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• Cancelling ffpeg launched as a C# process

  22 April 2016, by DarwinIcesurfer

  I’m launching ffmpeg in a c# process to encode a video. In a command window, ffmpeg can be interrupted by pressing CTRL-C. I have tried to achieve the same effect by closing the process, however ffmpeg does not appear to close (it is still visible in task manager and it does not release the handle on the file it was encoding)

  How can ffmpeg be interrupted programatically?

  static Process proc;
  
  static BackgroundWorker bw;     
  
  
  
  public void EncodeVideoWithProgress(string filename, string arguments, BackgroundWorker worker, DoWorkEventArgs e)
  
  {
  
      proc = new Process();
  
  
  
      // assign the backgroud worker to a class member variable so all function within the class will have access
  
      bw = worker;
  
  
  
      proc.StartInfo.FileName = "ffmpeg";
  
      proc.StartInfo.Arguments = "-i " + " \"" + filename + "\" " + arguments;
  
  
  
      proc.StartInfo.UseShellExecute = false;
  
      proc.EnableRaisingEvents = true;
  
      proc.StartInfo.RedirectStandardError = true;
  
      proc.StartInfo.RedirectStandardOutput = false;
  
      proc.StartInfo.CreateNoWindow = true;
  
  
  
      proc.ErrorDataReceived += new DataReceivedEventHandler(NetErrorDataHandler);
  
  
  
      proc.Start();
  
      proc.BeginErrorReadLine();
  
  
  
      proc.WaitForExit();
  
  }
  
  
  
  private static void NetErrorDataHandler(object sendingProcess,
  
             DataReceivedEventArgs errLine)
  
  {
  
      if (bw.CancellationPending)
  
      {
  
          proc.CloseMainWindow();
  
          proc.Close();   
  
      }
  
      else 
  
      {
  
       // do other tasks
  
      }
  
  }

• Properly handling FFMpeg multithreading

  31 March 2020, by Salvo Passaro

  I’m writing a program that receives multiple RTSP live streams and transmuxes them into various formats. My first idea was to spawn a thread for each stream to handle receiving, demuxing and remuxing; then i realized it was conceptually better to instead spread the work across "workers".

  So i eventually ended up building

  • a std::queue (and an associated mutex) of AVPackets for each stream
  • a semaphore based on std::condition_variable
  • a worker to handle network io (which essentially loops over av_read_frame and notifies the semaphore on each successful iteration)
  • a worker to "consume" received packets from the queue (which waits on the semaphore)

  Now, using the above, stream quality noticeably dropped. I’m not sure if my load balancing approach is poor or messes up libavformat somehow; is there something I’m missing?

• convert recordRTC webm file to mp4

  29 August 2022, by SAMEER

  I'm using recordRTC in browser for creating Video Clip, but after stop recording, I'm getting blob file type.

  


  but I want to mp4 file type, for converting I used ffmpeg.js https://archive.org/download/ffmpeg_asm/ffmpeg_asm.js . yes I'm able to covert it now,

  


  but the worry thing is, Now I only can view it on after downloading to my local PC, when I upload it to the server and then retrieve it, It's not visible.

  


  recordRef.current.stopRecording(function (url) {
        convertStreams(recordRef.current.getBlob());

      });


      var workerPath = 'https://archive.org/download/ffmpeg_asm/ffmpeg_asm.js';

      function processInWebWorker() {
        var blob = URL.createObjectURL(new Blob(['importScripts("' + workerPath + '");var now = Date.now;function print(text) {postMessage({"type" : "stdout","data" : text});};onmessage = function(event) {var message = event.data;if (message.type === "command") {var Module = {print: print,printErr: print,files: message.files || [],arguments: message.arguments || [],TOTAL_MEMORY: message.TOTAL_MEMORY || false};postMessage({"type" : "start","data" : Module.arguments.join(" ")});postMessage({"type" : "stdout","data" : "Received command: " +Module.arguments.join(" ") +((Module.TOTAL_MEMORY) ? ".  Processing with " + Module.TOTAL_MEMORY + " bits." : "")});var time = now();var result = ffmpeg_run(Module);var totalTime = now() - time;postMessage({"type" : "stdout","data" : "Finished processing (took " + totalTime + "ms)"});postMessage({"type" : "done","data" : result,"time" : totalTime});}};postMessage({"type" : "ready"});'], {
          type: 'application/javascript'
        }));

        var worker = new Worker(blob);
        URL.revokeObjectURL(blob);
        return worker;
      }

      var worker;

      function convertStreams(videoBlob) {
        setBlob(videoBlob)
        setIsRecording(false)
        setVideoPreview(true)
        var aab;
        var buffersReady;
        var workerReady;
        var posted;

        var fileReader = new FileReader();
        fileReader.onload = function () {
          aab = this.result;
          postMessage();
        };
        fileReader.readAsArrayBuffer(videoBlob);

        if (!worker) {
          worker = processInWebWorker();
        }

        worker.onmessage = function (event) {
          var message = event.data;
          if (message.type == "ready") {

            workerReady = true;
            if (buffersReady)
              postMessage();
          } else if (message.type == "stdout") {
          } else if (message.type == "start") {
          } else if (message.type == "done") {
            var result = message.data[0];
            var videoFile = new File([result.data], 'test.mp4', {
              type: 'video/mpeg4'
            });
            setVideo_obj(videoFile)


          }
        };
        const postMessage = function () {
          posted = true;

          worker.postMessage({
            type: 'command',
            arguments: '-i video.webm -c:v mpeg4 -b:v 6400k -strict experimental output.mp4'.split(' '),
            // arguments: 'ffmpeg -i video.webm -movflags faststart -profile:v high -level 4.2 video.mp4',
            files: [
              {
                data: new Uint8Array(aab),
                name: 'video.webm'
              }
            ]
          });

        };
      }


    }
  }