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• Encoding h.264 with libavcodec/x264

  21 décembre 2010, par Leviathan

  I am attempting to encode video using libavcodec/libavformat. I'm trying to change the standard output-example.c from ffmpeg source. The AVI file is created on the disk, but the only sound is encoded. I tried adding a lot of options for x264 from here. All the other codecs works fine, mpeg2, mpeg4, mjpeg, xvid.
  In addition to specifying the parameters x264, I also set the codec to AVOutputFormat structure. That's all I've done.

    AVOutputFormat  *pOutFormat;  // in header file
  
    av_register_all();
  
    AVCodec *codec = avcodec_find_encoder_by_name("libx264");
  
    pOutFormat = guess_format("avi", NULL, NULL);
  
    pOutFormat->video_codec = codec->id;

  The debug output of my application :

  Output #0, mp4, to 'D:\1.avi':
  
      Stream #0.0: Video: libx264, yuv420p, 320x240, q=10-51, 500 kb/s, 90k tbn, 25 tbc
  
      Stream #0.1: Audio: aac, 44100 Hz, 1 channels, s16, 128 kb/s
  
  [libx264 @ 0x694010]using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2
  
  [libx264 @ 0x694010]bitrate tolerance too small, using .01
  
  [libx264 @ 0x694010]profile Main, level 2.0
  
  [libx264 @ 0x694010]frame I:150   Avg QP:14.76  size:  2534
  
  [libx264 @ 0x694010]mb I  I16..4: 75.9%  0.0% 24.1%
  
  [libx264 @ 0x694010]final ratefactor: 17.57
  
  [libx264 @ 0x694010]coded y,uvDC,uvAC intra: 42.7% 92.4% 47.4%
  
  [libx264 @ 0x694010]i16 v,h,dc,p: 11% 14%  2% 73%
  
  [libx264 @ 0x694010]i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 21% 18% 29%  5%  8% 10%  3%  3%  2%
  
  [libx264 @ 0x694010]kb/s:506.79

• Merge video and audio with ffmpeg. Loop the video while audio is not over

  3 novembre 2016, par fstephany

  I’m trying to merge an audio file with a video file.
  I have two options :

  • Have a very small video file (e.g., 10 seconds) that loop while the audio file is not over.

  • Have a very long video file (longer than any of my audio file) on which I can attach the audio file. I would like to cut the video when the audio is finished.

  I’ve using the latter with the -t option of ffmpeg. It means I have to get the duration of the audio file to feed it into ffmpeg. Is it possible to avoid this step ?

  Any pointer for the first solution ?

• Simple way to grab thumbnail of FLV in ASP.NET without changing permissions on server ?

  23 septembre 2011, par Rhys Causey

  I'm looking for a simple way to grab thumbnails of FLVs in ASP.NET, without having to change any permissions/settings on the server. Ideally, nothing is installed on the server machine, but if necessary, small tools such as FFmpeg are fine.

  I've tried FFmpeg using the command-line tool with Process.Start, but the same command that works in a Windows Forms application and from the command prompt does not work in ASP.NET (presumably because of permissions).

  I've also tried using TAO.FFmpeg, and it seems to be working most of the time, but fails randomly, and does not start working again until the machine is restarted. Even when I use the sample code (decoder.cs), it sometimes fails when I try to open multiple videos in a single request.

  If this isn't possible in a clean/straightforward way, I'm open to other suggestions.