[FFmpeg-trac] #3093(documentation:reopened): exception at 0x52B832F8 (avutil-52.dll) in filtering_video.exe: 0xC0000005: Access violation reading location 0xFEEEFEF2.

FFmpeg trac at avcodec.org
Mon Nov 11 02:42:33 CET 2013


#3093: exception at 0x52B832F8 (avutil-52.dll) in filtering_video.exe: 0xC0000005:
Access violation reading location 0xFEEEFEF2.
-------------------------------------+-------------------------------------
             Reporter:  ahsan        |                    Owner:
                 Type:  defect       |                   Status:  reopened
             Priority:  important    |                Component:
              Version:  git-master   |  documentation
             Keywords:  examples     |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by ahsan):

 Hi Ubitux,

 I am trying to merge, demux and mux example codes so that i can take in
 any .mp4/.avi/mpg files and then re-encode them in the same format

 I am having following issues

 1. MUX example code uses avformat_alloc_output_context2() to create the
 output context
    for example for .mpg it will choose MPEG1 encoder, the .mpg file i used
 is encoded
    using MPEG2 encoder. I was wondering how can i select different
 encoders, is there
    any API call which i can use to re-set the encoder name in the context
 encoder fails

 2. I uses the fmt_ctx from decoder to set the encoder parameters, i try to
 memcpy the
    context (decoder to encoder for the codec) but it fails
    by setting the different parameters from fmt_ctx to the c
    c->width    = fmt_ctx->streams[video_stream_idx]->codec->width;
    c->height   = fmt_ctx->streams[video_stream_idx]->codec->height;
    c->coded_width    =
 fmt_ctx->streams[video_stream_idx]->codec->coded_width;
    ........................
    c->gop_size    = fmt_ctx->streams[video_stream_idx]->codec->gop_size;
                    /* emit one intra frame every twelve frames at most */
    c->bit_rate = (fmt_ctx->streams[video_stream_idx]->codec->bit_rate ==
 0) ? 400000 :
                   fmt_ctx->streams[video_stream_idx]->codec->bit_rate;
                   /* i am seting it to 400kbps in case it is set to 0 as i
 am seeing it
                      for some stream */
   ........................

   I am seeing different issue
   1. GOP Size fmt_ctx most of the time has gop_size = 12 which does not
 seems like the case
   for the stream

   2. bit-rate i am getting in the output .mp4 is way higher then the one i
 see from the
      fmt_ctx, it seems like encoded bit-stream is in 50Mbits/sec where as
 input .mp4 was
      300kbps or 400kbps bit-rate

   I am wondering what is the best way to set the encoder context using the
 input bitstream
   [.mp4, .avi, .mpg etc] files

 Regards
 Ahsan

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/3093#comment:12>
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