[MPlayer-dev-eng] Fix when seeking in mpegts using -demuxer lavf

[Reimar Döffinger]

On Thu, Aug 04, 2011 at 09:36:16PM +0200, Etienne Buira wrote:
> Ran into this when playing a mpegts file with -demuxer lavf, r33952 with
> ffmpeg 1816addc.
> 
> A:47387.359 V:47387.615 A-V: -0.255 ct: -0.184   0/  0  6%  0%  0.5% 1 0 
> Program received signal SIGSEGV, Segmentation fault.
> mp_msp_av_log_callback (ptr=0x16b8ab0, level=24, fmt=0xca1d29 "Continuity Check Failed\n", vl=0x7fffffffb590) at libmpcodecs/vd_ffmpeg.c:201

A backtrace would be useful since this might be a bad av_log call in
FFmpeg.

> Attached patch fixes that.

> Index: libmpcodecs/vd_ffmpeg.c
> ===================================================================
> --- libmpcodecs/vd_ffmpeg.c	(revision 33952)
> +++ libmpcodecs/vd_ffmpeg.c	(working copy)
> @@ -197,7 +197,7 @@
>      default          :  mp_level= level > AV_LOG_DEBUG ? MSGL_DBG2 : MSGL_ERR; break;
>      }
>  
> -    if(ptr){
> +    if(ptr && avc){

What's the point of checking ptr?
Even taking future changes into account I can't see how it should
be possible to have a AVClass without having a ptr.