[FFmpeg-devel] [PATCH] matroskadec: execute seekheads recursively

[Rodger Combs]

> On Oct 17, 2014, at 17:40, Michael Niedermayer <michaelni at gmx.at> wrote:
> 
> On Fri, Oct 17, 2014 at 03:27:49PM +0200, Michael Niedermayer wrote:
>> On Fri, Oct 17, 2014 at 01:55:35AM -0500, Rodger Combs wrote:
>>> 
>>>> On Oct 17, 2014, at 01:52, Rodger Combs <rodger.combs at gmail.com> wrote:
>>>> 
>>>> 
>>>>> On Oct 17, 2014, at 01:16, Rodger Combs <rodger.combs at gmail.com <mailto:rodger.combs at gmail.com>> wrote:
>>>>> 
>>>>> This fixes https://trac.ffmpeg.org/ticket/3934 <https://trac.ffmpeg.org/ticket/3934>, but I'm not sure if there was a good reason for this to be here to begin with. Perhaps a protection against infinite recursion (though I believe EBML_MAX_DEPTH serves that purpose to some degree)?
>>>>> <0001-matroskadec-execute-seekheads-recursively.patch>
>>>> 
>>>> Evidently either I or my mail client screwed up and the patch didn't get attached. Whoops.
>>>> <0001-matroskadec-execute-seekheads-recursively.patch>
>>>> Let's try that again...
>>> 
>>> Welp, apparently my email client's borked badly in some way. Here's a gist link instead: https://gist.github.com/08f111e72b8b5ddba078
>> 
>> copy and pasted so our archives dont depend on external links as well
>> as for easy revieweing
>> 
>> From 4cf14a9d117da69b64c267e6f982931cfa60a300 Mon Sep 17 00:00:00 2001
>> From: Rodger Combs <rodger.combs at gmail.com>
>> Date: Fri, 17 Oct 2014 00:35:12 -0500
>> Subject: [PATCH] matroskadec: execute seekheads recursively
>> 
>> Fixes https://trac.ffmpeg.org/ticket/3934
>> ---
>> libavformat/matroskadec.c | 1 -
>> 1 file changed, 1 deletion(-)
>> 
>> diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
>> index b742319..b437e74 100644
>> --- a/libavformat/matroskadec.c
>> +++ b/libavformat/matroskadec.c
>> @@ -1368,7 +1368,6 @@ static int matroska_parse_seekhead_entry(MatroskaDemuxContext *matroska,
>>     int ret = 0;
>> 
>>     if (idx >= seekhead_list->nb_elem            ||
>> -        seekhead[idx].id == MATROSKA_ID_SEEKHEAD ||
>>         seekhead[idx].id == MATROSKA_ID_CLUSTER)
>>         return 0;
> 
> ebml_parse() that gets called as a result of this change does not
> succeed and causes the one and only seekhead entry to return failure
> so i think this doesnt execute seekheads recursively
> 
> [...]
> 
> -- 
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> It is dangerous to be right in matters on which the established authorities
> are wrong. -- Voltaire
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org <mailto:ffmpeg-devel at ffmpeg.org>
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel <http://ffmpeg.org/mailman/listinfo/ffmpeg-devel>
Just stepped through this; I also see ebml_parse() failing with the clip I originally uploaded, but not with the original source file, which I've uploaded to Dropbox: https://www.dropbox.com/s/32ve4hp567ukikt/Maken-Ki%21%20-%20S01E02.mkv?dl=0