Adding High-Quality Audio to Web and App Experiences
Contents Adding High-Quality Audio to Web and App Experiences Contributor: Matt Gillespie 2 2 Immersive Dolby Audio for the Web, PCs, and Tablets 4 Windows 10 Delivers Professional-Quality Dolby Audio 4 6 6 State-of-the-Art Dolby Audio Comes to Web Apps
Immersive Dolby Audio for the Web, PCs, and Tablets By Matt Gillespie D olby Digital Plus is now built into Microsoft Windows 10 and the new Microsoft Edge browser, delivering robust, multidimensional sound to mainstream user experiences. Games, online content, and voice-communication apps just got richer. Loud and clear sound is now available even in challenging circumstances, such as noisy environments, low-quality speakers, and limited bandwidth. Moreover, these dramatic improvements to audio experiences are not reserved for a rarified group of users with high-end gear. Dolby Digital Plus explicitly targets the full range of common business and consumer usages and equipment. Over the past decade or so, high-definition video displays have become the norm, from the ever-growing flat-screen TVs in our living rooms to the advanced small displays on our smartphones. At the same time, audio quality has remained a relative afterthought. It s common when buying a PC, for example, to invest in multiple, large flatscreen displays but to accept the low-quality two-channel speakers that come at low or no cost with the machine. The lower attention paid to audio equipment largely reflects the common reality of low fidelity in the audio streams themselves. In short, end users have been forced to accept low-definition sound, even as they have come to expect high-definition visuals. With the mainstream adoption of Dolby Digital Plus for the web, PCs, and tablets, that disparity is beginning to disappear. Audio Innovation, for Parity with HD Video The chief limitation in delivering high-fidelity audio has historically been the tradeoff between quality and data size. To achieve suitable compression ratios especially for streaming implementations developers have typically used lossy codecs such as MP3 and AAC. While this approach has achieved the desired compression ratios, it tends to provide an underwhelming audio experience. The efficiency of Dolby Digital Plus achieves high compression while preserving excellent sound quality. Crystal-clear playback is available in Windows applications for Windows 10 x86 PCs and Windows 10 tablets down to nine inches, as well as for online content using the Edge browser. In addition to outstanding clarity, Dolby Digital Plus delivers better dialogue and dyanmic range. 2 Back to Contents
Enveloping Users in Outstanding Audio Experiences Dolby Digital Plus, also known as Enhanced AC-3, is built to deliver next-generation audio, including in mainstream consumer usage. In place of the two-channel stereo sound that is common in earlier client and online applications, Dolby Digital Plus supports up to 8 audio channels. It also features very low latency, making it well suited for highfidelity sound reproduction in streaming implementations and voice communication. Demanding usages such as games and media showcase the capabilities of Dolby Digital Plus, with sound that provides immersive, lifelike audio experiences. In addition, on the high-end headsets that have become increasingly popular particularly among gamers surround provides similarly naturalistic effects. In either case, audio on a PC or tablet now supports professional production values that evoke the audio experience in a movie theater or on Blu-ray. Integrates into Existing Development Processes As an alternative to desktop transcoding, Microsoft Azure Media Services and Encoding.com provide a cloudbased option for encoding Dolby Digital Plus audio and video content. After generating surround-sound files on the desktop and exporting them as WAV or AIFF files, developers can programmatically encode those files to create Dolby Digital Plus content using the Microsoft Azure Media Encoder. Pricing on a per-gigabyte basis for this transcoding (potentially using a free trial of Azure itself) makes it a flexible, cost-effective approach. Conclusion With a low threshold for entry by developers, in terms of both effort and cost, Dolby Digital Plus brings highdefinition audio to mainstream web and Windows applications. As the adoption of these improvements proceeds, older sound formats will reach legacy status. Better sound experiences are emerging as the new normal. Experience the difference for yourself at: www.dolby.com/ us/en/technologies/dolby-digital-plus.html To streamline adoption by the development community, Dolby Digital Plus is designed to be a drop-in addition to existing workflows. Built-in support within Windows 10 and the Microsoft Edge browser allow for Dolby Digital Plus to be utilized just like any other codec, without requiring specialized coding techniques, beyond simple feature detection for browsers, which can be handled either in HTML or JavaScript. This approach also allows the web app simply to fall back to a stereo-encoded audio stream if the Dolby Digital Plus codec is unavailable on the target machine. Dolby Digital Plus is well supported in popular, widely used toolchains. The current versions of Adobe Premiere Pro and Adobe Audition, for example, natively support mixing sound for up to 7.1 surround playback, without additional plug-ins. A simple export process from the main user interface generates H.264 or MPEG2 Blu-ray content formats encoded with Dolby Digital Plus audio. Likewise, Avid Pro Tools and Audacity allow for the generation of 5.1 or 7.1 surround audio as simply as other file formats. 3 Back to Contents
