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• Ffmpeg only receives a piece of information from the pipe

  4 juillet 2017, par Maxim Fedorov

  First of all - my english is not very good, i`m sorry for that.

  I use ffmpeg from c# to convert images to video. To interact with ffmpeg, I use pipes.

  public async Task ExecuteCommand(
  
          string arguments,
  
          Action<namedpipeserverstream> sendDataUsingPipe)
  
      {
  
          var inStream = new NamedPipeServerStream(
  
              "from_ffmpeg",
  
              PipeDirection.In,
  
              1,
  
              PipeTransmissionMode.Byte,
  
              PipeOptions.Asynchronous,
  
              PipeBufferSize,
  
              PipeBufferSize);
  
  
  
          var outStream = new NamedPipeServerStream(
  
              "to_ffmpeg",
  
              PipeDirection.Out,
  
              1,
  
              PipeTransmissionMode.Byte,
  
              PipeOptions.Asynchronous,
  
              PipeBufferSize,
  
              PipeBufferSize);
  
  
  
          var waitInConnectionTask = inStream.WaitForConnectionAsync();
  
          var waitOutConnectionTask = outStream.WaitForConnectionAsync();
  
  
  
          byte[] byteData;
  
  
  
          using (inStream)
  
          using (outStream)
  
          using (var inStreamReader = new StreamReader(inStream))
  
          using (var process = new Process())
  
          {
  
              process.StartInfo = new ProcessStartInfo
  
              {
  
                  RedirectStandardOutput = true,
  
                  RedirectStandardError = true,
  
                  RedirectStandardInput = true,
  
                  FileName = PathToFfmpeg,
  
                  Arguments = arguments,
  
                  UseShellExecute = false,
  
                  CreateNoWindow = true
  
              };
  
  
  
              process.Start();
  
  
  
              await waitOutConnectionTask;
  
  
  
              sendDataUsingPipe.Invoke(outStream);
  
  
  
              outStream.Disconnect();
  
              outStream.Close();
  
  
  
              await waitInConnectionTask;
  
  
  
              var logTask = Task.Run(() => process.StandardError.ReadToEnd());
  
              var dataBuf = ReadAll(inStream);
  
  
  
              var shouldBeEmpty = inStreamReader.ReadToEnd();
  
              if (!string.IsNullOrEmpty(shouldBeEmpty))
  
                  throw new Exception();
  
  
  
              var processExitTask = Task.Run(() => process.WaitForExit());
  
              await Task.WhenAny(logTask, processExitTask);
  
              var log = logTask.Result;
  
  
  
              byteData = dataBuf;
  
  
  
              process.Close();
  
              inStream.Disconnect();
  
              inStream.Close();
  
          }
  
  
  
          return byteData;
  
      }
  
  </namedpipeserverstream>

  Action "sendDataUsingPipe" looks like

  Action<namedpipeserverstream> sendDataUsingPipe = stream =>
  
          {
  
              foreach (var imageBytes in data)
  
              {
  
                  using (var image = Image.FromStream(new MemoryStream(imageBytes)))
  
                  {
  
                      image.Save(stream, ImageFormat.Jpeg);
  
                  }
  
              }
  
          };
  
  </namedpipeserverstream>

  When I send 10/20/30 images (regardless of the size) ffmpeg processes everything.
  When I needed to transfer 600/700 / .. images, then in the ffmpeg log I see that it only received 189-192, and in the video there are also only 189-192 images.
  There are no errors in the logs or exceptions in the code.

  What could be the reason for this behavior ?

• Java Xuggler Metadata List of Chapters MP4/M4V Video

  27 juin 2017, par MrSax

  I’m trying to use Xuggler like FFMPEG Metadata Wrapper (I just need the list of Chapters of MP4/M4V Video).

  So far I have not been able to find a solution.
  Can anyone help me ?

  I was only able to get the following information :

      final String filename = "...path...";
  
      IContainer container = IContainer.make();
  
      int result = container.open(filename, IContainer.Type.READ, null);
  
      if (result < 0)
  
          throw new RuntimeException("Failed to open media file");
  
      int numStreams = container.getNumStreams();
  
      long duration = container.getDuration();
  
      long fileSize = container.getFileSize();
  
      long bitRate = container.getBitRate();
  
      System.out.println("Number of streams: " + numStreams);
  
      System.out.println("Duration (ms): " + duration);
  
      System.out.println("File Size (bytes): " + fileSize);
  
      System.out.println("Bit Rate: " + bitRate);
  
      for (int i = 0; i < numStreams; i++) {
  
          IStream stream = container.getStream(i);
  
