Audio descriptions
AWS Elemental MediaConvert supports two different workflows for including broadcast audio descriptions in your output.
You can mix an audio description with other audio content if your input contains an audio description audio signal and an audio description data stream. An audio description audio signal is a spoken description of a video, made for people who cannot see the visual content. An audio description data stream contains fade and pan data used by an encoder. MediaConvert uses this data stream to temporarily lower the volume of other audio channels while an audio description is active.
If your input already has pre-mixed audio descriptions instead of an audio signal and data stream channel, you can signal it to downstream systems by writing audio description metadata in your output.
For more information about audio descriptions, see BBC WHP
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