Windows 10 Delivers Professional-Quality Dolby Audio By Matt Gillespie With support for Dolby Digital Plus right out of the box, Microsoft Windows 10 changes the game for audio in mainstream applications. As the platform of choice for many new PCs and tablets, and a free upgrade for existing Windows 7, 8, and 8.1 users, Windows 10 has remarkable reach. Developers can target that user base directly through Windows content and software, including desktop and Windows Store apps. Highfidelity audio using Dolby Digital Plus provides a valueadd and a competitive differentiator. Accessed programmatically like any other codec, Dolby Digital Plus provides superior audio clarity and detail. In contrast to older sound formats that are limited to twochannel stereo, Dolby Digital Plus offers as many as 8 channels, as well as immersive 5.1 or 7.1 surround sound on capable home theater systems. For playback on headphones or mainstream PC speakers, Dolby Digital Plus delivers a similarly engaging experience. In any playback scenario, Dolby Digital Plus provides premium-quality sound that takes optimal advantage of both the audio source and the listening equipment. Games, media, and other entertainment can bring audio to users with realism that is reminiscent of a modern movie theater. Other types of software -- for example, Enterprise, Productivity and business software -- can provide improved audio that enhances the overall user experience and product quality. Farewell to Low-Quality Sound The past several years have seen a switch in attention by software architects and designers from adding features to enhancing the user experience. Applications have become more intuitive, and natural user interfaces have emerged, incorporating everything from multi-touch to eye tracking and speech recognition. High-definition video has become nearly a baseline requirement for many types of content. Even so, the evolution of audio has lagged. Two-channel stereo sound has remained the norm, even for highbudget games that employ professional voice talent, composers, and sound designers. Bulky codecs with lossy formats such as MP3 and AAC have lingered, compromising audio quality in spite of other advances. Next-Generation Dolby Audio, Integrated at the OS Level With Microsoft licensing Dolby Digital Plus for Windows 10, sound quality at the OS level (and within the new Microsoft Edge browser) has reached a tipping point. 4 Back to Contents
Professional audio is now a standard offering for all types of content playback on mainstream Windows 10-based desktop x86 PCs, laptops, and tablets down to nine inches in size. Because the Dolby Digital Plus codec is built into Windows 10, it does not require enabling effort by end users. This factor streamlines adoption by software customers, in both the consumer and business segments. Moreover, very little effort is required by Windows 10 universal app developers. They need only encode audio content to support Dolby Digital Plus, and Windows 10 will automatically do the rest. Further adding to simplicity for the developer community, popular tools such as Adobe Premiere Pro, Avid Pro Tools, Audacity, Azure Media Services, and Encoding.com provide streamlined workflows to generate Dolby Digital Plus audio. Jaw-Dropping Audio for Entertainment and Games Video, music, and game applications are perhaps the foremost showcases for user experiences that are enriched with superior sound. In this type of use case, Dolby Digital Plus audio envelopes the user in an immersive soundscape, elevating the overall experience with superior realism and fidelity. These enhancements have specific capabilities for portable devices, which tend to be particularly constrained and create added challenges in terms of audio quality. Dolby Digital Plus supports dynamic range control to optimize audio for built-in speakers and headphones. Using this feature, Windows 10 optimizes playback, overcoming limitations in terms of clarity and loudness that users would otherwise experience. By enabling a fuller audio experience, Dolby Digital Plus enhances the value of investments made by creators of applications and other content. It is common for production houses to invest heavily in the creation of high-quality audio and then to down-sample it before delivery of a computer game, for example. This practice represents a common requirement to make sacrifices in quality to meet the requirements of data size. Sound as Nature Intended for General-Purpose Apps Outside the entertainment sphere, audio can also play a pivotal role in the quality of the user experience. For example, sound quality in business-class voicecommunication implementations is notoriously poor. Often, participants must struggle to understand what is being said, focusing on the medium itself, rather than the content it delivers. Obviously, cases such as this stand to benefit from better audio clarity. Dolby Digital Plus content includes a dialogue normalization parameter, a capability that overcomes issues in scenarios where dialogue needs to be heard. Making spoken content more understandable has value across a wide variety of media, such as computer-based training, as well as marketing videos and webcasts used either online or at live events. Higher-fidelity voice content can even help facilitate emerging usage models based on voice recognition, such as knowledge bases generated from customer interactions. Conclusion With Dolby Digital Plus now an integral part of Windows 10, audio has reached parity in terms of quality with HD video, across the spectrum of Windows applications. Outstanding clarity and immersive experiences are now available for content that ranges from games and multimedia to voice communications and other business usages. Professional-quality audio, including surround and virtual surround sound, is now becoming a standard capability for Windows PCs and tablets. Experience the difference for yourself at: www.dolby. com/us/en/technologies/dolby-digital-plus.html 5 Back to Contents