          IStreamCoder coder = stream.getStreamCoder();
  
          System.out.println("*** Start of Stream Info ***");
  
          System.out.printf("stream %d: ", i);
  
          System.out.printf("type: %s; ", coder.getCodecType());
  
          System.out.printf("codec: %s; ", coder.getCodecID());
  
          System.out.printf("duration: %s; ", stream.getDuration());
  
          System.out.printf("start time: %s; ", container.getStartTime());
  
          System.out.printf("timebase: %d/%d; ", stream.getTimeBase().getNumerator(),
  
                  stream.getTimeBase().getDenominator());
  
          System.out.printf("coder tb: %d/%d; ", coder.getTimeBase().getNumerator(),
  
                  coder.getTimeBase().getDenominator());
  
          System.out.println();
  
          if (coder.getCodecType() == ICodec.Type.CODEC_TYPE_AUDIO) {
  
              System.out.printf("sample rate: %d; ", coder.getSampleRate());
  
              System.out.printf("channels: %d; ", coder.getChannels());
  
              System.out.printf("format: %s", coder.getSampleFormat());
  
          } else if (coder.getCodecType() == ICodec.Type.CODEC_TYPE_VIDEO) {
  
              System.out.printf("width: %d; ", coder.getWidth());
  
              System.out.printf("height: %d; ", coder.getHeight());
  
              System.out.printf("format: %s; ", coder.getPixelType());
  
              System.out.printf("frame-rate: %5.2f; ", coder.getFrameRate().getDouble());
  
          }
  
          System.out.println();
  
          System.out.println("*** End of Stream Info ***");

  UPDATE 07.06.2017
  I just tried it with VLCJ, but still I can not get the list of chapters.

      File file = new File("ia_ISL_13_r720P.m4v");
  
  
  
      NativeLibrary.addSearchPath(RuntimeUtil.getLibVlcLibraryName(), "vlc64/");
  
      Native.loadLibrary(RuntimeUtil.getLibVlcLibraryName(), LibVlc.class);
  
  
  
      MediaPlayerFactory mpf = new MediaPlayerFactory();
  
      EmbeddedMediaPlayer emp = mpf.newEmbeddedMediaPlayer();
  
  
  
      MediaMeta mediaMeta = mpf.getMediaMeta(file.getAbsolutePath(), true);
  
      MediaMetaData asMediaMetaData = mediaMeta.asMediaMetaData();
  
      System.out.println(asMediaMetaData.getAlbum());
  
      System.out.println(asMediaMetaData.getArtist());
  
      System.out.println(asMediaMetaData.getTitle());
  
  
  
      emp.prepareMedia(file.getAbsolutePath());
  
      emp.play();
  
      emp.nextChapter(); // -> GO NEXT CHAPTER - SUCCESS
  
  
  
      List> allChapterDescriptions = emp.getAllChapterDescriptions();
  
  
  
      for (List<string> list : allChapterDescriptions) {
  
          for (String string : list) {
  
              System.out.println(string);
  
          }
  
      }
  
  </string>

• ValueError When Reading Video Frame

  28 juin 2017, par Bassie

  I am following this article, from where I got this code :

  FFMPEG_BIN ="Z:\ffmpeg\bin\ffmpeg.exe"
  
  
  
  import subprocess as sp
  
  command = [ FFMPEG_BIN,
  
              '-i', 'video.mp4',
  
              '-f', 'image2pipe',
  
              '-pix_fmt', 'rgb24',
  
              '-vcodec', 'rawvideo', '-']
  
  pipe = sp.Popen(command, stdout = sp.PIPE, bufsize=10**8, shell=True)
  
  
  
  import numpy
  
  # read 420*360*3 bytes (= 1 frame)
  
  raw_image = pipe.stdout.read(420*360*3)
  
  # transform the byte read into a numpy array
  
  image =  numpy.fromstring(raw_image, dtype='uint8')
  
  image = image.reshape((360,420,3))
  
  # throw away the data in the pipe's buffer.
  
  pipe.stdout.flush()

  When I run it I see this error :

  Traceback (most recent call last):
  
    File "Z:\py\ffmtest\test.py", line 16, in <module>
  
      image = image.reshape((360,420,3))
  
  ValueError: total size of new array must be unchanged
  
  </module>

  Where line 16 is image = image.reshape((360,420,3)). I think this error is produced by numpy, but probably because I am calculating the values for my video incorrectly.

  Output :

  raw_image : b’ ’

  len(raw_image) : 0

  image : [ ]

  len(image) : 0

  I am not sure whether I am passing in the correct values for read or reshape functions - any help at all is much appreciated !