbar, click Properties, click the Compression tab. 2. Click Edit. 3. In Language, click a language from the list.

42 Page 42 of 100 Specifying a language for content Applying time compression to your content By applying time compression to your content while it is encoding, you can speed up or slow down the content during playback. Speeding up the content reduces the amount of time required to view the entire video or listen to the entire audio file, which is useful when you have to fit content into a specific time slot. Slowing down the content can improve comprehension in situations where the material is highly technical or the language is not native to users. Using time compression has the following requirements: Your source must include audio content. Every source in the session must be a file. You must encode to a file. (Time compression is not supported for broadcasts.) You must be using a one-pass encoding mode (either one-pass CBR or quality-based VBR). You cannot apply the inverse telecine filter in conjunction with time compression. You cannot use the looping feature in conjunction with time compression. You cannot apply time compression when sourcing from multichannel audio. If you are sourcing audio and video from separate files, encoding will stop when the end of the file with the shorter duration is reached. Windows Media Encoder has two time compression features that you can use independently of one another or in tandem: Accelerating or decelerating the audio and video frames. Accelerating and decelerating have no effect on the pitch of the audio stream. Detecting and removing pauses in voice or action. Periods of silence are removed from the audio, and frames are removed from the video. If you elect to create a log file, the start and end times of the segments that are removed are listed in the log file so you have a permanent record. Before using time compression, be sure you start with audio that is the best quality possible. Artifacts or noise in the source content will be more pronounced when the content is accelerated. Noise in the source content also decreases the accuracy of pause removal. Always test your content to ensure that you achieve the desired results. To run a test, encode some content by using time compression and then play it. If the results are unsatisfactory, adjust the time compression settings, and then encode the content again. Customizing a session To accelerate or decelerate the audio and video frames To remove pauses from the content

43 Page 43 of 100 To accelerate or decelerate the audio and video frames 1. Set up a session that sources from files. 2. On the toolbar, click Properties, and then click the Compression tab. 3. Select the Time Compression check box, and then click Properties. 4. Move the slider to adjust the amount of acceleration applied to your content. You can decelerate up to 50 percent or accelerate up to 250 percent. Applying time compression to your content To source from a file To remove pauses from the content 1. Set up a session that sources from files. 2. On the toolbar, click Properties, and then click the Compression tab. 3. Select the Time Compression check box, and then click Properties. 4. Select the Enable pause removal check box. 5. If you want to create a log file that will list the segments that are removed with a time stamp, click Options, and then enter a log file name. Applying time compression to your content To source from a file Using CBR encoding With CBR encoding, you specify the bit rate that you want to maintain and then set the size of the

44 Page 44 of 100 buffer. The bit rate will fluctuate across the stream; however, the fluctuations are constrained by the buffer size. The content quality also fluctuates to ensure that the buffer does not overflow or underflow. (If you want to guarantee the quality of the encoded output, use quality-based VBR encoding.) The size of the buffer determines the amount of initial delay when the content is played, but using CBR encoding ensures that the content is streamed smoothly, assuming that the bit rate is compatible with the client connection speed. If possible, use two-pass CBR encoding to reach a higher quality without losing the advantages of CBR encoding. Two-pass encoding is not supported in all scenarios. Customizing a session About CBR or VBR encoding About one- or two-pass encoding Feature requirements To set up a CBR encoding session To set up a CBR encoding session 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click a destination that supports CBR encoding and meets your playback scenario. 3. In Video and Audio, select the video and audio settings you want. 4. If you want to enable two-pass CBR encoding, select the Two-pass encoding check box. Note Two-pass encoding is not available for certain scenarios. Using CBR encoding About one- or two-pass encoding Feature requirements Using VBR encoding Windows Media Encoder supports three VBR encoding modes:

45 Page 45 of 100 Quality-based VBR. With quality-based VBR encoding, you specify a desired quality level (from 0 to 100). Then, during encoding, the bit rate fluctuates according to the complexity of the stream a higher bit rate is used for intense detail or high motion, and a lower bit rate is used for simpler content. The advantage of quality-based VBR encoding is that quality remains consistent across all streams for which you specify the same quality setting. The disadvantage is that you cannot predict the file size or bandwidth requirements of the encoded content before encoding. Quality-based VBR encoding uses one-pass encoding. This mode is good for archiving content. If you are encoding audio content with this encoding mode, you have the option of using the Windows Media Audio 9 Lossless codec. Lossless encoding produces superior quality results, while also providing some compression of the data. Bit rate-based VBR. With bit rate-based VBR encoding, you specify the desired average bit rate. At any point, the bit rate may exceed the average bit rate but the overall bit rate does not exceed the average bit rate. Bit rate-based VBR encoding uses two-pass encoding. In the first pass, the data complexities are analyzed. Then, in the second pass, the quality level is set to achieve the average bit rate. The advantage of bit rate-based VBR encoding is that the compressed stream will achieve the highest possible quality level while staying within a predictable average bandwidth. Peak bit rate-based VBR. Peak bit rate-based VBR encoding is similar to the bit rate-based mode, except that you also specify the peak bit rate. The encoder determines the image quality that can be achieved without exceeding the peak bit rate. The bit rate does fluctuate during encoding, but does not exceed the specified peak bit rate. Use this option when you plan to distribute the content for playback on a device that has a constrained reading speed, such as a CD or DVD player. Peak bit rate-based VBR encoding uses two-pass encoding. Notes Only certain codecs support VBR encoding. The quality-based and bit rate-based VBR encoding modes are not recommended for use in a streaming scenario as a result of the high bit rate peaks in the content. In a streaming scenario, when all players reach the point in the stream with a high bit rate at approximately the same time, there is a large peak in demand. This peak may exceed the network capacity, resulting in a negative playback experience. Customizing a session About CBR or VBR encoding Using CBR encoding Feature requirements About one- or two-pass encoding To set up a quality-based VBR encoding session To encode lossless audio To set up a bit rate-based VBR encoding session To set up a peak bit rate-based VBR encoding session

46 Page 46 of 100 To set up a quality-based VBR encoding session 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click File archive. 3. In Video and Audio, select the quality settings you want for video and audio. -or- Click Edit, click the Quality-based tab, and then, in Video quality, type the quality setting you want. The setting can range from 0 to 100, with 100 being the highest quality. Using VBR encoding To encode lossless audio 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click File archive. 3. In Audio, click Lossless quality audio. Using VBR encoding To set up a bit rate-based VBR encoding session 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click File download. 3. In Video and Audio, select the settings you want for video and audio. -or-

47 Page 47 of 100 Note Specify your own settings by clicking Edit. This VBR mode uses two-pass encoding. Two-pass encoding is not available for certain scenarios. Using VBR encoding About one- or two-pass encoding To set up a peak bit rate-based VBR encoding session 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Hardware devices. 3. In Video and Audio, select the settings you want for video and audio. Note -or- Specify your own settings by clicking Edit. This VBR mode uses two-pass encoding. Two-pass encoding is not available for certain scenarios. Using VBR encoding About one- or two-pass encoding Setting up an MBR stream If you plan to deliver your content as a unicast stream from a server running Microsoft Windows Media Services, encoding multiple-bit-rate (MBR) stream provides users with better quality content during times of network congestion. When you set up an MBR stream, your content is encoded at

48 Page 48 of 100 each bit rate that you specify. When a player receives an MBR stream, only the stream that is the most appropriate for current network conditions plays. The Windows Media server and player handle the process of selecting the appropriate stream, which is invisible to the user. Because an MBR stream is intended for use only in a streaming scenario, you can only use CBR encoding when encoding an MBR stream. You can encode an MBR stream for both audio and video content; however, it is not necessary to use MBR encoding for both audio and video in a stream. For example, you can stream audio at one bit rate and have multiple bit rates for the video portion of the stream. When setting up an MBR stream, keep in mind that the more bit rates you select, the larger the aggregate bandwidth for live stream distribution from the encoder to a Windows Media server is required. To estimate the aggregate bandwidth of an MBR profile, calculate the sum of each audio and video bit rate, and the script bit rate. Also keep in mind that encoding an MBR stream uses more processing power for the encoding computer. If you are using the Windows Media Audio 9 Voice codec in an MBR session and you specify the mixed voice and music mode, it is recommended that you do not include any bit rates below 8 kilobits per second (Kbps) in the session. The reason for this is that any bit rates below 8 Kbps will be encoded in voice-only mode, which may result in suboptimal quality in your audio content. Customizing a session To encode an MBR stream To encode single-bit rate audio with MBR video To encode single-bit rate video with MBR audio To encode an MBR stream 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Windows Media server. 3. In Video and Audio, click the quality settings you want. 4. In Bit rates, select the bit rates you want to stream at. -or- Notes Click Edit, and then click Add. The Add Bit Rate dialog box appears. Type a bit rate you want to include in the MBR stream. Select a range of bit rates that you think will meet the playback needs of the audiences you are targeting. It is not necessary to use MBR encoding for both audio and video in a stream. For example, you can stream audio at one bit rate and have multiple bit rates for the video portion of the

