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• FFMPEG Conversion improve quality

  1er octobre 2019, par user726720

  I have some questions regarding ffmpeg :

  I need to convert the XDCAM HD422 (yuv422p) to AVC (h.264, mp4). I’m doing it as follows :

  ffmpeg.exe -y -i path\abc.mxf  -ab 128k -acodec aac -ac 2 -strict -2 -b:v 12000k -f mp4 -g 34 -pix_fmt yuv420p -r 25 -s 1920x1080 -vcodec h264 -preset ultrafast h264file.mp4

  I have check the mp4 on a broadcast monitor and there are some visible color saturation issue’s. The quality doesn’t match the original XDCAM HD422

  1. What changes do I need to make in the above parameters to fix this ?
  2. My original file is a yuv422p and I’m using yuv420p in the above ffmpeg command, does this make a difference in the quality.
  3. Should change the preset from ultrafast to Fast make a difference.
  4. Will using the libx264 make any difference ?
  5. How does ffmeg encode from one format to another. Does it simply do a direct conversion or does it extract the RAW (yuv) from the XDCAM and then encode it into MP4 ?

  I’m just brainstorming how to improve the quality so it matches the that of XDCAM, any suggestions would be highly appreciated.

• configure : Don’t use symlinks for creating the out of tree makefile

  14 novembre 2013, par Martin Storsjö

  configure : Don’t use symlinks for creating the out of tree makefile
  On some platforms (such as msys), symlinks are (poorly) emulated
  
  by simply creating a copy of the file.
  This means that when building out of tree, the build tree gets
  
  a copy of the original makefile, which can lead to unintuitive
  
  build errors when the original makefile gets updated later.
  Instead simply create a stub makefile which includes the real
  
  one.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] configure

• How to get better video quality using Accord.Video.FFMPEG.DLL

  31 juillet 2023, par HighwayRob

  I have developed a Visual Studio Winapp that produces a video file utilizing Accord.Video.FFMPEG.DLL.

  


  The quality the video is less than the original images.
Here is the code and then a sample original image and snapshot of the resulting video.

  


  What can I change to improve the video image ?

  


              VideoFileWriter writer = new VideoFileWriter();
            writer.Open(outfile, width, height, 1, VideoCodec.Mpeg4);
            for (int i = firstrow; i <= testframes; i++)
            {
                Bitmap bitmap = new Bitmap(ffiles[i, 0].ToString());
                writer.WriteVideoFrame(bitmap);
                bitmap.Dispose();
            }


  


  I tried Bitmap image = new Bitmap(width, height, PixelFormat.Format64bppArgb) ;