1 Visoka škola elektrotehnike i računarstva Sound and video technology (film, home theater, television) Beograd, jun 2014 Dragan Drincic
2 The origins and development of multichannel sound on film First commercially acceptable multichanel formats of sound reproduction developed in the early 1950s on the film (The rapid development of the film industry because of competition from television) Based on these experiences the seventies and eighties advancing the analog surround film formats (Dolby Stereo, Dolby SR) In the early nineties - Digital Surround formats (CDs, Dolby Digital, DTS, SDDS)
3 Analog sound formats on film
4 The first multi-channel audio formats on film Single-chanel tone: Optical recordning Pseudo - binaural tone (tone perspective): Optical recordning Cinema Scope - (35 mm) 4 channel magnetic recording Todd-AO - (70 mm): 6 channel magnetic recording
5 Single-channel optical tone on film Sound track is located along the edge of the film tape
6 Perspecta - optical tone Optical one-channel tone applied to the three speakers by intensity that defines the three control signals (30 Hz, 35 Hz and 40 Hz), depending on the position of the sound source in the picture Control signals are overrecorded on the basic audio signal (60 Hz - 8 khz)
7 Multichannel magnetic records on the film tape Sinema Scope (35 mm): 4 chanels Todd-AO (70 mm): 6 chanels
8 Playing 6 channels in Todd-AO system
9 Shutting down the magnetic field in the film Despite the significantly improved quality of cinema tone, using the magnetic tracks, the application of this system in practice, after the initial "boom" began to decline. The main reasons: Higher price of tapes with magnetic tracks The shorter life of the tape with magnetic tracks High cost of maintenance and playback equipment
10 Analog optical multichannel cinema audio formats 1975 Dolby stereo (Dolby analog) Dolby SR (Spectral Recording)
11 1975 Dolby stereo (Dolby analog) Standard film tape - 35 mm - the same width as the previous mono optical channel, saved with a two tone optical recording Two optical-tracks hold 4 channels (left and right channel, matrix encoded C channel and surround (ambient channel and effects) Playback: 2:4 decoder Coding and decoding process : 4:2:4
12 Dolby stereo The decoding method and speaker placement
13 Dolby SR (Spectral Recording) Enhanced version - eliminating noise (based on previous formats: Dolby A, B and C) Used as optical analog format on almost all 35mm film tape - Dolby SR analog
14 Digital multi-channel cinema audio formats
15 1990 first 5.1 chanal digital format: Cinema Digital Sound (CDS) Optical Radiation Corporation + Kodak
16 three competing digital audio formats on 35 mm tape Dolby Digital Digital Theatre Sound (DTS) Sony Dynamics Digital Sound (SDDS)
17 The Universal film tape - 35 mm
18 Dolby Digital - cinema The center speaker - usually placed above the screen - used to reproduce dialogue Two front channels: left - right Two channels for rear speakers - noise and the ambient sound Channel for low frequency - reproduction of special effects (such as explosions, earthquakes)
19 Dolby digital cinema (SR-D) - 5.1
20 Dolby Digital Surround EX Dolby Digital EX - extra surround channel - matrix encoded into the existing surround (left and right) channels of standard digital audio Provided the compatibility with standard 5.1 system for playback. Users who want additional surround channel must have added the decoder unit and power amplifier. Existing surround speakers can be utilized.
21 Dolby Digital Surround Ex
22 DTS (Digital Theater Sound) On film tape is loaded a time code for images sincronization with the sound. Sound is on a separate compact disk. Uses 4 times less compression than Dolby Digital signal Digitization of 20 bits instead of 16 (in Dolby Digital) Basic version 6 DTS playback in standard 5.1 format.
23 DTS (versions) DTS ES (Digital Theater Sound Extended Surround) 6.1 standard (additional rear surround channel) DTS ES Matrix - seventh channel encoded in the primary channel. DTS ES Discrete - all the channels are independent. DTS 94/ format (24 bit, 96 khz) and high-quality video on DVD - Video disc
24 SDDS "Sony Dynamic Digital Sound" format 5 channels behind the screen (left, left center, center, right center, right) 2 surround channels (left surround, right surround) 1 Subwoofer Channel Since the additional hardware for playback of 8 channels is neded, significantly more expensive is installation of this system. It was designed for a larger acoustic spaces.