49 Page 49 of 100 stream. Setting up an MBR stream To encode single-bit rate audio with MBR video To encode single-bit rate video with MBR audio To encode single-bit rate audio with MBR video 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Windows Media server. 3. In Video and Audio, click the quality settings you want to use. 4. In Bit rates, select the bit rates you want to stream at. 5. Click Edit, and then on each bit rate tab, select the same setting in Audio format. Setting up an MBR stream To encode single-bit rate video with MBR audio To encode single-bit rate video with MBR audio 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Windows Media server. 3. In Video and Audio, click the quality settings you want to use. 4. In Bit rates, select the bit rates you want to stream at. 5. Click Edit, and then, for each bit rate tab, select the same settings in the video area. (All settings must match, or multiple video bit rates are used during encoding.) Setting up an MBR stream To encode single-bit rate audio with MBR video

50 Page 50 of 100 Using digital rights management to protect content You can control the use of your encoded content by protecting it with digital rights management (DRM) technology while you are encoding. You can use DRM either when encoding to a file or when broadcasting the stream. Content is encoded, encrypted with a key, and then a license is required by users to play the content. This license contains the key to unlock the content and the rights that govern its use. For example, the license determines the number of times a user can play the content or when the license expires. Important Licenses are issued by a third-party license provider, so you must set up an account with one before you can protect your content. Steps involved in using DRM The basic steps in using DRM are as follows: 1. Set up an encoding session. 2. Set up an account with a license provider (if you haven't already done so) and create a DRM profile. 3. In the session, identify the DRM profile to use with the content. 4. Encode and distribute your content, either by streaming it or providing files for download. 5. When users play the protected content, the player acquires a license, which is issued by the license provider you chose. The user can then play the content according to the rights that are included in the license. For users to play protected content, they must use a player that supports Microsoft DRM technology. For a list of players, see the Microsoft Web site. Reusing DRM profiles After you have created a DRM profile, you can reuse it in future sessions. You can also export the profile so that you can import it for use on a different encoding computer. Similarly, you can import a DRM profile from another computer. To ensure security, DRM profiles are maintained on a peruser basis. This prevents others from viewing, editing, and using DRM profiles that you create. DRM profiles have a.drm file name extension. Customizing a session Setting up an account with a license provider To protect your content with DRM

51 Page 51 of 100 To protect your content with DRM 1. On the toolbar, click Properties, and then click Security. 2. If you have not already done so, set up an account with a license provider, and then create a profile. 3. Select the Use DRM to protect content from unauthorized use check box. 4. In DRM profile, select the profile in the list that you want to use with this session. When you begin encoding, your content is protected. Using digital rights management to protect content Setting up an account with a license provider Setting up an account with a license provider A license provider must issue the licenses for the content that you protect. You must set up an account with a license provider that supports Windows Media Encoder 9 Series. As part of setting up the account, the license provider will prompt you to select the rights you want to include in your licenses. Depending on the license server, you might be prompted to specify other settings, such as how you want to issue licenses. After you have set up an account, the license provider creates a DRM profile and saves it to your local computer. Then, you can use the profile to protect your content. The profile contains the following information: A DRM profile ID A name and description Attributes (name-value pairs) The URL to the license provider's Web site The license acquisition URLs Players can support different versions of Microsoft DRM technology: Windows Media Rights Manager version 1 or 7. Therefore, different license acquisition URLs are used that correspond to each version. Each license acquisition URL points to the page on the license provider's Web site where a license can be acquired and is included in the header of your protected content. When the user plays the protected content, the player opens the appropriate license acquisition URL to get a license.

52 Page 52 of 100 When a DRM profile is created, the following values are also created and stored on your local computer: Public and private signing keys. The license provider requires the public signing key to issue licenses. The private signing key is not returned. A license key seed. For each file or stream you want to protect, the seed is used to generate a key to encrypt the content. This value is also used by the license provider to regenerate this key and include it in a license, which is used by the user's player to decrypt the content. Using digital rights management to protect content To set up an account with a license provider To set up an account with a license provider 1. On the toolbar, click Properties, and then click Security. 2. Click New, and then click Add. 3. Do one of the following: Specify the name and URL of the provider you want to use. Click Find Provider to go to a Web site that contains a list of providers you can choose from. After you have identified a provider, the New Profile dialog box is displayed. 4. In the list, click the provider name, and then click Generate. The user interface provided by the provider is displayed. 5. Follow the instructions to create a DRM profile for your content. After you have created the profile, you can then use it to protect your content. Setting up an account with a license provider To protect your content with DRM

53 Page 53 of 100 Embedding a watermark in content You can embed a digital watermark into a stream. Watermarks are a way of adding information, such as a copyright or artist's name, to the audio and video stream, but watermarks are not audible or visible to the user. The watermark is preserved in the encoded file or stream and cannot be removed. The watermark can be used to identify content even if it is copied or edited. You must obtain and register a third-party plug-in to work with watermarks. For information about obtaining a watermark plug-in, see the Microsoft Web site. Customizing a session To add a watermark to your content To add a watermark to your content 1. If you haven't already done so, register the watermark plug-in you plan to use. 2. Start the encoder, and then on the View menu, click the Properties panel. 3. Click the Security tab. 4. If you want to add a watermark to video content, select the Video check box and then, in the list, click the plug-in you want to use. 5. If you want to add a watermark to audio content, select the Audio check box and then, in the list, click the plug-in you want to use. Note If the watermark plug-in you are using requires a configuration file, click Configure to specify the file. Embedding a watermark in content Using hardware profiles

54 Page 54 of 100 Windows Media-based content is no longer played back solely on computers. Instead, there is increasing demand for playing the content on various hardware devices, such as set-top boxes, wireless handsets, and DVD players. If you want to ensure that your content can be played on a certain type of hardware device, you can encode your content by using a hardware profile. Windows Media Encoder includes a number of hardware profiles, which are intended to meet a range of encoding needs. Even if you do not use a hardware profile to encode content, you can still determine the type of hardware device that can play the content. All encoded content is mapped to a hardware profile; the profile used to encode is indicated in the Encoding Results dialog box (in Profile conformance) that appears when encoding is complete. Video profiles Windows Media Encoder includes the following hardware profiles: simple low, simple medium main low, main medium, and main high. For more information about each profile, see Hardware profiles for video. A given profile and level always supports lower profiles and levels. For example, a device that supports the main profile, medium level, also supports the main profile, low level, and all levels in the simple profile. Audio profiles The following table lists, in ascending order, the hardware profiles for audio content included with the encoder. Audio profile L1 L2 L3 L S1 Description For audio bit rates from 64 Kbps to 128 Kbps (uses the Windows Media Audio 9 codec) For audio bit rates that are less than or equal to 160 Kbps (uses the Windows Media Audio 9 codec) For audio bit rates less than or equal to 384 Kbps (uses the Windows Media Audio 9 codec) Supports all bit rates; intended for playback on computers as a demonstration of codec capabilities (uses the Windows Media Audio 9 codec) For audio bit rates that are less than or equal to 20 Kbps, for low-complexity voice content (uses the Windows Media Audio 9 Voice codec) It is not possible to select the profiles listed in the following table when setting up a session. However, if the encoded audio meets the parameters listed in the table, the content will be mapped to the corresponding hardware profile. Audio profile S2 M1 Description For audio bit rates that are less than or equal to 20 Kbps, for mixed music and voice content (uses the Windows Media Audio 9 Voice codec) For audio bit rates that are less than or equal to 384 Kbps, sampling rate less than or equal to 48 KHz, and 5.1 or fewer channels; recommended for surround sound for standard-definition movies (uses the Windows Media Audio 9

55 Page 55 of 100 Professional codec) M2 M For audio bit rates that are less than or equal to 768 Kbps, sampling rate less than or equal to 96 KHz, and 5.1 or fewer channels; recommended for surround sound for high-definition movies (uses the Windows Media Audio 9 Professional codec) Supports all bit rates, sampling rates, and channels; intended for playback on computers as demonstration of codec capabilities (uses the Windows Media Audio 9 Professional codec) Combining video and audio profiles The following table lists recommended combinations of video and audio hardware profiles. Video Simple low Simple medium Main low Main medium Main high Audio L2 or S2 L2 or S2 L2 or S2 L3, S2, or M1 L3, S2, or M2 Customizing a session To set up a hardware profile Hardware profiles for video To set up a hardware profile 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Windows Media hardware profiles. 3. In Video and Audio, click the profile and level you want to encode at. Using hardware profiles

56 Page 56 of 100 Hardware profiles for video This topic provides detailed information about the hardware profiles available for video content that are installed with Windows Media Encoder. Simple low Item Target hardware devices Simple medium Main low Main medium Value Wireless handsets Maximum resolution 176 x 144 Maximum frame rate Maximum bit rate Maximum buffer size Item Target hardware devices 15 fps 96 Kbps About 3.4 seconds at maximum bit rate Value Maximum resolution 352 x 288 Maximum frame rate 15 fps at 352 x fps at 320 x 240 Maximum bit rate Maximum buffer size Item Target hardware devices Handheld computers, personal data assistants, and high-end wireless handsets 384 Kbps About 3.3 seconds at maximum bit rate Value Maximum resolution 352 x 288 Maximum frame rate Maximum bit rate Maximum buffer size Low-end set-top boxes 30 fps 2 Mbps About 2.5 seconds at maximum bit rate

