[Matroska-devel] S_DVBSUB

Steve Lhomme slhomme at matroska.org
Wed Feb 23 18:28:16 CET 2011

On Tue, Feb 22, 2011 at 10:47 PM, Dan Haddix <dan6992 at hotmail.com> wrote:
> No. The decoder uses the page ID to decide whether or not to display the
> subtitle based on the composition and ancillary IDs of the selected stream.
> There is no standard way of telling the decoder to ignore the page ID and
> decode everything. All we can do is trick the decoder into displaying
> everything by resetting the page ID on every segment to 1 during muxing and
> then setting the composition and ancillary IDs for all MKV tracks to 1 in
> the player/demuxer. The only other way to do it would be to store the real
> composition and ancillary IDs somewhere in the MKV track, but you seemed to
> be against that originally.

Well, I don't really see why we have to change a value in the stream
if in the end the decoder should not handle it (since the track was
already selected in Matroska). I seems that DVBSUB is a poorly defined
codec if decoders cannot bypass that step.

But in the end I don't care, as we already have to copy common data
into Matroska, I suppose the header in the DVBSUB source packets will
already be managed, so changing it to any other value shouldn't be a
big issue. Just more for on the muxing side.

Steve Lhomme
Matroska association Chairman

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