A stream is a combination of tracks (or one track) required to render a channel, object, HOA component or pack. The audioStreamFormat establishes a relationship between audioTrackFormats and the audioChannelFormats or audioPackFormat. Its main use is to deal with non-PCM encoded tracks, where one or more audioTrackFormats must be combined to represent a decodable signal that covers several audioChannelFormats (by referencing an audioPackFormat). For PCM audio, an audioStreamFormat will refer to a single audioTrackFormat and a single audioChannelFormat.


<audioStreamFormat audioStreamFormatID="AS_00031001"
                   formatLabel="0001" formatDefinition="PCM">


Attribute Description Example Required
audioStreamFormatName Name of the stream PCM_FrontLeft Yes
audioStreamFormatID ID for the stream. The yyyy digits of AS_yyyyxxxx represent the type of audio contained in the stream. The xxxx digits should match the audioChannelFormat xxxx digits. AS_00010001 Yes
formatLabel Descriptor of the format 0001 Optional
formatDefinition Description of the format PCM Optional

* At least one of formatLabel or formatDefinition is required.


Element Description Example Quantity
audioChannelFormatIDRef Reference to audioChannelFormat AC_00010001 0 or 1
audioPackFormatIDRef Reference to audioPackFormat AP_00010003 0 or 1
audioTrackFormatIDRef Reference to audioTrackFormat AT_00010001_01 0…*

Only one of audioPackFormatIDRef or audioChannelFormatIDRef can be used, not both in the same element.