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Dolby Digital Plus and ISO base media file formatThis section describes the process of analyzing and preparing a Dolby Digital Plus bitstream for online delivery within an ISO base media file.
File-type boxAn ISO base media file that contains the Dolby Digital Plus stream must indicate that the file complies with Dolby extensions by using the file-type box (ftyp).

IntroductionThis documentation supports the system designers and engineers who are building a content creation product. It lists the requirements for creating Dolby Digital Plus content in such a product and provides guidance to help in meeting the requirements.
Product overviewA typical product built and tested using the resources in this kit delivers Dolby Digital Plus content in an online container that supports adaptive streaming.
RequirementsAn online delivery content creation product must meet all defined requirements for the online delivery formats it supports.
Dolby Digital Plus streams in online delivery formatsThe Dolby Digital Plus format provides a high level of flexibility and can support complex bitstream configurations. To minimize impact on decoding devices while ensuring that a wide range of applications can be supported, some constraints are applied to the permitted bitstream structure and to bitstream parameter settings.
Dolby Digital Plus and MPEG-DASHThese topics provide guidance to assist you in meeting the requirements for delivering Dolby Digital Plus streams using the MPEG-DASH standard in conjunction with the ISO base media file format.
Dolby Digital Plus and HTTP Live StreamingThis section specifies the required data formatting and signaling between the server (sender) and the clients (receivers) to use Dolby Digital Plus audio bitstreams in Apple HTTP Live Streaming audio/video (A/V) delivery applications.
Dolby Digital Plus and ISO base media file formatThis section describes the process of analyzing and preparing a Dolby Digital Plus bitstream for online delivery within an ISO base media file.
- Contents of the MP4 sampleBuilding an MP4 sample from a Dolby Digital Plus bitstream must meet certain conditions.
- Parsing a Dolby Digital Plus bitstreamA product must use several bitstream information fields in the Dolby Digital Plus bitstream to identify access units and to properly signal the Dolby Digital Plus bitstream information in the MP4 file.
- Signaling Dolby Digital Plus bitstreams in an ISO base media fileThe 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.
- Signaling Dolby Digital Plus bitstreams with Dolby Atmos content in an ISO base media format fileIn addition to the definitions in Annex F of ETSI TS 102 366, other information must be added to the EC3SpecificBox in a backward-compatible way to describe the characteristics of the Dolby Atmos content carried by a Dolby Digital Plus stream.
- Signaling Dolby Digital Plus bitstreams in an encrypted ISO base media file When Dolby Digital Plus bitstreams are included in an encrypted ISO base media file, the header type value of the EC3SampleEntry box must be set to enca (a protected sample entry), indicating protection encapsulation as described in section 8.12 of ISO/IEC 14496-12. This prevents a playback client that is unable to decrypt the file from otherwise attempting to decode the Dolby Digital Plus audio data.
- File-type boxAn ISO base media file that contains the Dolby Digital Plus stream must indicate that the file complies with Dolby extensions by using the file-type box (ftyp).
- Deriving the contents of the EC3SpecificBoxThis topic provides additional details on the information specific to Dolby Digital Plus and how information is derived from the Dolby Digital Plus bitstream parameters.
Glossary
Notices

File-type box

An ISO base media file that contains the Dolby Digital Plus stream must indicate that the file complies with Dolby extensions by using the file-type box (ftyp).

In the file type-box (ftyp):

Set the value of the compatible_brands field to dby1.
Set the value of the major_brand field to the ISO-defined brand (for example, mp42).