Overview: Audio decoding and output

The audio playback path connects coded tracks, decoded samples, transport choices and the device producing sound.

A track can be delivered for decoding elsewhere or decoded into samples before output. The chosen route affects channel handling, conversion and the spatial information that reaches the receiving system. This branch follows those choices through passthrough, PCM and fallback, then connects them to synchronization and audio-description use.

• The audio playback path
  The audio playback path connects the selected source track, server delivery, decoding, output transport, and final sound reproduction.

• Output and transport
  Audio output and transport determine whether a receiver gets a coded stream, decoded samples or another defined delivery arrangement.

• Conversion and fallback
  Audio conversion and fallback adapt a source to the available decoding and listening path.

• Preserving immersive audio metadata
  Preserving immersive audio requires carrying the spatial information needed by a renderer through the supported playback stages.

• Audio/video synchronization
  Audio/video synchronization aligns sound and picture on a common playback timeline while accounting for their different delays.

• Audio-description tracks
  Audio-description tracks add spoken descriptions of important visual information for listeners who cannot see the picture clearly.