EVS XT3 Version 11.00 Configuration Manual - Manual (Page 133)

Dolby Audio Management
Concepts
• Dolby Digital or Dolby 5.1 or AC-3, is an audio coding system containing up to 6
discrete channels of sound, with 5 channels for normal-range speakers (20 Hz -
20,000 Hz) (Right front, Center, Left Front, Right Rear and Left Rear) and one channel
(20 Hz - 120 Hz) for the LFE, or subwoofer.
• Dolby E is a professional coding system optimized for the distribution of surround and
multichannel audio through two-channel postproduction and broadcasting
infrastructures, or for recording surround audio on two audio tracks of conventional
digital video tapes, video servers, communication links, switchers, and routers.
Available Dolby Configurations
Case 1: The 5.1 audio signal is carried on 6 discrete PCM audio
channels
• It is available on an XT3 server in all configurations.
• The audio can be analog, digital or embedded depending on the configuration.
• In AES audio, if the audio is correctly genlocked to the video, the sample rate
converter can be switched off.
Case 2: The 5.1 audio signal is coded in the two-channel Dolby E
standard
• Dolby E over AES/EBU links
◦
Set the configuration of the pair of channels carrying the Dolby E signal to “DY” in
the Multicam Configuration window, Channels tab. This has two effects :
• It disables the sample rate converter on the input channels.
• It forces all transitions to a hard cut.
If the sample rate converter is activated and the audio configuration is a mix between
PCM audio over AES and Dolby E over AES, the sample rate converter will only be
applied to the PCM over AES signal.
• Dolby E Embedded in the SDI/HD SDI stream
◦
Set the configuration of the pair of channels carrying the Dolby E signal to “EY” in
the Multicam Configuration window, Channels tab. This will force the transition to
a hard cut.
◦ The sample rate converter parameter does not apply to embedded audio.
The Dolby E transitions will be correct as long as:
• the configuration is correct
• the AES stream containing Dolby E is correctly synchronized with the video
Dolby E transitions will not be correct (2 frames of mute at the transitions) if the audio type
is set to E instead of EY or D instead of DY.
Audio effects (scrub, slow motion) are not possible in Dolby E. If they are used anyway,
the audio will be muted.
127 3. Multicam Configuration
EVS Broadcast Equipment S.A. - April 2012 Issue 11.00.C