57 Page 57 of 100 Item Target hardware devices Main high Using hardware profiles Value Maximum resolution 720 x 576 Maximum frame rate Maximum bit rate Maximum buffer size Item Target hardware devices High-end set-top boxes; DVD players; and DirectX Video Acceleration (VA)-enabled graphic cards 30 fps at 720 x 576 (NTSC) 25 fps at 720 x 576 (PAL) 10 Mbps About 1 second at maximum bit rate Value Maximum resolution 1920 x 1080 Maximum frame rate 30 fps at 1920 x fps at 1280 x 720 Maximum bit rate Maximum buffer size DVD players; DirectX VA-enabled graphic cards; and digital cinema 20 Mbps About 2 seconds at maximum bit rate Using transform plug-ins Windows Media Encoder has a customizable user interface that enables developers to write transform plug-ins that customize and build upon encoding functionality. The encoder supports Microsoft DirectShow and DirectX Media Object DMO transform filters. You can configure plug-ins on a per-source basis. For information about DirectShow, see the Microsoft Web site. For information about DirectX Media Object, see the Microsoft Web site. Customizing a session

58 Page 58 of 100 To use a transform plug-in To use a transform plug-in 1. On the toolbar, click Properties, and then click the Plug-ins tab. 2. In Transform plug-in type, click either Video or Audio. 3. Click the source that you want to use the plug-in with. (Only necessary for a multi-source session.) 4. If no plug-ins appear in the list of available plug-ins, click Register, and then select the check boxes for the plug-ins you want to use. (To unregister a plug-in, clear the check box for the plug-in.) You must have administrative credentials on the encoding computer to register a plug-in. 5. In the list of available plug-ins, click a plug-in, and then click the move right button (>>) to add it to the list of plug-ins for the source. 6. Click Configure to configure the selected plug-in. Caution The Register/Unregister Transform Plug-ins dialog box lists all transform plug-ins that are available on the encoding computer. Some of the plug-ins may not be appropriate for use with the encoder and may have unexpected results if you attempt to use them with the encoder. Using transform plug-ins Output options You can either encode content to a file for later use, or you can broadcast the content live. If you are broadcasting, you can either push the stream to a server running Windows Media Services or you can enable Windows Media servers and players to pull the stream directly from the encoder. You can archive a copy of the broadcast to a file. Before or after encoding, you can: Change the output port for a broadcast. Select or cancel archiving to a file. Change the name or location of the output file.

59 Page 59 of 100 While encoding, you can: Select or cancel archiving to a file. Change the name of the archive file if you are not currently archiving. While encoding, you cannot: Change the port number. Change from a broadcast session to an encode-to-file session. Windows Media Encoder Encoding or archiving a broadcast to a file Encoding uncompressed audio and video files Broadcasting content live Testing your content Encoding or archiving a broadcast to a file You can encode content to a file, and you can archive a live event to a file for later use. Archiving on a Windows Media server versus archiving on the encoding computer If you are broadcasting through a Windows Media server, you can archive the broadcast on the server rather than on the encoding computer. Archiving on the Windows Media server is the best solution when: You want the archive to be available immediately for viewing. The resources on your encoding computer are mostly being used for encoding. You have more disk space available on your server than on your encoding computer. If you choose to archive the broadcast on the encoding computer, all the sources you set up in the broadcast session are archived automatically. However, archiving all sources is not always desirable. For example, if one of the sources is an advertisement, you may not want to archive the advertisement. You can have the encoder automatically pause archiving for sources that you specify. Enabling seeking in the output file Indexing at each key frame is turned on by default whenever you archive or encode to a file and your source includes video. By indexing the content, users can make use of the fast-forward and rewind features of a player while viewing encoded content. Indexing is not available for broadcasts. You can also choose to enable frame-level seeking in an output file by generating a time code (or preserving the time code already present in the source video). You can generate a time code when your source includes video and you are sourcing from digital video (DV) files in Audio-Video Interleaved (AVI)

60 Page 60 of 100 format, capture devices, and digital devices. You can preserve a time code when your source includes video and you are sourcing from digital video (DV) files in Audio-Video Interleaved (AVI) format or digital devices. To preserve the time code for a VTR, you must set up an EDL for the session. You cannot preserve or create a time code when you are applying the inverse telecine filter. Storing content temporarily If you are encoding to a file while sourcing from devices, the encoding process might fall behind the capturing process, which reduces the quality of the encoded content. To prevent this from occurring, you can temporarily store the captured content and then encode it to a file. If you choose this option, capturing and encoding occur simultaneously and data is only stored temporarily if encoding falls behind. For the best quality, especially when capturing a large amount of data, you can choose to capture first and then encode only after you have stopped capturing. (This option is not available when you are sourcing from a digital device. In addition, it is not possible to capture first, and then encode in conjunction with limiting the size or duration of the output file.) If you enable this feature (including the option to capture first, and then encode) in a multisource session, you should wait until all data has been received from the first source before you stop encoding. For example, assume you have two sources, and only want to capture part of the second source. You can switch to the second source during encoding, but you should wait until the video preview/postview (on the Video panel) or the Input area (General tab of the Monitor panel) indicate that the first source has finished sending all data before you stop encoding. This ensures that you will capture all of the content you want. Output options About the.asf,.wma, and.wmv file name extensions Setting up an EDL To encode to a file To set archive options for each source To turn indexing on or off To enable frame-level seeking To store captured content temporarily Encoding uncompressed audio and video files About the.asf,.wma, and.wmv file name extensions The.asf,.wma, and.wmv file name extensions represent the standard Windows Media file format. The.asf file name extension is normally used with Windows Media-based content created by using Windows Media Tools 4.0. The.wma and.wmv file name extensions were introduced as standard naming conventions with Windows Media Encoder 7 to enable users to easily differentiate between audio-only (.wma) files and video (.wmv) files. However, the three extensions can be used

61 Page 61 of 100 interchangeably. Some tools and services that were created for use with earlier versions of Windows Media Technologies require the.asf extension to accept the content. You can simply rename any.wma or.wmv file with the.asf extension to use them with those tools. (However, it is recommended that you use the most current tool or service, when possible.) Encoding or archiving a broadcast to a file To encode to a file 1. On the toolbar, click Properties, and then click the Output tab. 2. Clear the Push to server and Pull from encoder check boxes. 3. Select the Encode to file check box. 4. In File name, enter the output file name. 5. If you want to limit the size of the output file, click Limit by size, and then type the maximum file size followed by a K, M, or G for kilobytes, megabytes, or gigabytes, respectively. 6. If you want to limit the duration of the output file, click Limit by duration, and then type the maximum duration of the file in hh:mm:ss; for example, 01:30:00. Encoding or archiving a broadcast to a file To set archive options for each source 1. On the toolbar, click Properties, and then click the Output tab. 2. Select a broadcast method (push or pull), and then select the Archive to file check box. 3. In File name, enter a name for the archive file. 4. If you want to limit the size of the archive file, click Limit by size, and then type the maximum file size followed by a K, M, or G for kilobytes, megabytes, or gigabytes, respectively. 5. If you want to limit the duration of the archive file, click Limit by duration, and then type the maximum duration of the file in hh:mm:ss, for example, 01:30: If you do not want all sources in the broadcast archived, click the Sources tab, and then in the sources list, click the source you do not want to archive. 7. In Archiving, click Pause or Stop to prevent the source from being archived.

62 Page 62 of 100 You can override these settings by using the Manual Archive Controls on the Control menu. Encoding or archiving a broadcast to a file To turn indexing on or off 1. On the toolbar, click Properties, and then click the Output tab. 2. Select the Encode to file or Archive to file check box. 3. Select or clear the Add index check box to turn indexing on or off, respectively. Note Indexing enables seeking to key frames. You can enable frame-level seeking for some content. Encoding or archiving a broadcast to a file To enable frame-level seeking To enable frame-level seeking 1. On the toolbar, click Properties, and then click the Advanced tab. 2. Select the Time code check box. 3. If the source video already has a time code, click Preserve original. Note -or- To generate a time code, click Create new time code and then, in Start time, type the time in the format hh:mm:ss:fm that you want the time code to start at. In addition, in Video format, select the format of the source video. You can generate a time code when your source includes video and you are sourcing from digital video (DV) files in Audio-Video Interleaved (AVI) format, capture devices, and digital devices. You can preserve a time code when your source includes video and you are sourcing

63 Page 63 of 100 from digital video (DV) files in Audio-Video Interleaved (AVI) format or digital devices. To preserve the time code for a VTR that is connected through a COM port using the Sony RS422 protocol, you must set up an EDL for the session. You cannot preserve or create a time code when you are applying the inverse telecine filter. Encoding or archiving a broadcast to a file To store captured content temporarily 1. On the toolbar, click Properties, and then click the Advanced tab. 2. Select the Store content to hard disk temporarily check box. 3. To capture first and then encode, select the Capture to hard disk first, then encode check box. Note The Capture to hard disk first, then encode option is not available when you are sourcing from a digital device. Encoding or archiving a broadcast to a file Encoding uncompressed audio and video files Using Windows Media Encoder, you can capture and archive high-quality content to an archive file for later use. For most situations, the File Archive option, which uses quality-based VBR encoding, is most appropriate. However, if you plan to edit the content at a later date, you may want to consider encoding uncompressed files. Storage requirements for uncompressed files are significantly higher than for other files to which compression has been applied. It is recommended that you store the content on an NTFS volume. The FAT32 file system has a file size limit of 4 GB. If you expect your content to exceed 4 GB, you should reconfigure your hard disk to use NTFS.