State-of-the-Art Dolby Audio Comes to Web Apps By Matt Gillespie D olby Digital Plus is an integral part of the Microsoft Edge browser that accompanies Microsoft Windows 10, redefining the sound experience for users of online media and applications. For the first time, professional-quality audio is deliverable in a streaming context, within the bandwidth constraints of mainstream end users. This advance includes both crystal-clear sound resolution, even in challenging environments, as well as multidimensional surround sound, even with modest playback resources. Historically, Internet-based experiences have made compromises in sound quality, compared to the baseline expectations for visuals. While high-definition video has become the norm in most circumstances, developers, content providers, and end users have settled for legacy sound that is limited to two-channel stereo, which suffers the effects of bulky, inefficient codecs such as MP3 and AAC. By licensing Dolby Digital Plus within both Windows 10 and the Edge browser, Microsoft enables premium online audio, dramatically improving upon customary expectations. The Dolby Digital Plus experience is reminiscent of the sound presentation in a movie theater, with up to 8 channels and 5.1 or 7.1 surround or virtual surround sound. High-Fidelity Sound is the New Normal for Internet- Based Usage The content-delivery industry continues its rapid shift toward online usage models. Traditional television is widely recognized as being increasingly eclipsed by Internet-based viewing. At the same time, both consumers and businesses of all sizes are adopting cloud- based services at an accelerating pace. Conventional assumptions for how software is consumed are also shifting, led by wholesale moves toward the cloud such as Office 365 and Adobe Creative Cloud. Real-time online meetings and collaboration are an increasingly important part of corporate operations. These shifts combine to make the browser more important than ever before for consuming software and media content. At the same time, audio under these new models continues to be plagued by poor latency and fidelity. For entertainment purposes, Internetbased streaming audio is generally underwhelming, and in business usages, it can make users strain to hear what is being said in audio conferencing and similar applications. The algorithms in Dolby Digital Plus deliver superior realism, for immersive sound clarity, texture, and dimension. 6 Back to Contents
The industry has finally seen a resolution to the chief compromise in delivering online content between making data sizes small enough for efficient delivery, versus retaining enough quality to provide a good experience for end users. Historically, technical limitations have pushed that balance toward loss of fidelity in the interest of efficient use of bandwidth. Limited or even mediocre sound reproduction has become the norm, with audio held to a lower standard than the video that accompanies it. With the advent of Dolby Digital Plus support in the Edge browser, a better alternative has arisen. Teaming Up with a New Browser, for a New Era Now that the Edge browser, which is part of Windows 10, embraces Dolby Digital Plus and the outstanding audio experiences it enables, a new baseline has been established. The Edge browser, which was developed under the codename Project Spartan, is lightweight and built for robust support of standards. It has been developed from the ground up for performance and the extensibility to support existing and future technologies. Using the Dolby Digital Plus Playback capability in Windows Edge, websites can support premium sound on systems based on Windows 10, including surround for enhanced realism. On systems where Dolby Digital Plus is not available, web applications can programmatically call Internet Explorer to support legacy sound technologies. This seamless integration means that web developers are not forced to make a choice. Next-Generation User Experiences from HTML5 and Dolby Audio Using Dolby Digital Plus, immersive audio can be delivered over the wire with an unprecedented combination of high quality and compression. The Dolby Digital Plus codec makes professional quality audio available even to constrained devices and using low bit rates. In addition to enriched experiences in streaming movies and other video, new opportunities exist for software and service providers in streaming music and online gaming environments. In particular, enhanced audio based on Dolby Digital Plus helps providers meet the growing enduser expectations that have been set by industry-leading games and media, as those providers make strategic moves to online delivery models. Web apps can access Dolby Digital Plus directly, just as they would any other codec, as a simple addition to existing workflows. The current versions of popular development tools, including Adobe Premier Pro, Avid Pro Tools, Audacity, Azure Media Services, and Encoding. com provide simple mechanisms to generate Dolby Digital Plus content directly from their main interfaces. Developers of web apps simply need to perform browser feature detection to verify that Dolby Digital Plus is supported on the target system (see this tutorial for more information). Doing so takes just a few simple lines of code, and if necessary, the app can automatically fall back to a legacy audio delivery format, such as MP3. This approach allows for simple support of Dolby Digital Plus, with seamless support for the most appropriate audio format, transparently to the end user. Conclusion Forward-looking web applications can now build in immersive audio that is well prepared for the future. The Microsoft roadmap for the Edge browser provides ongoing intelligence that developers can use to align ongoing advances in their offerings with those of the user environment. Experience the difference for yourself with the Lux Ahoy web-based game at www.luxahoy.com 7 Back to Contents