[FFmpeg-devel] [PATCH 0/1] avformat/mpegts: fix first NAL start code splited in two different packets

Kieran Kunhya kierank at obe.tv
Tue Feb 6 13:28:38 EET 2024


On Tue, 6 Feb 2024 at 10:58, Nicolas Gaullier <nicolas.gaullier at cji.paris>
wrote:

> >Envoyé : vendredi 2 février 2024 16:24
> >À : ffmpeg-devel at ffmpeg.org
> >Objet : [PATCH 0/1] avformat/mpegts: fix first NAL start code splited in
> two different packets
> >
> >This issue happens in the following case:
> >- unaligned PES and NAL encoding
> >- the first NAL of the access unit begins at the very end of a ts packet,
> sometimes only the 0x00 of the trailing byte (unfortunately, this is still
> conformant to the standards!)
> >- the video frame is so small (ex: typically still picture) it fits in a
> ts packet and a new PES is immediately started
> >
> >Two sample files can be found here:
> >a) https://0x0.st/HDwD.ts
> >b) https://0x0.st/HDwd.ts
> >
> >For sample a, the first NAL (AUD) is splited this way:
> >0x00 / 0x00 0x00 0x01 0x09
> >And for sample b:
> >0x00 0x00 0x00 / 0x01 0x09
> >
> >ffmpeg -i input.ts -f null /dev/null
> >=> Application provided invalid, non monotonically increasing dts...
> >
> >
> >Nicolas Gaullier (1):
> >  avformat/mpegts: fix first NAL start code splited in two different
> >    packets
> >
> > libavformat/mpegts.c | 41 +++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 39 insertions(+), 2 deletions(-)
>
> Ping ?
> If you think it would be better to have a related trac ticket, just tell
> me, I can do this of course.
> Nicolas
>

I think it's ok. I wish it were less ugly but I guess it can't be.

Kieran


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