64 Page 64 of 100 When you capture uncompressed content from a device, such as a camera or VCR, the resulting video is created in the YUV format YV12, regardless of the pixel format specified on the device or in the profile. The Windows Media Video 9 codec is optimized for YUV, making it the preferred format for quality, size, and performance. The resulting audio is created in the pulse code modulation (PCM) format. For best results when capturing uncompressed content: Use a fast hard disk that can accommodate encoding at high bit rates. Use 15 fps when capturing 640 x 480 resolution. Use 30 fps when capturing 320 x 240 resolution. Output options To use the File Archive option To encode uncompressed content To use the File Archive option 1. On the toolbar, click Properties, and then click the Output tab. 2. Clear the Push and Pull check boxes, and then select the Encode to file check box. 3. Click the Compression tab, and then, in Destination, click File Archive. 4. In Video and Audio, select the quality settings you want. Encoding uncompressed audio and video files To encode uncompressed content 1. On the toolbar, click Properties, and then click the Compression tab. 2. In Destination, click Windows Media server or Web server, and then click Edit. 3. If you are encoding audio, select the Audio check box and then, in Codec, click None (PCM). 4. If you are encoding video, select the Video check box and then, in Codec, click Full frames (uncompressed). Notes

65 Page 65 of 100 When you encode both audio and video, you must use the uncompressed option for both. It is not possible to encode uncompressed content into an MBR stream. Encoding uncompressed audio and video files Broadcasting content live When you want to broadcast your content live, you can choose to either push the stream from the encoder to a Windows Media server or you can enable clients (Windows Media servers or players) to pull the content. The method you use depends upon your situation. Push scenarios Pushing a stream from the encoder is useful if the encoder is behind a firewall or if you want to initiate the connection from the encoder. For example, assume you have just received last-minute notice that the president of your company wants to stream a talk to the company employees. The Windows Media server is located remotely, outside your company firewall. In fact, it is the middle of the night for the server administrator. By pushing the stream from the encoder, you can get the stream past the firewall, meet the president's request, and avoid making an emergency call to bring someone in to administer the server. Push distribution is only available with Windows Media Services 9 Series in Windows.NET Server Pull scenarios Enabling Windows Media servers to pull a stream is useful in several scenarios. First, if there are multiple distribution servers, all connecting at different times, each server can initiate the connection with the encoder when the server is ready to stream. Next, pulling from a server is useful if it is important to minimize bandwidth usage between the server and the encoder. For example, the server administrator can add a publishing point and configure it to start automatically upon client request, which means that the server does not initiate the connection with the encoder until the first client connects. This eliminates unnecessary bandwidth use between the server and the encoder. (This scenario is only available with Windows Media Services 9 Series in Windows.NET Server 2003.) Finally, pulling from the server is also useful when the server is behind a firewall. For example, assume you have set up the encoder on a public network because you are streaming events at a conference. You need to get the stream to a distribution server in the protected network. The server administrator can pull the stream through the firewall. Enabling players to pull the stream is useful when you do not expect to have many clients viewing the stream. Windows Media Encoder allows up to five clients to connect directly to it during a broadcast. When you are enabling clients to pull the stream, you can restrict access to the content by IP address or by groups of IP addresses.

66 Page 66 of 100 Output options Comparing Windows Media servers and Web servers Pushing a stream from the encoder Enabling clients to pull a stream from the encoder Creating an announcement for a multicast Restricting access to a broadcast Pushing a stream from the encoder When pushing a stream from the encoder, you must specify the Windows Media server to which you want to stream and the broadcast publishing point (either new or existing) you want to stream through. On the Windows Media server, you have a number of options for configuring a publishing point, including setting limits on the number of players that can view the stream, controlling access to content, and setting up logging. If you have a configuration that you want to use repeatedly, you can add a broadcast publishing point on the server, configure it to meet your needs, and then copy the settings from that publishing point each time you push a stream to the server. For more information about configuring broadcast publishing points, see Windows Media Services Help. Push distribution is only available with Windows Media Services 9 Series in Windows.NET Server Content can be delivered from a Windows Media server either as a multicast or a unicast stream. Announcement required for a multicast stream If you are planning to deliver content as a multicast stream from the server, you must create and distribute an announcement before you begin encoding. An announcement is the means by which you communicate that your content is available to players. You can use the Multicast Announcement Wizard in the encoder to create the announcement. Or, alternatively, you can create the announcement on the server. Creating the announcement on the encoder requires that you have access permission to the Windows Media Services service through the distributed version of Component Object Model (DCOM). If you make any changes to the session configuration after you have created the announcement, you must create another announcement before you begin encoding. Accessing the Windows Media server To push a stream to a Windows Media server, the WMS HTTP Server Control Protocol plug-in must be enabled on the server. In addition, you must have write access permissions on the server through the WMS Publishing Points ACL Authorization plug-in. You must also have create access permissions for the plug-in if you want to add the publishing point from the encoder rather than from the server. The permissions must be set at both at the server level and at the publishing point level. To configure the plug-in, you must have access to the Windows Media Services service through DCOM. Local administrators on the server automatically have both write and create access permissions on the server.

67 Page 67 of 100 When you begin encoding, the encoder initiates the connection with the server. You can use the New Session Wizard or the broadcast quick start to push to a Windows Media server, or you can set up a push session on the Properties panel. For more information about setting up a multicast or unicast stream from a Windows Media server, see Windows Media Services Help. Broadcasting content live Creating an announcement for a multicast To push a stream to a Windows Media server To push a stream to a Windows Media server 1. On the toolbar, click Properties, and then click the Output tab. 2. Select the Push to server check box and clear the Pull from encoder check box. 3. In Server name, type the name of the Windows Media server from which you want to distribute the content. You can use the network basic input/output system (netbios) name, IP address, or Domain Name System (DNS) name of the server. The encoder uses the HTTP protocol to stream to the server. By default, the server uses port 80 for the HTTP protocol. If the server is configured to use a different port number, the encoder must match the port number. You can either use the format Server_name:Port_number in Server name or, if you have access permissions to the Windows Media Services service through DCOM, the port number is automatically detected. 4. In Publishing point, type the name of an existing or new publishing point you want to stream through. If you are creating a publishing point, use alphanumeric characters only. In addition, the following characters are not valid in a publishing point name: * < > \? % & # " { } ^ [ ] ` If you want to create a publishing point from the encoder, you must have create access permissions through the WMS Publishing Points ACL Authorization plug-in (at both the server and publishing point level) on the Windows Media server. 5. If you are creating a publishing point, you can use the configuration of the default publishing point or you can choose to copy the configuration an existing publishing point to the publishing point you are creating. To do so, in Copy settings from, type the name of the existing publishing point that has the configuration you want to copy. 6. If you want to remove the publishing point through which you are streaming after you close the encoder (or after a timeout of several minutes), select the Auto remove check box. The timeout enables you to stop and then restart encoding without having to create the publishing point. This is useful, for example, if you want to adjust settings in the session and then continue encoding.

68 Page 68 of 100 Note If you are planning to deliver the content as a multicast stream, you must also create an announcement. Pushing a stream from the encoder Creating an announcement for a multicast Creating an announcement for a multicast If you are pushing a stream to a Windows Media server and distributing it as a multicast stream, you must create an announcement (.asx) and multicast information (.nsc) file. The announcement is a Windows Media metafile that points players to the multicast information file. The multicast information file contains information that enables players to access and decode the multicast stream, including the IP address, port, and stream format information. Creating an announcement You can use the Multicast Announcement Wizard in the encoder to create the announcement, or you can create it on the Windows Media server. Creating the announcement on the encoder requires that you have access permission to the Windows Media Services service through DCOM. If you make any changes to the session configuration after you create the announcement, you must create another announcement before you begin encoding. When you run the wizard on the encoder, you create the announcement file, multicast information file, and a Web page that contains an embedded player and a link to the announcement. You are asked to provide a name for the files and to save the files to a storage location that is accessible to players (or to a temporary location, if you plan to broadcast later.) The storage location can be either on your Web server for HTTP access or on a public share if you are providing access using a Universal Naming Convention (UNC) path. If you make the files available from your Web server, be sure to configure the Web server to either not allow caching of the file or to require a refresh check when cached by a client to prevent players from using multicast information that is outdated. Distributing the announcement file You have several options for making the multicast stream available to users. You can place a link to the announcement file on a Web page, make the announcement available on a shared folder, or send the announcement in an message. Users can access the announcement either by clicking the link to the announcement on a Web page or by opening the announcement directly. When a user opens the announcement file (.asx) in the player, the player extracts an URL in the announcement file; the URL points to the multicast information file. The player then downloads the multicast information file with the URL and begins playing the content.

