[Ffmpeg-devel] MPEG2 seeking broken

Steve Lhomme steve.lhomme
Tue Mar 7 11:46:53 CET 2006


On Tue, 2006-03-07 at 11:32 +0100, Steve Lhomme wrote:
> Hi everyone,
> 
> As a follow-up to the email I sent a few days ago, I tried ffplay
> (latest from CVS) on Linux on chems1.vob. The default seeking mode of
> ffplay works. 
> 
> But it's not "precise" enough for me (seeking 10s away is too far for
> what we are using to analyse video frames). So I added the value set by
> our application to seek inside any file. Namely I replaced :
> 
> ret = av_seek_frame(is->ic, -1, is->seek_pos, is->seek_flags);
> =>
> ret = av_seek_frame(is->ic, 0, 152393, AVSEEK_FLAG_BACKWARD);
> 
> and also tried :
> 
> ret = av_seek_frame(is->ic, -1, is->seek_pos, is->seek_flags);
> =>
> ret = av_seek_frame(is->ic, 1, 152393, AVSEEK_FLAG_BACKWARD);
> 
> 
> All these values are legitimate (AFAIK). There are 2 streams (1 video
> and 1 audio) and we seek at around 1.6s from the first frame. The
> BACKWARD flag is to ensure we go to the previous keyframe and not the
> next one (otherwise we might miss a lot of content on files like small
> AVIs).
> 
> Both case crash exactly like the MSVC debug build we use. I attach the
> backtrace of gdb in both cases.

I forgot to add this to the gdb log:
(gdb) print ref_picture
$1 = (uint8_t **) 0x0






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