25 SDDS "Sony Dynamic Digital Sound" format This system can play sound in two versions: 8 channels or 6 channels. Most installations using 6 channels (3 behind the screen). 8 channels are used only in cases where the screen is big enough (five chanels behind the screen). Losing the race with Dolby Digital and DTS formats
26 TV and two-channel stereo sound
27 Optimum position for TV watching A typical listener watching the TV screen at an angle of 16 The optimum angle for stereo speakers is 60 A good compromise for the angle between the speaker for stereo TV is 30 The distance of the speakers from TV screen is aproximatelly 30 cm (to avoid magnetic interference)
28 TV and two-channel stereo sound
29 Analog home multichannel formats
30 Dolby Surround Dolby Surround is a commercial version of the original multi-channel movie sound formats Dolby analog and Dolby SR In this format, four-channel audio material (left, center, right and mono surround) are matrix encoded on two audio tracks. These tracs are then distributed to the stereo soundcarriers (video tape or stereo TV program). In home reproduction they decoded using Dolby ProLogic decoder and again get four audio channels.
31 Dolby Pro Logic II Reconstructed (decoded) surround sound from stereo sources
33 Dolby Pro Logic II Home Theater
34 Pro Logic IIx Pro Logic IIx - format with 6.1-or 7.1-channels Three modes of listening: film, music, games For example. In mode "games", special effekts signals are reproduced from the surround channels (for a fuller expression)
35 Dolby Pro Logic IIz There are two additional front channels elevated above the screen to create some special effects - rain, wind,... Listeners are more sensitive to sound stimuli coming from the front than from the back, which is the reason why the additional speakers pozitioned above the screen
36 Dolby Pro Logic IIz ( )
37 Dolby Pro Logic IIz ( )
38 Digital multi channel sound home formats
39 With the advent of multi-channel digital audio recording on the film Dolby Digital replaces Dolby Surround for home use (DVD-video, digital TV, games). Each Dolby Digital decoder, among other outputs has a stereo signal compatible with Dolby Pro Logic decoder.
40 Dolby Digital In addition to the basic version intended for home use Dolby Digital is used as the base for: Radio and TV broadcasting Transmission by satellite Transmission over digital cable systems Almost every modern DVD-Video player have: Two-channel output from the recorded Dolby Digital 5.1 format, and digital output for connection to a 5.1 audio / video receiver.
42 Dolby Digital (5.1 sistem za kuću)
43 Dolby Digital home theater
45 Dolby Digital Plus Up to 7.1 channels Compatible with modern A / V receivers The maximum data rate to 6 Mbps. At least 3 Mbps on HD DVD up to 1.7 Mbps on Blu - ray discs.
46 Dolby TrueHD Up to 7.1 channels of surround sound, with the possibility of expansion in the future The encoding - decoding without any loss of quality (reproduction of the finest details of the original material) Data speed up to 18 Mbps 8 channels of full-scale (24-bit/96 khz) 5.1 channels (24-bit/192 khz)
47 Dolby illuzion
48 Dolby headphones Generate acoustic "illusion" - you have the impression that by the classical stereo headphones listening 5.1 home theater system This is possible because the sound of a given source reaches each ear, with slightly different characteristics. Our brains are needed these small differences to extract everything we want to know about that sound. Formed five virtual channels. Low frequency signal (subwoofer signal) is saved in the left and right channels with identical level.
49 Dolby Virtual Speakers Simulation of 5.1 surround sound when playing with only two speakers. Application in: digital TV, stereo mini systems, personal computers (PC), and a number of audio / video consumer devices No additional speakers, stands, cables are neded
50 Spatial or 3D sound reproduction
52 Home Theater
53 Home Theater practical prezentation
55 NHK Science and Technical Research Laboratories - Tokyo, Japan
57 Live recording, transmission and reproduction of the system of Olympic game in London
58 Dolby products related with Height
60 Positions of speakers
61 Positions of speakers from the front
62 Positions of speakers on the side wall