69 Page 69 of 100 Broadcasting content live To access the Multicast Announcement Wizard To access the Multicast Announcement Wizard 1. Set up a push session with a Windows Media server that will distribute content as multicast stream. 2. On the Tools menu, click Announce Broadcast. 3. Follow the instructions in the wizard to create the files for the session. Pushing a stream from the encoder Creating an announcement for a multicast Enabling clients to pull a stream from the encoder To enable clients to pull the stream from the encoder, you simply set up a session and begin broadcasting directly from the encoder. Clients (Windows Media servers or players) can connect to the stream at any time by using the following URL format: (for Internet connections) or (for LAN connections). The encoder supports up to five direct connections during a broadcast by default. You can increase this number to 50 by editing a key in the registry. (Editing the key requires administrative credentials on the encoding computer.) Stream format required for a multicast transmission If you plan to deliver content as a multicast stream from a Windows Media server, the server must be able to detect the stream format from the encoder. A stream format contains information used by players to decode a multicast stream, such as the codecs, bit rates, and frame sizes; the format is stored in the header of the stream. If you start encoding before the server initiates the connection with the encoder, the server automatically detects the stream format. However, if you do not want to start encoding first, you can create a stream format file and make it available to the server

70 Page 70 of 100 administrator. The administrator can add the file to the list of supported stream formats on the server publishing point. Stream format files have an.asf extension. Caution Incorrectly editing the registry can severely damage your system. Before making changes to the registry, you should back up any valued data on the computer. Note This topic focuses only on the steps you must perform with the encoder when a Windows Media server is initiating the stream. For detailed information about the steps that must be performed on the Windows Media server, see Windows Media Services Help. Broadcasting content live To enable clients to pull a stream from the encoder To create a stream format file Comparing Windows Media servers and Web servers To increase the maximum number of direct connections To enable clients to pull a stream from the encoder 1. On the toolbar, click Properties, and then click the Output tab. 2. Select the Pull from encoder check box. Enabling clients to pull a stream from the encoder To create a stream format file 1. Set up a session that enables a Windows Media server to pull the stream from the encoder. 2. On the Tools menu, click Generate Stream Format File. 3. In File name, type a name and location for the file, and then click Save. 4. Provide the file to the Windows Media server administrator.

71 Page 71 of 100 Note If you change any of the settings in the encoder configuration, you must create another stream format file and distribute it to the Windows Media server administrator. Enabling clients to pull a stream from the encoder To enable clients to pull a stream from the encoder To increase the maximum number of direct connections 1. In Registry Editor, use the tree view to navigate to the following subkey: HKEY_CLASSES_ROOT\Software\Microsoft\Windows Media Tools\Encoder\MaxClientConnections. 2. Edit the subkey so that it reflects the maximum number of direct connections you want to allow. The maximum possible number is 50. Caution Incorrectly editing the registry can severely damage your system. Before making changes to the registry, you should back up any valued data on the computer. Enabling clients to pull a stream from the encoder Restricting access to a broadcast When you are enabling clients to pull a stream from the encoder, you can allow or deny access to the broadcast based on a static IP address or groups of IP addresses. By default, no clients are restricted from connecting to the broadcast. If you want to specify the clients that can connect, you can add the IP addresses to the allow list. Doing so prevents any unlisted clients from connecting. Or, if you want to prevent a specific client from accessing the broadcast, you can add that client's IP address to the deny list If you make changes to the IP address list while encoding, your changes take effect only for clients

72 Page 72 of 100 that connect after you apply your changes. For example, if you add an IP address to the deny list while that client is connected, the client is not disconnected. However, if the client disconnects and then attempts to reconnect to the same broadcast, it is denied. If it is critical to disconnect a client immediately, you can stop encoding. The following table provides an example of the order in which IP addresses are allowed or denied, depending on the restrictions that you set up. Allow list Deny list Result Empty Empty Allow all IP addresses Empty IP address 1 Deny IP address 1, allow all others IP address 1 Empty Allow IP address 1, deny all others IP address 1 IP address 2 Allow IP address 1, deny all others IP address 1 IP address 1 Deny all IP addresses IP address 1, IP address 2 IP address 1 Allow IP address 2, deny all others When you restrict access to a broadcast by IP address, you can specify both Internet Protocol version 6 (IPv6) and Internet Protocol version 4 (IPv4) addresses. IPv6 is the latest version of the Internet Protocol and was designed to accommodate the rapidly increasing demand for unique IP addresses. IPv6 increases the IP address size from 32 bits to 128 bits to support more levels of addressing hierarchy and a greater number of addressable nodes. For more information about IPv6, see the IPv6 page at the Microsoft Web site. Note You can track which IP addresses are connecting to your broadcasts by enabling logging to a file on the Event log tab of the Monitor panel. Broadcasting content live To grant or deny access to a broadcast To grant or deny access to a broadcast 1. On the Tools menu, click Broadcast Security. 2. Do one of the following: To provide access to an encoding computer, in Allow, click Add. To deny access to an encoding computer, in Deny, click Add. 3. In IP address, type the IP address of the computer for which you want to allow or deny access.

73 Page 73 of 100 -or- In IP mask, type a range of IP addresses for which you want to allow or deny access. 4. Click Add. 5. Repeat steps 3 and 4 until all IP addresses are added. Restricting access to a broadcast Testing your content It is always a good idea to test your content before providing it to users. To run a test, configure a session, and then encode some content. While the content is encoding, use the URL specified on the Connections tab of the Monitor panel to connect the player to the encoder and view the stream. Or, if you are encoding to a file, stop the encoder and then play the output file. If you are planning to distribute your content by using a Windows Media server, you can conduct an end-to-end test. To do so, set up your Windows Media server to connect to the encoder by using the URL specified on the Connections tab of the Monitor panel. As you view the stream, verify the following: You are getting the expected frame rate. Your bandwidth throughput is acceptable. You are receiving an audio and video feed and the quality of each is acceptable. For more information about streaming from a Windows Media server, see Windows Media Services Help. Output options System configuration options

74 Page 74 of 100 This section provides information about options you have for configuring your encoding system, including information about how you can secure the encoding computer and protect the content you are encoding, the steps you can take to achieve optimal system performance, how to run multiple instances of the encoder on a computer, and batch encoding. Windows Media Encoder Security and Windows Media Encoder Achieving optimal system performance Best practices for compression settings Running multiple encoders on one computer Batch encoding Security and Windows Media Encoder Security considerations for Windows Media Encoder involve both security for the encoding computer and protecting the content you are encoding. To learn more about security issues relating to the encoding computer, refer to the security section of the operating system documentation. To protect your content, you can protect it with digital rights management (DRM) during encoding. If you are broadcasting, you can restrict access to the encoder by IP address. In addition, you can use Internet Protocol Security (IPSec), an industry-defined set of standards that verifies, authenticates, and optionally encrypts data at the IP packet level. For more information about IPSec, see Windows Help and Support. If you are encoding content for broadcast from a Windows Media server, see the Windows Media Services Help for information about security and the Windows Media server. System configuration options Using digital rights management to protect content Restricting access to a broadcast Achieving optimal system performance

75 Page 75 of 100 To achieve optimal system performance: Use a computer with fast or multiple processors. Because high-quality encoding requires more computing power, use a computer with a fast processor or multiple processors, especially for live events. Windows Media Encoder can use up to two processors for audio, and up to four for video to efficiently distribute the encoding load. If you are using the Windows Media Video 9 codec, you can also adjust performance settings to ensure encoding success. As a general rule, if you find that you continually reach or exceed 80 percent of the CPU load (as indicated on the General tab of the Monitor panel), you may want to consider upgrading your computer. Use supported audio and video cards. For a complete list of supported cards, see the Microsoft Web site. Use Microsoft Windows XP Professional. Windows XP Professional takes full advantage of a multiprocessor computer by automatically spawning separate threads to enable processes to run different parts of their programs on different processors simultaneously. This parsing of the work enables you to perform high-end encoding tasks without maximizing your CPU usage. Check your network bandwidth. It is rare that you will achieve 100 percent throughput when sending content over a network. For optimal results, ensure that your network can accommodate the aggregate bandwidth required by your broadcast session plus the overhead for HTTP. Use a high-performance hard disk. For archiving or file conversion, use a high-performance hard disk, such as a small computer system interface (SCSI) hard disk with 15,000 rotations per minute. Using a high-performance hard disk can help to offload performance requirements from the main CPU, freeing up more processing power for encoding. In addition, it is useful to use the hard disk only for encoding purposes. Keep the encoder on a dedicated computer. If you are streaming content from a server running Windows Media Services, it is recommended that you run the encoder on a separate computer from the Windows Media server. Turn off video preview and postview. The Input and Output areas in the main encoder window show you what your content looks like before and after it is encoded. Turning off these displays improves encoding performance. Or, to achieve a minor performance improvement, you can reduce the views. Store captured content temporarily. If you are encoding to a file while sourcing from devices, store the content to a hard disk temporarily. In addition, use a different hard disk than the one dedicated to encoding. System configuration options Adjusting encoder performance settings To turn off or decrease video preview Improving performance when encoding screens To store captured content temporarily To turn off or decrease video preview

