Grass Valley Imagestore 750 v.3.0.1 - Manual (Page 158)

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Advanced Audio
Audio Description (AD)
An audio configuration with a single audio feed connected to an AD block is shown in the
following ‘Audio Graph’ example:
Fig. 6-26: Imagestore 750 Configurator - Audio graph, Audio Description block
The PGM output gives the following audio on its first four channels:
1 Stereo-left background audio.
2 Stereo-right background audio.
3 Stereo-left background audio with AD commentary mix.
4 Stereo-right background audio with AD commentary mix.
The channels (or pins) of the input audio feed contain the following signals:
1 Stereo-left background audio.
2 Stereo-right background audio.
3 AD commentary track.
4 AD control tone.
The first two input pins are passed-through to the ‘SDI PGM Output’ block (pins 1 and 2) to give
a straight copy of the stereo background audio. All four input pins are then connected to the
relevant pins of the AD block, the output of which is routed to pins 3 and 4 of the ‘SDI PGM
Output’ block.
An audio configuration with dual audio feeds plus an A/B-mixer feeding an AD block is shown in
the following ‘Audio Graph’ sample:
Fig. 6-27: Imagestore 750 Configurator - Audio Description audio graph