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• FLutter : Read frames fom video, process it, put it to output video

  26 juin 2023, par RAITON

  I have video record and I need to process frames of this video, and for each frame/image write random integer on top left or right of image ( the random integer is only example I will replace this random int by my logic )

  


  something like :

  


  // 1. extract list of frames from video
// 2. process images/frames and add random integer in top left or right of image
// 3. Write output Video with new Frames contain the random integer 


  


  can someone help to have code example to resolve this by using ffmpeg package or any other package ?

  


  Thanks

  


• FFmpeg throwing error during video render process using Remotion

  31 mai 2022, par Vince

  I'm using a tool called Remotion, which allows you to create videos using javascript (node & react). I have the server-side rendering process working, unless I try to include an mp3. Per their docs, I have my audio imported like this :

  


  import goodtimes from &#x27;../../music/GoodTimes.mp3&#x27;;&#xA;&#xA;...&#xA;&#xA;<audio src="{goodtimes}"></audio>&#xA;

  


  I'm currently trying to troubleshoot this using the CLI, because the error messaging is better. The command runs, and seems to generate the full video – 2400 out of 2400 frames. But then it fails with this output :

  


  (2/3) [====================] Rendered frames (6x) 176540ms&#xA;    &#x2B; [====================] Downloading http://localhost:3000/1ba90857580e6291.mp3&#xA;(3/3) [====================] Encoding video 2400/2400&#xA;An error occurred:&#xA;Error: Command failed with exit code 1: ffprobe -v error -show_entries stream=channels:format=duration -of default=nw=1 /var/folders/6n/_nfb38t53dgdj092_pcnqqmw0000gn/T/remotion-assets-dir2jc2oppruh/7744374580215663.mp3&#xA;[mp3 @ 0x7fa78152ec40] Failed to read frame size: Could not seek to 5244.&#xA;/var/folders/6n/_nfb38t53dgdj092_pcnqqmw0000gn/T/remotion-assets-dir2jc2oppruh/7744374580215663.mp3: Invalid argument&#xA;    at makeError (/Users/voverson/clm-video/server/node_modules/execa/lib/error.js:60:11)&#xA;    at handlePromise (/Users/voverson/clm-video/server/node_modules/execa/index.js:118:26)&#xA;    at runMicrotasks (<anonymous>)&#xA;    at processTicksAndRejections (internal/process/task_queues.js:93:5)&#xA;    at async getAudioChannelsAndDuration (/Users/voverson/clm-video/server/node_modules/@remotion/renderer/dist/assets/get-audio-channels.js:17:18)&#xA;    at async preprocessAudioTrackUnlimited (/Users/voverson/clm-video/server/node_modules/@remotion/renderer/dist/preprocess-audio-track.js:14:36)&#xA;</anonymous>

  


  I'm hoping some ffmpeg experts might recognize this error and have some idea what might be causing it.

  


• Faster way to write image to Process.StandardInput.BaseStream

  4 septembre 2012, par Hasibii

  Im trying to send a lot of desktop captured images to an encoders (FFmpeg) stdin.

  The following code example works.

  the CaptureScreen() function provides an image in 5-10 ms.

  If I save the image in a MemoryStream it takes almost no time.

  But I can only save 1 image every 45 ms to
  proc.StandardInput.BaseStream.

  public void Start(string bitrate, string buffer, string fps, string rtmp, string resolution, string preset)
  
  {
  
      proc.StartInfo.FileName = myPath + "\\ffmpeg.exe";
  
      proc.StartInfo.Arguments = "-f image2pipe -i pipe:.bmp -vcodec libx264 -preset " + preset + " -maxrate " + bitrate + "k -bufsize " +
  
      buffer + "k -bt 10 -r " + fps + " -an -y test.avi"; //+ rtmp;
  
      proc.StartInfo.UseShellExecute = false;
  
      proc.StartInfo.RedirectStandardInput = true;
  
      proc.StartInfo.RedirectStandardOutput = true;
  
  
  
      proc.Start();
  
  
  
      Stopwatch st = new Stopwatch();
  
      BinaryWriter writer = new BinaryWriter(proc.StandardInput.BaseStream);
  
      System.Drawing.Image img;
  
  
  
      st.Reset();
  
      st.Start();
  
  
  
      for (int z = 0; z < 100; z++)
  
      {
  
          img = ScrCap.CaptureScreen();
  
          img.Save(writer.BaseStream, System.Drawing.Imaging.ImageFormat.Bmp);
  
          img.Dispose();
  
      }
  
  
  
      st.Stop();
  
      System.Windows.Forms.MessageBox.Show(st.ElapsedMilliseconds.ToString());
  
  }

  The question is :

  Can I do the saving process faster ?

  I try to get stable 60 fps this way