76 Page 76 of On the View menu, click Video Panel. 2. To turn off video preview, in Display, click Output. -or- To decrease the size of the preview, in Zoom, click 50%. Achieving optimal system performance Adjusting encoder performance settings Encoding is a CPU-intensive process. If you continually exceed the capabilities of your encoding computer, you can review the most recent hardware and software requirements to determine if you should upgrade to a more powerful computer. If upgrading is not feasible, however, you can adjust encoder performance settings to ensure success with encoding. (The settings only apply to sessions in which you use the Windows Media Video 9 codec.) Your performance choices are whether to place emphasis on better performance or on better quality. A better performance setting corresponds to lower CPU usage; a better quality setting corresponds to higher usage of the CPU power. Keep the following in mind when choosing performance settings: If the amount of time needed to encode is not important, you can use the better quality setting. This is most appropriate for a scenario in which you are both sourcing from a file and encoding to a file. The encoder takes as much time as needed to encode. If it is important that encoding keep pace with capturing, then use the better performance setting. This is appropriate for a scenario in which you are broadcasting, or for a scenario in which you are sourcing from devices and encoding to a file. For the encode-to-file scenario, you can also enable temporary storage for the captured content. With temporary storage, captured data is stored temporarily if the encoding process falls behind the capturing process. For all of the scenarios, you may want to try different performance settings to find the balance between quality and performance for your computer. Keep in mind that other factors affect CPU usage during encoding. For example, session settings such as frame rate, bit rate, and frame size affect how much work the CPU needs to perform encoding. In addition, other programs running on the encoding computer leave less processing power for the encoder. Achieving optimal system performance Hardware and software requirements Encoding or archiving a broadcast to a file To adjust performance settings To store captured content temporarily

77 Page 77 of 100 To adjust performance settings 1. On the Tools menu, click Options, and then click the Performance tab. 2. In When broadcasting, move the slider to the desired setting. 3. In When encoding to a file, move the slider to the desired setting. Adjusting encoder performance settings Best practices for compression settings There is a balance between a number of compression settings. The encoder includes many predefined destination, video, and audio settings (profiles) that have already taken this balance into consideration. You can easily set up an encoding session using a predefined profile. However, if you want to customize the settings, then the following paragraphs provide information about the settings, including some of the tradeoffs to consider. Buffer. A larger buffer can accommodate a better image quality, but the user must wait longer for the video to start, as a player waits to play until its buffer is filled. Typically, the buffer delay matches the time, in seconds, of the buffer size set in the encoder. However, if you plan to stream from a Windows Media server, you can set a larger buffer size in the encoder. A feature in Windows Media Services, called Fast Start, enables a player to fill its buffer faster than real time, assuming there is sufficient bandwidth. This means that the initial buffer delay may be much shorter. For example, when a user attempts to play back 56-Kbps encoded content on a DSL or cable modem, the start-up delay may be only a second or two, even if the buffer size set during encoding was much longer. For more information about Fast Start, see Windows Media Services Help. If you have set up a session that uses peak bit rate-based VBR encoding for audio, the peak buffer size for audio should be lower than the buffer size for video (if you are using CBR encoding for video) or peak buffer size for video (if you are using peak bit rate-based encoding for video). Bit rate. A higher bit rate achieves a better image quality. If the bit rate setting is too low, the codec will drop frames to produce a higher quality image, although this may not be visible to the viewer. (Note that if you are encoding low-motion video, the actual bit rate may be significantly lower than the expected bit rate.)

78 Page 78 of 100 Frame rate. There is a tradeoff between image quality and frame rate, in that as the image quality increases, the frame rate decreases. If maintaining the frame rate is more important, you can decrease the image quality setting. Image quality (smoothness). You can adjust the image quality to be smoother or more clear. Increasing the clarity can affect the frame rate, depending on the video. For example, if your video contains a lot of motion, increasing the clarity may decrease the frames rate. In addition, increasing the clarity results in a higher bit rate requirement and may also necessitate increasing the buffer size. Frame size. The larger the frame size, the higher the bit rate requirement. Key frames. If you use a longer key frame distance, additional key frames are inserted when necessary; for example, when a scene changes. For low motion content, a setting of 20 seconds is typically appropriate. For higher bit rate content, you should lower the key frame distance. Codecs. Use the appropriate codec for the session. For example, when your audio source is voice or primarily voice, use the Windows Media Audio 9 Voice codec. For a screen capture session, use the Windows Media Video 9 Screen codec. Two-pass encoding. You will typically achieve higher quality with two-pass encoding, because the encoder has the opportunity to analyze the content during the first pass. Video resizing. Set up the output frame size to be the same as the input frame size. Do not use the encoder to resize the source video. System configuration options Achieving optimal system performance Optimizing audio for voice Improving performance when encoding screens Understanding codecs About one- or two-pass encoding To match the frame size of the source video Running multiple encoders on one computer You can run multiple instances of Windows Media Encoder on a single computer provided the computer is powerful enough to support them. By running multiple instances of the encoder, you can: Simultaneously broadcast separate streams at different bit rates. Simultaneously convert multiple files to Windows Media Format. Use a multiple-port device as your source, and then stream the encoded content from each port to different locations. If you decide to run multiple encoders on one computer, keep in mind that input devices can be used by only one process at a time, so you might want to install several audio and video capture cards. For optimal performance, use a computer with two or more processors.

79 Page 79 of 100 System configuration options Batch encoding If you want to encode multiple audio and video files, you can use Windows Media Encoding Script, which is included with Windows Media Encoder. Or, you can automate the encoder for batch encoding by using a script and Windows Script Host. For more information about Windows Script Host and batch encoding, see the Windows Media Encoder 9 Series SDK. System configuration options About the encoder utilities Frequently asked questions and troubleshooting For up-to-date information about working with the encoder, see the Windows Media page at the Microsoft Web site. Technical support options The services and prices listed in the following table are available in the United States only. Support

80 Page 80 of 100 outside the United States may vary, the worldwide Web site listed in the table for regional contact details. Microsoft's support services are subject to Microsoft's then-current prices, terms, and conditions, which are subject to change without notice. Item Online support information Description For general questions, visit the Microsoft Web site, or in Canada, visit the Microsoft Web site. For articles targeted at specific issues, visit the Microsoft Knowledge Base. To work with a Microsoft Support Professional over the Internet, you can submit an online request form at the Microsoft Web site. For the general support policy, visit the options page at the Microsoft Web site. Phone support For Paid Assisted Support, call (800) in the United States or (800) in Canada. You can also call (425) in the United States, or (905) in Canada (toll charges may apply). TTY service Microsoft text telephone (TTY/TDD) services are available at (425) in Washington state or (800) in the United States. In Canada, call (905) Worldwide Support outside the United States and Canada may vary. For regional contact details, visit the international page at the Microsoft Web site. If there is no Microsoft subsidiary office in your country or region, please contact the establishment from which you obtained Windows Media Encoder. Accessibility for people with disabilities Microsoft is committed to making its products and services easier for everyone to use. The following topics provide information about the features, products, and services that make Microsoft Windows Media Encoder more accessible for people with disabilities: Accessibility features in Windows Media Encoder Accessibility features in Windows Media Encoder Help Accessible products and services from Microsoft Note The information in this section applies only to users who license Microsoft products in the United States. If you obtained this product outside the United States, your package contains a subsidiary information card listing Microsoft support services telephone numbers and addresses. You can contact your subsidiary to find out whether the products and services

81 Page 81 of 100 described in this section are available in your area. Accessibility information is available in other select languages, including Japanese and French. For more information, see the Microsoft Web site. Accessibility features in Windows Media Encoder In addition to accessibility features and utilities in Windows, the following feature makes Windows Media Encoder more accessible for people with disabilities: Using keyboard shortcuts Accessibility for people with disabilities Using keyboard shortcuts By using the following keyboard shortcuts in Windows Media Encoder, you can quickly accomplish many common tasks. To do this Display context-sensitive Help. Move forward through the options on a dialog box or property sheet. Move backward through the options on a dialog box or property sheet. Scroll up one item in a spin box or drop-down list. Scroll down one item in a spin box or dropdown list. Use this keyboard shortcut F1 TAB SHIFT+TAB UP ARROW DOWN ARROW

82 Page 82 of 100 Scroll forward through tabs. Scroll backward through tabs. Refresh the current dialog box or control (refresh plug-in list, refresh playlist view). Dismiss property sheet or dialog box or cancel out of a wizard. Carry out the command for the active option or button Cut the selected items and copy them to the Clipboard. Copy the selected items to the Clipboard. Paste the contents of the Clipboard at the selected location. Display or hide the Session Properties panel. Close current window. Display shortcut menu. Select or clear the selection of an item. Display context menu. Switch to High Contrast mode. RIGHT ARROW LEFT ARROW F5 or CTRL+R ESC ENTER CTRL+X CTRL+C CTRL+V ALT+ENTER ALT+F4 SHIFT+F10 SPACEBAR Application Key LEFT ALT+LEFT SHIFT+PRINT SCREEN Accessibility for people with disabilities Accessibility features in Windows Media Encoder Help Windows Media Encoder Help includes features that make it accessible to a wider range of users, including those who have limited dexterity, low vision, or other disabilities. In addition, Windows Media Encoder Help is available on the Web at the Microsoft Web site. Accessibility for people with disabilities

