On 27/03/13 15:41, Michael Niedermayer wrote:
reserved_count[frame_code] (v) - MUST be <256. + Muxers conforming to this version of the specification MUST set it to + !!(flags[frame_code] & FLAG_SIDEDATA) + Demuxers MUST support any value from 0 to 255 + These rules are to ensure extensibility of the format.
Would enjoy a better explanation. Such as "muxer supporting FLAG_SIDEDATA MUST set the reserved_count to 1 if side data is in used in order to be compatible with older demuxers"
+ +sidedata_size[frame_code] (v) + Size in bytes at the end inside data which represent frame sidedata and + frame metadata.
metadata and sidedata are different items, I'm not exactly cool in lumping everything in the same serialized dictionary.
+ +side_data + This data structure is used both in frames for per frame side and metadata + as well as info tags for metadata covering the whole file, a stream + chapter or other. + Metadata is data that is about the actual data and generally not essential + for correct presentation + Sidedata is semantically part of the data and essential for its correct + presentation. The same syntax is used by both for simplicity. + The use of sidedata should be avoided and the information be put inside + the codec bitstream, if its syntax supports carrying such information.
This statement should be omitted.
+ Types of per frame side data: + "Channels", "ChannelLayout", "SampleRate", "Width", "Height" + This frame changes the number of channels, the channel layout, ... to + the given value (v) + If used in any frame of a stream then every keyframe of the stream + SHOULD carry such sidedata to allow seeking. + "Extradata", "Palette" + This frame changes the codec_specific_data or palette to the given + value (vb) + If used in any frame of a stream then every keyframe of the stream + SHOULD carry such sidedata to allow seeking. + "CodecSpecificSide<num>" + Codec specific side data, equivalent to matroskas BlockAdditional (vb) + the "<num>" should be replaced by a number identifying the type of + side data, it is equivalent/equal to BlockAddId in matroska. + "SkipStart", "SkipEnd" + The decoder should skip/drop the specified number of samples at the + start/end of this frame (v) + "UserData<identifer here>" + User specific side data, the "<identifer here>" should be replaced + by a globally unique identifer of the project that + uses/creates/understands the side data. For example "UserDataFFmpeg"
I'm not certain serializing type and enumeration this way would work that well. lu