MPEG DASH Characterization of Audio Channel Configurations

Last night I assigned myself an action item to explain how MPEG DASH characterizes audio channel configurations.
MPEG DASH (ISO/IEC 23009-1:2022 | IEC<https://webstore.iec.ch/en/publication/78182>) uses a flexible system to describe how audio channels are configured in a media presentation. This system is based on schemeIdURI/value pairs:

  *
Each audio channel configuration is identified by a scheme identifier URI — a unique string that points to a specific way of describing channel layouts.
  *   Along with the scheme identifier, a value is provided that carries the actual channel configuration information according to that scheme.

This approach allows content providers and streaming services to choose whatever scheme best fits their needs and the audio formats they use. There is no one-size-fits-all rule; instead, DASH supports multiple schemes so that different audio technologies and use cases can be accommodated.
That said, to promote interoperability and consistency, MPEG DASH defines a default scheme for audio channel configuration. The default scheme is identified by the URI:
urn:mpeg:mpegB:cicp:ChannelConfiguration
This scheme is defined in the international standard ISO/IEC 23091-3, part of the Coding-Independent Code Points (CICP) series. It provides a standardized way to describe audio channel layouts independent of the codec or container format.
This scheme characterizes audio channel configurations by assigning numeric values that correspond to specific standard channel layouts. These values are defined in ISO/IEC 23091-3 and represent common speaker setups such as:

  *   Mono (1 channel)
  *   Stereo (2 channels: left and right)
  *   5.1 surround sound (6 channels: front left/right, center, LFE, surround left/right)
  *   7.1 surround sound (8 channels)
  *   And other configurations including advanced or immersive audio setups

Each numeric value uniquely identifies a particular channel layout, allowing the DASH client to understand how many audio channels are present and how they are arranged spatially.
For example:
Value
Description
1
Mono
2
Stereo (Left, Right)
3
2.1 (Stereo + LFE)
6
5.1 Surround
8
7.1 Surround
....
Other standardized layouts
Note: Although the example suggests it, the value is not generally equal to the number of channels, specifically for immersive channel layouts.
Best regards,
Wolfgang