83 Page 83 of 100 Keyboard shortcuts for using the Help window By using the following keyboard shortcuts in Help, you can quickly accomplish many common tasks. To do this Display the Help window. Switch between the Help topic and the Contents, Search, and Index tabs. Select the next hidden text or hyperlink. Select the previous hidden text or hyperlink. Perform the action for the selected Show All, Hide All, hidden text, or hyperlink. Display the Options menu to access any Help toolbar command. Hide or show the pane containing the Contents, Search, and Index tabs. Display the previously viewed topic Display the next topic in a previously displayed sequence of topics. Return to the specified home page. Stop the Help window from opening a Help topic (useful if you want to stop a Web page from downloading). Open the Internet Options dialog box for Microsoft Internet Explorer, where you can change accessibility settings. Refresh the topic (useful if you have linked to a Web page). Print all topics in a book or a selected topic only. Close the Help window. Use this keyboard shortcut F1 F6 TAB SHIFT+TAB ENTER ALT+O ALT+O, and then press T ALT+O, and then press B ALT+O, and then press F ALT+O, and then press H ALT+O, and then press S ALT+O, and then press I ALT+O, and then press R ALT+O, and then press P ALT+F4

84 Page 84 of 100 Accessibility features in Windows Media Encoder Help To change the appearance of a Help topic 1. To customize the colors, font styles, and font sizes used in Help, open the Help window. 2. Click Options, and then click Internet Options. 3. On the General tab, click Accessibility. Select Ignore colors specified on Web pages, Ignore font styles specified on Web pages, and Ignore font sizes specified on Web pages. You also can choose to use the settings specified in your own style sheet. 4. To change the colors used in Help, see To change the color of the background or text in Help. To change the font, see To change the font in Help. Accessibility features in Windows Media Encoder Help To change the color of the background or text in Help 1. Open the Help window. 2. Click Options, and then click Internet Options. 3. On the General tab, click Accessibility. Then select Ignore colors specified on Web pages. You also can choose to use the settings specified in your own style sheet. 4. To customize the colors used in Help, on the General tab, click Colors. Clear the Use Windows Colors check box, and then select the font and background colors you want to use. Note If you change the background color of the Help topics in the Help window, the change also affects the background color when you view a Web page in Microsoft Internet Explorer. Accessibility features in Windows Media Encoder Help

85 Page 85 of 100 To change the font in Help 1. Open the Help window. 2. Click Options, and then click Internet Options. 3. On the General tab, click Accessibility. To use the same settings as those used in your instance of Microsoft Internet Explorer, select Ignore font styles specified on Web pages and Ignore font sizes specified on Web pages. You also can choose to use the settings specified in your own style sheet. 4. To customize the font style used in Help, on the General tab, click Fonts, and then click the font style you want. Note If you change the font of the Help topics in the Help window, the change also affects the font when you view a Web page in Microsoft Internet Explorer. Accessibility features in Windows Media Encoder Help Accessible products and services from Microsoft The following topics provide information about the features, products, and services that make this Microsoft product more accessible for people with disabilities: Accessibility in Microsoft Windows Adjusting Microsoft products for people with accessibility needs Free step-by-step tutorials Microsoft documentation in alternative formats Assistive technology for Windows Customer service for people who are deaf or hard-of-hearing Getting more accessibility information The information in this section applies only to users who license Microsoft products in the United States. If you obtained this product outside the United States, your package contains a subsidiary information card listing Microsoft support services telephone numbers and addresses. You can contact your subsidiary to find out whether the type of products and services described in this section are available in your area. Accessibility is available in other select languages, including Japanese and French. For more information, see the Microsoft Web site.

86 Page 86 of 100 Accessibility for people with disabilities Accessibility in Microsoft Windows Many accessibility features have been built into Microsoft Windows, starting with the introduction of Windows 95. These features are useful for individuals who have difficulty typing or using a mouse, are blind or have low vision, or who are deaf or hard-of-hearing. The features can be installed during setup. For more information about the various accessibility features of Microsoft Products, such as Microsoft Windows XP Professional, Windows XP Home Edition, Windows Millennium Edition, Windows 2000, Windows 98, and Windows 95, see the Microsoft Web site. Accessible products and services from Microsoft Adjusting Microsoft products for people with accessibility needs Accessibility options and features are built into many Microsoft products, including the Windows operating system. Accessibility options and features are useful for individuals who have difficulty typing or using a mouse, are blind or have low vision, or who are deaf or hard-of-hearing. Accessible products and services from Microsoft

87 Page 87 of 100 Free step-by-step tutorials Microsoft offers a series of step-by-step tutorials to help you learn how to adjust the accessibility options and settings on your computer. The tutorials provide detailed procedures on how to adjust options, features, and settings to meet the needs of people with disabilities and accessibility needs. This information is presented in a side-by-side format so that you can see at a glance how to use the mouse, the keyboard, or a combination of both. To find step-by-step tutorials for Microsoft products, see the Accessibility section of the Microsoft Web site. Accessible products and services from Microsoft Microsoft documentation in alternative formats In addition to the standard formats, documentation for many Microsoft products is available in other formats to make it more accessible. If you have difficulty reading or handling printed materials, you can obtain the documentation for many Microsoft products in other, more accessible formats. You can download many of these books from the Microsoft Web site. Microsoft produces an index of accessible documentation on the Accessibility section of the Microsoft Web site. In addition, you can obtain additional Microsoft publications from Recording for the Blind & Dyslexic, Inc. These documents are distributed to registered, eligible members of their distribution service on audiocassettes or on floppy disks. The collection contains more than 80,000 titles, including Microsoft product documentation and books from Microsoft Press. For information about eligibility and availability of Microsoft product documentation and books from Microsoft Press, contact: Recording for the Blind & Dyslexic, Inc. 20 Roszel Road Princeton, NJ Phone from within the United States: (800) Phone from outside the United States and Canada: (609)

88 Page 88 of 100 Fax: (609) Recording for the Blind & Dyslexic Web site Web addresses can change, so you might be unable to connect to the Web site or sites mentioned here. Accessible products and services from Microsoft Assistive technology for Windows A wide variety of accessibility aids, or assistive technology products, are available to make computers easier to use for people with disabilities. Microsoft provides a searchable catalog of accessibility aids that run on Microsoft Windows operating systems at the Accessibility section of the Microsoft Web site. Among the different types of products available for the MS-DOS, Windows, and Windows NT operating systems are: Programs that enlarge the information displayed or alter the color of information on the screen for people with visual impairments. Programs that describe information on the screen in Braille or synthesized speech for people who are blind or have difficulty reading. Hardware and software utilities that modify the behavior of the mouse and keyboard. Programs that enable people to type by using a mouse or their voice. Word or phrase prediction software that enable users to type more quickly and with fewer keystrokes. Alternative input devices, such as single switch or puff-and-sip devices, for people who cannot use a mouse or a keyboard. Upgrading If you use assistive technology, before you upgrade either your software or hardware, be sure to contact your assistive technology vendor to check compatibility with products on your computer. Your assistive technology vendor can also help you learn how to adjust your settings to optimize compatibility with your version of Windows or other Microsoft products.

89 Page 89 of 100 Customer service for people who are deaf or hard-of-hearing If you are deaf or hard-of-hearing, complete access to Microsoft product and customer services is available through a text telephone (TTY/TDD) service. Customer service You can contact Microsoft Sales Information Center on a text telephone by dialing (800) between 6:30 AM and 5:30 PM Pacific time, Monday through Friday, excluding holidays. Technical assistance For technical assistance in the United States, you can contact Microsoft Product Support Services on a text telephone at (800) between 6:00 AM and 6:00 PM Pacific time, Monday through Friday, excluding holidays. In Canada, dial (905) between 8:00 AM and 8:00 PM Eastern time, Monday through Friday, excluding holidays. Microsoft support services are subject to the prices, terms, and conditions in place at the time the service is used. Accessible products and services from Microsoft Getting more accessibility information The Accessibility section of the Microsoft Web site provides information about accessible technology to help improve the lives of people with disabilities by making computers a positive force in employment, education, and recreation. The information on this site benefits people with disabilities and their friends and family members, people in outreach organizations, educators, and advocates. A free monthly newsletter is offered through to help you keep up to date with accessibility topics about Microsoft products at the Accessibility section of the Microsoft Web site. Accessible products and services from Microsoft

90 Page 90 of 100 Glossary To find a term in the glossary, click the letter of the alphabet that is the first letter in the term you want to look up. You can also read glossary terms within the text of Help by clicking the underlined glossary term links. After you click a glossary link, the glossary term and definition appear in a pop-up window. To close the window, click anywhere on the screen. P.prx The file name extension of a profile. Back to Top Symbols.weu The file name extension of a configuration file used by Windows Media Encoding Script..wma The file name extension of an audio file in Windows Media Format. The audio content of the file is encoded with the Windows Media Audio codec..wme The file name extension for a Windows Media Encoder session file..wmv The file name extension of a video file in Windows Media Format. Back to Top A A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

91 Page 91 of 100 announcement A Windows Media metafile that gives a player the information needed to receive content. Announcement files contain Extensible Markup Language (XML) scripts. aspect ratio The ratio of the width of an image to its height. Audio Video Interleaved (AVI) A multimedia file format for storing sound and moving pictures in RIFF format. AVI See definition for: Audio Video Interleaved (AVI) Back to Top B bandwidth A network's capacity for transferring an amount of data in a given time. bit rate The number of bits transferred per second. Back to Top C caption Text that accompanies images or videos, either as a supplemental description or a transcript of spoken words. CBR See definition for: constant bit rate (CBR) codec An abbreviation for compressor/decompressor. Software or hardware used to compress and decompress digital media. compression A process for removing redundant data from a digital media file or stream to reduce its size or the bandwidth used.

