SupplementalProperty descriptor

If the referenced Dolby Digital Plus bitstream carries Dolby Atmos content, the representation includes two additional SupplementalProperty descriptors.

To signal the presence of audio objects, one descriptor uses the SupplementalProperty scheme described in the schemeIdUri: tag:dolby.com,2018:dash:EC3_ExtensionType:2018, and the value element is JOC.

To describe the decoding complexity of the Dolby Digital Plus bitstream with Dolby Atmos content, the other descriptor uses the SupplementalProperty scheme described in the schemeIdUri: tag:dolby.com,2018:dash:EC3_ExtensionComplexityIndex:2018. The value element contains a decimal representation of the eight-bit bit field for complexity_index_type_a in the EC3SpecificBox of a Dolby Digital Plus audio track. The complexity_index_type_a parameter has a value range of 1 to 16.

A playback client can use the information to select the suitable representation according to its decoding capability.