[Matroska-devel] S_DVBSUB

Steve Lhomme slhomme at matroska.org
Sat Feb 26 13:04:42 CET 2011

On Sat, Feb 26, 2011 at 12:48 PM, Andreas Öman <andreas at lonelycoder.com> wrote:
>> OK so the only stipulation I would have is that if the muxer is not going
>> to store composition and ancillary IDs in CodecPrivate then they MUST reset
>> the page ID on all segments to a single known value. (0 would be OK) That
>> way programs that need those values can default to known value if the
>> CodecPrivate data does not exist.
>> Also are we agreed that the CodecPrivate will contain data in the same
>> format as the descriptor data from the TS PMT? It has the following
>> format...
>> ISO_639_language_code - 24 bits
>> subtitling_type                - 8 bits
>> composition_page_id      - 16 bits
>> ancillary_page_id           - 16 bits
> Makes sense but I guess it would be preferred if applications also sets the
> normal track language tag?
> Also, which one should take precedence if they differ during demuxing? I
> would expect that the native matroska tag is preferred in those cases?

Yes, all information that is inside a codec and also exists at the
container should also appear in the container. And the container takes
precedence. Just like video width/height and forcing an aspect ratio.

>> Normally this is stored as an array for each substream, but since we're
>> only allowing a single stream to be stored in each MKV track we could
>> stipulate that the CodecPrivate can only contain these 8 bytes.
>> Dan

Steve Lhomme
Matroska association Chairman

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