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• Revision 0359ad7f9a : Skip inverse transform when eob is zero When all the transform coefficients wer

  23 juillet 2013, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_encodemb.c

  
  
  Skip inverse transform when eob is zero

  When all the transform coefficients were quantized to zero, skip
  the inverse transform operation. For bus_cif at 1000 kbps, the
  runtime goes from 154967ms -> 149842ms, i.e., about 3% speed-up,
  at speed 0.

  Change-Id : Ic0a813fff5e28972d4888ee42d8747846a6c3cc6

• How to enable different components of FFMPEG ?

  3 décembre 2011, par Richard77

  I've found this C# wrapper code around FFMPEG. I'm using ASP.NET MVC3 and C#. When trying to get it work, I'm getting the following error :

          RawOutput   "ffmpeg version N-34906-g4e7b3ef, Copyright (c) 2000-2011
  
          the FFmpeg developers
  
  
  
          built on Nov 16 2011 12:35:07 with gcc 4.6.2
  
  
  
          configuration: --enable-gpl --enable-version3 --disable-w32threads 
  
          --enable-runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r 
  
          --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfreetype 
  
          --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-librtmp 
  
          --enable-libschroedinger --enable-libspeex --enable-libtheora 
  
          --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis 
  
          --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid 
  
          --enable-zlib
  
  
  
          libavutil    51. 25. 0 / 51. 25. 0
  
          libavcodec   53. 34. 0 / 53. 34. 0 
  
          libavformat  53. 20. 0 / 53. 20. 0 
  
          libavdevice  53.  4. 0 / 53.  4. 0  
  
          libavfilter   2. 48. 1 /  2. 48. 1 
  
          libswscale    2.  1. 0 /  2.  1. 0 
  
          libpostproc  51.  2. 0 / 51.  2. 0
  
          [wmv3 @ 002BFA00] Extra data: 8 bits left, value: 0
  
          [asf @ 002B8A80] parser not found for codec wmav2, packets or times may be invalid.
  
          Seems stream 1 codec frame rate differs from container frame rate: 1000.00 (1000/1) -> 30.00 (30/1)
  
          Input #0, asf, from 'C:\\FfMpeg\\Videos\\Original\\Video1.wmv':
  
          Metadata:
  
          WMFSDKVersion   : 11.0.6002.18049   
  
          WMFSDKNeeded    : 0.0.0.0000
  
          IsVBR           : 0
  
          Duration: 00:00:41.80, start: 0.000000, bitrate: 888 kb/s
  
          Stream #0:0(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, 2 channels, s16, 64 kb/s
  
          Stream #0:1(eng): Video: wmv3 (Main) (WMV3 / 0x33564D57), yuv420p, 320x240, 786 kb/s, 30 tbr, 1k tbn, 1k tbc
  
          Incompatible pixel format 'yuv420p' for codec 'mjpeg', auto-selecting format 'yuvj420p'
  
          [buffer @ 031D8DA0] w:320 h:240 pixfmt:yuv420p tb:1/1000000 sar:0/1 sws_param:
  
          [buffersink @ 031D8FA0] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
  
          [scale @ 03106C20] w:320 h:240 fmt:yuv420p -> w:320 h:240 fmt:yuvj420p flags:0x4
  
          [wmv3 @ 002BFA00] Extra data: 8 bits left, value: 0
  
          Output #0, image2, to '87334ed0-2bcf-4be5-82ae-9089c14e0323.jpg':
  
          Metadata:
  
          WMFSDKVersion   : 11.0.6002.18049
  
          WMFSDKNeeded    : 0.0.0.0000
  
          IsVBR           : 0
  
          encoder         : Lavf53.20.0
  
          Stream #0:0(eng): Video: mjpeg, yuvj420p, 320x240, q=2-31, 200 kb/s, 90k tbn, 30 tbc
  
          Stream mapping:
  
          Stream #0:1 -> #0:0 (wmv3 -> mjpeg)
  
          Press [q] to stop, [?] for help
  
          [image2 @ 03107920] Could not open file : 87334ed0-2bcf-4be5-82ae-9089c14e0323.jpg
  
          av_interleaved_write_frame(): Input/output error
  
          "   string

  I'm absolutely new to FFMPEG, so I don't know where to start to solve the above probleme.

  EDIT

  public ActionResult Convert()
  
      {
  
          Converter _converter = new Converter(@"C:\FfMpeg\ffmpeg.exe");
  
          OutputPackage oo = _converter.ConvertToFLV(@"C:\FfMpeg\Videos\Original\Video1.wmv");
  
  
  
          FileStream outStream = System.IO.File.OpenWrite(@"C:\FfMpeg\Videos\Converted\Video1.flv");
  
          oo.VideoStream.WriteTo(outStream);
  
          outStream.Flush();
  
          outStream.Close();
  
  
  
          oo.PreviewImage.Save(@"C:\FfMpeg\Videos\Thumbnail\Thumbnail1.jpg");
  
  
  
          return RedirectToAction("WatchMovie");
  
      }

  Thanks for helping

• H264 encoder settings

  30 novembre 2011, par Chris Robinson

  I'm using xuggler to encode a series of images to an MP4 file. I use the following code to setup the IStreamCoder and specify the H264 codec :

  // only set if codec is H264
  
  Configuration.configure("/usr/local/xuggler/share/ffmpeg/libx264-hq.ffpreset",
  
              outStreamCoder);
  
  
  
  outStreamCoder.setNumPicturesInGroupOfPictures(12);
  
  outStreamCoder.setCodec(codec);
  
  outStreamCoder.setBitRate(videoSettings.getBitrate());
  
  outStreamCoder.setBitRateTolerance(videoSettings.getBitrateTolerance());
  
  outStreamCoder.setPixelType(IPixelFormat.Type.YUV420P);
  
  outStreamCoder.setHeight(videoSettings.getResolution().height);
  
  outStreamCoder.setWidth(videoSettings.getResolution().width);
  
  outStreamCoder.setFlag(IStreamCoder.Flags.FLAG_QSCALE, true);
  
  outStreamCoder.setGlobalQuality(0);
  
  fps = IRational.make((int) videoSettings.getFramerate(), 1);
  
  outStreamCoder.setFrameRate(fps);
  
  outStreamCoder.setTimeBase(IRational.make(fps.getDenominator(), fps.getNumerator()));

  which yields the following output :

  Codec: CODEC_ID_H264
  
  Resolution: 1280x720
  
  Bitrate: 25000
  
  Bitrate Tolerance: 1000
  
  Framerate: 25.0

  

  Now when I specify the MPEG4 codec, I get the following output :

  Codec: CODEC_ID_MPEG4
  
  Resolution: 1280x720
  
  Bitrate: 25000
  
  Bitrate Tolerance: 1000
  
  Framerate: 25.0

  

  As you can see, the only difference is the ICodec type (MPEG4 instead of H264) and the use of the preset (which is required by xuggler when using an H264 codec). Can anyone explain to me the huge difference in quality and tell me how to resolve the issue ?