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• Why when creating a video file from images using ffmpeg when playing the video file the quality is bad and the video is running too fast ?

  27 avril 2016, par Daniel Voit

   public void Start(string pathFileName, int BitmapRate)
  
          {
  
              try
  
              {
  
  
  
                  string outPath = pathFileName;
  
                  p = new NamedPipeServerStream(pipename, PipeDirection.Out, 1, PipeTransmissionMode.Byte);
  
                  ProcessStartInfo psi = new ProcessStartInfo();
  
                  psi.WindowStyle = ProcessWindowStyle.Hidden;
  
                  psi.UseShellExecute = false;
  
                  psi.CreateNoWindow = false;
  
                  psi.FileName = ffmpegFileName;
  
                  psi.WorkingDirectory = workingDirectory;
  
                  psi.Arguments = @"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v libx264 -crf 20 -r " + BitmapRate + " " + outPath;
  
                      //@"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v mpeg2video -crf 20 -r " + BitmapRate + " " + outPath;
  
  
  
                  process = Process.Start(psi);
  
                  process.EnableRaisingEvents = false;
  
                  psi.RedirectStandardError = true;
  
                  p.WaitForConnection();
  
              }
  
              catch (Exception err)
  
              {
  
                  Logger.Write("Exception Error: " + err.ToString());
  
              }
  
          }

  I tried to use either the first or second line.
  BitmapRate is set to 25
  I tried to change both 20 to 10 and also the BitmapRate to 10 or to 17. but the video on hard disk when playing it it’s only 3-4 seconds bad quality.
  I see all the images but too fast it’s like running I forward mode.

  Each file size is 8MB on hard disk.
  55 Bitmap files.
  The video file is 1072 KB

  Tried to google but I didn’t find any googd example to fix it.
  It’s not that it’s not creating the video file it does but with bad quality and running too fast.

  It’s strange why the created video file is so small if every file is 8MB and why so bad quality.

  The video

  video

• Save two video streams in one video file c#, Windows 8 application [on hold]

  19 septembre 2014, par manos

  I am developing a Windows store application which will be able to record video from two video sources (e.g. two usb cameras or usb camera and embeded tablet camera) and then save the two video streams in one video file. So, when the saved video will play, it will show a large video frame (video from camera 1) and inside that, in the top right corner, a smaller video frame (video from camera 2). Basically, i want to render one video on top of the other. I think the process is called picture in picture, but I am not 100% sure. I am able two capture the 2 video streams (same length, same video quality) but I do not know how to proceed after that. How to do the rendering. Do I save the streams into two files and then process those files or do i need to process the streams directly (merge them) and then save to file ?
  I have read that you can do something like that by using ffmpeg libraries. But so far I have not managed to find any c# code to it. Any ideas ?

  Thanks in advance,
  Manos

• Is there any way to provide different video qualities in my web application without converting each video to each format ?

  15 octobre 2019, par Dheeraj Arora

  i am building a web application which will handle thousand of videos. Currently, I am using ffmpeg to convert each video to 4 formats(1080,720,480,340px). It consumes lot of memory and time to upload for each video. Is there any best way that allows user to stream my videos in different video quality without converting each video ?