Signaling Dolby Digital Plus bitstreams in an ISO base media file

The basic structures defined within ISO/IEC 14496-12 to identify audio tracks are used with specific extensions (defined in Annex F of ETSI TS 102 366) to provide detailed information on the characteristics of a Dolby Digital Plus stream.

The information is included in the stbl box of the moov box of the ISO base media file. The locations and hierarchy of the boxes that must be included in stbl to identify a Dolby Digital Plus stream within an ISO base media file are listed in the table.

Table 1. Sample table box hierarchy for Dolby Digital Plus audio tracks
Nesting Level
4 5 6 7 Reference
stbl ISO/IEC 14496-12
stsd

EC3SampleEntry

(header type set to ec-3)

Annex F of ETSI TS 102 366

EC3SpecificBox

(header type set to dec3)

Annex F of ETSI TS 102 366 and Deriving the contents of the EC3Specific box section of this information set
stts ISO/IEC 14496-12
stsc
stsz
stz2
stco
co64

In the table, the value of the nesting level provided for each box is based on the structure of the complete ISO base media file, beginning with a nesting value of 0 for the ftyp and moov boxes. The table also includes a reference to where each box is defined.

For an unencrypted ISO base media file, the EC3SampleEntry box header type value is ec-3. The value of the EC3SpecificBox header type is dec3.