[FFmpeg-devel] [PATCH] assdec: non monotone timestamps

Ivan Kalvachev ikalvachev
Sat Sep 27 20:41:04 CEST 2008

On 9/27/08, Aurelien Jacobs <aurel at gnuage.org> wrote:
> Hi,
> When trying to stream copy the attached ASS file with the following command:
>   ffmpeg -i test.ass -scodec copy test2.ass
> I get some "error, non monotone timestamps". They are due to the fact that
> this file contains several events with the same pts (this is perfectly
> valid ASS). I guess that those events with equal pts should be packed in
> the same AVPacket (the same way all the macroblocks from a video frame are
> stored in a single packet).
> Attached patch just implement this.
> Note that the matroska demuxer has the same problem, and I intend to fix
> it soon.

Just to be clear,
You intent to make mkv demuxer concatenate multiple different packets
stored in the mkv.ass format into one huge packet combining multiple
file.ass lines. All lines in the packet would have same pts, but the
lines may contain different duration than the one of the packet.

Would you also do the mkv muxer side changes - breaking multiple lines
into multiple packets, or the mkv.ass specs already allow this?

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