92 Page 92 of 100 configuration file A text file used by Windows Media Encoding Script that specifies the content to be encoded and the command-line options to be invoked. constant bit rate (CBR) A characteristic of a data stream in which the bit rate remains nearly uniform for the duration of the stream. See also: variable bit rate (VBR) content Audio, video, images, text, or any other information that is contained in a digital media file or stream. Back to Top D deinterlace To combine the interlaced fields in a video frame so that, during playback, the lines of the video frame are painted sequentially. See also: interlace delta frame A video frame that contains only the changes from the previous frame. In contrast, a key frame contains all the data necessary to construct that frame. dynamic range The difference (in decibels) between the quietest and loudest sounds in a single piece of audio content. Back to Top E encode To convert audio and video content to a specified digital format. Back to Top F frame rate

93 Page 93 of 100 The number of video frames displayed per second. Higher frame rates generally produce smoother movement in the picture. Back to Top H header A part of the file structure that contains information required by an application to decompress and render the content. The header in a protected file also contains information required to get a license. Back to Top I IEEE 1394 See definition for: Institute of Electrical and Electronics Engineers (IEEE) 1394 Institute of Electrical and Electronics Engineers (IEEE) 1394 A high-speed serial bus standard that provides enhanced computer connectivity for a wide range of devices, including consumer electronics audio/video (A/V) appliances, storage peripherals, other computers, and portable devices. intelligent streaming A type of streaming that detects network conditions and adjusts the properties of a video or audio stream to maximize quality. interlace To display a video frame in two fields. One field contains the even lines of the frame, the other field contains the odd lines. During playback, the lines in one field are displayed first, then the lines in the second field are displayed. Internet Protocol version 6 (IPv6) A revised version of the Internet Protocol (IP) designed to address growth on the Internet. Improvements include a 128 bit IP address size, expanded routing capabilities, and support for authentication and privacy. inverse telecine The process that removes the frames that were added when 24-fps film was converted to 30-fps video. IPv6 See definition for: Internet Protocol version 6 (IPv6)

94 Page 94 of 100 Back to Top K key frame A video frame containing all the data needed to construct an image without reference to previous frames. See also: delta frame Back to Top L latency The delay that occurs while data is processed or delivered. letterbox A video display format in which black bars appear above and below the video image while it is played. The letterbox format maintains the original aspect ratio of an image when it is displayed in a window with a different aspect ratio. license Data attached to protected content that describes how the content can be used. loop To repeat a stream continuously. lossless compression A process for compressing data in which information is arranged in a more concise form and restored to its original state upon decompression. lossy compression A process for compressing data in which information deemed unnecessary is removed and cannot be recovered upon decompression. Typically used with audio and visual data in which a slight degradation of quality is acceptable. Back to Top M marker A text string that is associated with a designated time in Windows Media-based content. Markers often denote convenient points to begin playback, such as the start of a new scene.

95 Page 95 of 100 MBR See definition for: multiple bit rate (MBR) metadata Data about data. Title, subject, author, and size are examples of a file's metadata. multicast A content delivery method in which a single stream is transmitted from a media server to multiple clients. The clients have no connection with the server. Instead, the server sends a single copy of the stream across the network to multicast-enabled routers, which replicate the data. Clients can then receive the stream by monitoring a specific multicast IP address and port. multichannel audio An audio reproduction system that processes several, typically more than two, channels of sound. For example, 5.1 multichannel audio refers to a surround sound system in which there are five primary channels and a subwoofer channel. multiple bit rate (MBR) A characteristic of a data stream in which the same content is encoded at several different bit rates in order to optimize content delivery. Back to Top N National Television Standards Committee (NTSC) The dominant television standard in the United States and Japan. NTSC delivers 30 interlaced frames per second at 525 lines of resolution. NTSC See definition for: National Television Standards Committee (NTSC) Back to Top O one-pass encoding An encoding method in which content is analyzed and compressed in the same pass through the encoder. See also: two-pass encoding PAL

96 Page 96 of 100 See definition for: Phase Alternating Line (PAL) PCM See definition for: pulse code modulation (PCM) Phase Alternating Line (PAL) The dominant television standard in Europe and China. PAL delivers 25 interlaced frames per second at 625 lines of resolution. pixel format The size and arrangement of pixel color components. The format is specified by the total number of bits used per pixel and the number of bits used to store the red, green, blue, and alpha components of the color of the pixel. postroll To extend the amount of encoded video by a specified number of frames. preroll To capture or play a number of video frames or a portion of audio data before encoding or rendering begins, in order to allow the source device to stabilize. Also used as a noun to describe the portion of the data to be prerolled. profile A group of settings that match content type and bit rate with appropriate audio and video codecs. Profile Editor A tool provided with Windows Media Encoder that creates and edits the encoding profiles. See also: profile publishing point An organized memory location that translates a client request for content into the physical path on the server hosting the content. A publishing point essentially acts as a redirector. pull To deliver data to a client only upon client request. pulse code modulation (PCM) A technique for digitizing audio into an uncompressed format by assigning a value to the amplitude of the signal at fixed intervals. push

97 Page 97 of 100 To deliver data to a client without a client request for the data. Back to Top R RGB A color model that describes color information in terms of the red (R), green (G), and blue (B) intensities that make up the color. Back to Top S sampling The process of measuring the amplitude of an analog signal at regular intervals for the purpose of converting the signal into a digital format. sampling rate The frequency of sampling. The higher the sampling rate (that is, the more samples taken per unit of time), the more closely the digitized result resembles the original. script commands Named data that is associated with a designated time in Windows Media-based content. The data can be used by players to perform a specific action such as displaying a Web page. source Audio and video content that can be captured and encoded from devices installed on your computer or from a file. stream Digital media that is in the process of being delivered in a continuous flow across a network. stream format Information about the properties of a stream, such as the codecs used, frame rate, and frame size. A player uses stream format information to decode a stream. stream format file A file used by a player to decode a multicast stream. See also: stream format Back to Top

98 Page 98 of 100 T telecine The film-to-video conversion system that adds frames to video to compensate for the differences in frame rates between film and video. time code A digital signal applied to a stream. The signal assigns a number to every frame of video, representing hours, minutes, seconds, and frames. two-pass encoding An encoding method in which content is analyzed in one pass through the encoder, after which compression is applied in the second pass. See also one-pass encoding. Back to Top U UDP See definition for: User Datagram Protocol (UDP) UNC See definition for: Universal Naming Convention (UNC) unicast A method used by media servers for providing content to connected clients in which each client receives a discrete stream. No other client has access to that stream. Universal Naming Convention (UNC) The full name of a resource on a network. It conforms to the \\servername\sharename syntax, where servername is the name of the server and sharename is the name of the shared resource. UNC names of directories or files can also include the directory path under the share name, with the following syntax: \\servername\sharename\directory\filename. User Datagram Protocol (UDP) A connectionless transport protocol in the TCP/IP protocol stack that is used in cases where some packet loss is acceptable, for example, with digital media streams. Back to Top V variable bit rate (VBR)

99 Page 99 of 100 A characteristic of a data stream in which the bit rate fluctuates, depending upon the complexity of the data. VBR See definition for: variable bit rate (VBR) Back to Top W Windows Media Audio codec A codec used to compress and decompress audio streams. Windows Media file A file containing audio, video, or script data that is stored in Windows Media Format. Depending on their content and purpose, Windows Media files use a variety of file name extensions, such as:.wma,.wme,.wms,.wmv,.wmx,.wmz, or.wvx. Windows Media Format The format used by Microsoft Windows Media Technologies (or a third-party product that incorporates a licensed Windows Media technology) to author, store, edit, distribute, stream, or play timeline-based content. Windows Media metafile In Windows Media Technologies, a file that provides information about Windows Media files and their presentation. File name extensions for Windows Media metafiles include.asx,.wax,.wvx,.wmx, and.nsc. Windows Media Screen codec A codec used to compress and decompress sequences of screen images. Windows Media Video codec A codec used to compress and decompress video streams. Back to Top Y YUV A color model that describes color information in terms of its brightness (luminance, or Y), and color (chrominance, or U and V). Back to Top

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