[FFmpeg-devel] [PATCH] Fix ogg demuxer with broken (continuation) files [issue 798]

[Alex Converse]

On Mon, Feb 9, 2009 at 4:36 AM, M?ns Rullg?rd <mans at mansr.com> wrote:
>
> Alex Converse <alex.converse at gmail.com> writes:
>
> > On Mon, Jan 26, 2009 at 4:22 AM, M?ns Rullg?rd <mans at mansr.com> wrote:
> >> Peter Ross <pross at xvid.org> writes:
> >>
> >>> Hi,
> >>>
> >>> This patch makes the ogg demuxer function with malformed ogg files where the continuation
> >>> flag is set incorrectly.
> >>>
> >>> Example. http://ftp.heanet.ie/mirrors/fosdem-video/2008/maintracks/FOSDEM2008-swpat.ogg
> >>> contains stupid page/segment configurations like this:
> >>>
> >>>  PAGE N
> >>>     SEGMENT (236 bytes)
> >>>     SEGMENT (255 bytes)
> >>>  PAGE N+1, continuation flag not set
> >>>     SEGMENT (0 bytes)
> >>>     SEGMENT (253 bytes)
> >>>     ...
> >>
> >> For some reason those file work perfectly with the original demuxer.
> >> I'd like to find out why before patching anything.
> >>
> >
> > What do you mean by "the original demuxer?" libogg?
>
> Sorry, that was unclear.  I meant my original demuxer that was ported
> to lavf.  I also forgot about this issue.  I easily forget about Ogg.
> That's the only way I can remain sane.
>

it looks like theora in ogg support was added to ffmpeg in r4217 at
which point the FOSDEM file is broken in the exact same way. While I
appreciate the idea that on paper it should work, if you are unwilling
to do the legwork on tracking down where this then I think we should
move forwards with Peter Ross's patch.

--Alex