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• Create muted video and black screen video with FFmpeg

  2 mars 2021, par user2685832

  I'm trying to use FFmpeg to generate the following from a local mp4 file :

  



  

  • A copy of the original video with no audio

  


  • A copy of the original video with audio but without visuals (a black screen instead). This file also needs to be in mp4 format.

  


  



  After reading through the documentation I am struggling to get the terminal commands right. To remove the audio I have tried this command without any success :

  



  ffmpeg -i file.mp4 -map 0:0 -map 0:2 -acodec copy -vcodec copy


  



  Could anyone guide me towards how to accomplish this ?

  


• Extract audio and video frames from a video [on hold]

  27 avril 2014, par zeitgeist

  I tried to extract video frames using Aforge FFMPEG. But it is quite slow and extracts video quailty is low. Also it doesn’t support audio functionality. So I need a library that would be extracting its audio and quality video frames.

  Below code is extracted video frames.

          VideoFileReader reader = new VideoFileReader();
  
          VideoFileWriter writer = new VideoFileWriter();
  
          reader.Open(@"D:\Ali\Videos\katy.mp4");
  
          writer.Open( @"D:\Ali\Videos\katy_.mp4", reader.Width, reader.Height, reader.FrameRate, VideoCodec.MPEG4 );
  
          Bitmap videoFrame;
  
          while((videoFrame = reader.ReadVideoFrame()) !=null )
  
          {
  
              writer.WriteVideoFrame(videoFrame);
  
              // dispose the frame when it is no longer required
  
              videoFrame.Dispose();
  
          }

• Accord.Video.FFMPEG getting error for long video

  30 novembre 2022, par wahyu

  I use Accord.Video.FFMPEG to extract images every 10 frames from a video. Total frames for this video is 38194 frames. First run is good, I can save image every 10 frames but after run of about 38185 frames i got null return from this code Bitmap bmpBaseOriginal = vReader.ReadVideoFrame();, if I see in the video there is no problem at the end of video.

  


  I do something like this

  


  using (var vReader = new VideoFileReader())
{
    vReader.Open(files[0]);
    TotalFrame = vReader.FrameCount;
    countin = Convert.ToInt32(TotalFrame / Convert.ToDouble(countAsset));
    Fps = vReader.FrameRate.Value;                                
    int a = 0;
    for (int i = 0; i < vReader.FrameCount; i++)
    {
         if(i < vReader.FrameCount - 1)
         {
              Bitmap bmpBaseOriginal = vReader.ReadVideoFrame();
              if (i%10 == 0)
              {
                  a++;
                  bmpBaseOriginal.Save(string.Format("{0}\\{1}.jpeg", dirVideo.FullName, a), ImageFormat.Jpeg);
              }
              bmpBaseOriginal.Dispose();
         }
         else
         {
              a++;
              Bitmap bmpBaseOriginal = vReader.ReadVideoFrame();
              bmpBaseOriginal.Save(string.Format("{0}\\{1}.jpeg", dirVideo.FullName, a), ImageFormat.Jpeg);
              bmpBaseOriginal.Dispose();
         }
    }
    vReader.Close();
}


  


  this problem occurs again on another video if the video has a lot of frames, but no problem if the video has a less frames.

  


  How to solve it ?