[Libav-user] Crashes when using dxva2

[wm4]

On Wed, 30 Apr 2014 17:55:11 +0200
"Philippe C.D. Robert" <philippe.robert at 3dimpactmedia.com> wrote:

> Hello,
> 
> I am new to the list, so please forgive me if my question was already discussed and/or this is the wrong list...
> 
> We are trying to use the dxva2 decoder with libavcodec to decode h264 videos on the GPU (version 1.2.6, Windows 7, MinGW). Now, after initialising DXVA2 and setting up the AvCodecContext we get strange crashes. This is the reported stack trace:
> 
> 6A1BF24B 076E4020 00000000 075A0080 avcodec-54.dll!avpriv_dv_codec_profile
> 6A23D778 00000000 07FA5340 00017ACD avcodec-54.dll!avpriv_h264_has_num_reorder_frames
> 6A23DECA 0759FC10 005C0000 0759FC00 avcodec-54.dll!avpriv_h264_has_num_reorder_frames
> 6A4417FD 0759FC10 0759FC10 00000000 avcodec-54.dll!av_parser_close
> 6A44111F 0759FC10 00000000 00000000 avcodec-54.dll!av_parser_close
> 7FEFF34415F 7FEFF3D1EA0 0759FC10 00000000 msvcrt.dll!srand
> 7FEFF346EBD 00000000 00000000 00000000 msvcrt.dll!_ftime64_s
> 76FF59ED 00000000 00000000 00000000 kernel32.dll!BaseThreadInitThunk
> 7722C541 00000000 00000000 00000000 ntdll.dll!RtlUserThreadStart
> 
> I don't understand what is going on here, as avpriv_h264_has_num_reorder_frames does not call avpriv_dv_codec_profile AFAIK.  
> 
> Any Ideas what could go wrong? Is there an example available that shows how to use the dxva2 decoder properly?

There's ffmpeg_dxva2.c in the ffmpeg sources. I suppose it was made for
testing dxva2 support, so maybe it's helpful.