

SHOULD employ meaningful values for Codec ID and Codec Name that they have reason SHOULD assume that all Codec Mappings they create might become standardized, public,Ĭommonly deployed, or usable across multiple implementations. Recommendations for the Creation of New Codec MappingsĬreators of new Codec Mappings to be used in the context of Matroska: The Codec ID of another Codec Mapping that has superseded the Codec Mapping. If used, the Superseded By value MUST store Superseded ByĪ Codec Mapping MAY only be defined with a Superseded By value, if it has anĮxpressed Deprecation Date. Then it is RECOMMENDED that Matroska writers SHOULD NOT use the Codec Mapping after the Deprecation Date. If a Codec Mapping is defined with a Deprecation Date, Deprecation DateĪ timestamp, expressed in that notes when support for the Codec Mapping ĭocumentation of the associated normative and informative references for the codec is RECOMMENDED. The following XML depicts the nested Elements of a BlockGroup Element with an example of BlockAdditions: See (#block-additional-mapping) on Block Additional Mappings for more information. The values of BlockAddID that are 2 of greater have no semantic meaning, but simplyĪssociate the BlockMore Element with a BlockAdditionMapping of the associated Track. Indicates that the context of the BlockAdditional data is defined by the corresponding Codec Mapping.īlockAddID values of 2 and greater are mapped to the BlockAddIDValue of the BlockAdditionMapping of the associated Track. The following table defines the meanings of BlockAddID values. This BlockAdditional data MAYīe passed to the associated decoder along with the content of the Block Element.Įach BlockAdditional is coupled with a BlockAddID that identifies the kind of data The BlockAdditional Element of a BlockMore Element. Codec BlockAdditionsĪdditional data that contextualizes or supplements a Block can be stored within Stored in the CodecPrivate Element is known as Private Data. Data that is defined Initialization to be Then none MUST be used to define the Initialization and the CodecPrivate Element SHOULD NOT be written and MUST be ignored. If the encoding does not require any form of Initialization, Within a track, then that updated Initialization data MUST be written into the CodecState Element Which MUST be stored within the CodecPrivate Element. The Initialization MUST describe the storage of data necessary to initialize the decoder,

InitializationĮach encoding supported for storage in Matroska MUST have a defined Initialization. This value is only intended for human consumption. DescriptionĪn optional description for the encoding. The Codec Name provides a readable label for the encoding. The following table provides examples of valid Codec IDs and their components: Codec ID PrefixĮach encoding supported for storage in Matroska MUST have a Codec Name. Underscore (“_”), and forward slash (“/”). The Codec ID Suffix MUST be composed of only capital letters (A-Z), numbers (0-9), The Major Codec ID MUST be composed of only capital letters (A-Z) and numbers (0-9). If a Codec ID Suffix is used, then the Codec ID MUST include aįorward slash (“/”) as a separator between the Major Codec ID and the Codec ID Suffix. All characters of a Codec ID Prefix MUST beĬapital letters (A-Z) except for the last character of a Codec ID Prefix which MUST beĮach Codec ID MUST include a Major Codec ID immediately following the Codec ID Prefix.Ī Major Codec ID MAY be followed by an OPTIONAL Codec ID Suffix to communicate a refinement Codec IDĮach codec supported for storage in Matroska MUST have a unique Codec ID.Įach Codec ID MUST be prefixed with the string from the following table according to Support for a codec is defined in Matroska with the following values. Us on our development mailing list (cellar at ). If you feel we missed support for a very important codec, please tell Need a well defined Codec ID so that all developers supporting Matroska will use the The intention behind this list is not to list all existing audio and video codecs,īut rather to list those codecs that are currently supported in Matroska and therefore In order to provide its decoder with context and technical metadata. Certain encodings MAY also require some form of codec initialization This Codec ID is a unique registered identifier that represents the encoding stored within A Codec Mapping is a set of attributes to identify, name, and contextualize the formatĪnd characteristics of encoded data that can be contained within Matroska Clusters.Įach TrackEntry used within Matroska MUST reference a defined Codec Mapping using theĬodec ID to identify and describe the format of the encoded data in its associated Clusters.
