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• Reducing FFMPEG h264 video stream latency

  5 juin 2016, par KKKk

  I’m using FFMPEG(h264) and I want to reduce latency as much as possible. Now it’s about 700 ms and I can’t really make it lower. I tried almost all, so maybe anyone has idea how to help me ?

  ffmpeg -f dshow -i video="screen-capture-recorder" -pix_fmt yuv420p -probesize 32 -r 100 -an -vcodec libx264 -crf 40 -preset ultrafast -tune zerolatency -threads 8 -thread_type slice -f mpegts udp://192.168.88.228:1234

  The weird thing is I got this latency even on 127.0.0.1....
  (on the other side I use just ffplay udp :// .......)

• Surface Texture object is not getting the frames from a Surface Class

  22 avril 2016, par Juan Manuel González Otero

  On the one hand, I have a Surface Class which when instantiated, automatically initialize a new thread and start grabbing frames from a streaming source via native code based on FFMPEG. Here is the main parts of the code for the aforementioned Surface Class :

   public class StreamingSurface extends Surface implements Runnable {
  
  
  
      ...
  
  
  
      public StreamingSurface(SurfaceTexture surfaceTexture, int width, int height) {
  
          super(surfaceTexture);
  
  
  
          screenWidth  = width;
  
          screenHeight = height;      
  
          init();
  
  
  
      }
  
  
  
      public void init() {
  
          mDrawTop = 0;
  
          mDrawLeft = 0;
  
          mVideoCurrentFrame = 0;
  
          this.setVideoFile();
  
          this.startPlay();
  
      }
  
  
  
      public void setVideoFile() {        
  
          // Initialise FFMPEG
  
          naInit("");
  
  
  
          // Get stream video res
  
          int[] res = naGetVideoRes();
  
          mDisplayWidth = (int)(res[0]);
  
          mDisplayHeight = (int)(res[1]);
  
  
  
          // Prepare Display
  
          mBitmap = Bitmap.createBitmap(mDisplayWidth, mDisplayHeight, Bitmap.Config.ARGB_8888);
  
          naPrepareDisplay(mBitmap, mDisplayWidth, mDisplayHeight);
  
      }
  
  
  
      public void startPlay() {
  
          thread = new Thread(this);
  
          thread.start(); 
  
      }
  
  
  
      @Override
  
      public void run() {
  
          while (true) {
  
              while (2 == mStatus) {
  
                  //pause
  
                  SystemClock.sleep(100);
  
              }
  
              mVideoCurrentFrame = naGetVideoFrame();
  
              if (0 < mVideoCurrentFrame) {
  
                  //success, redraw
  
                  if(isValid()){
  
                       Canvas canvas = lockCanvas(null);
  
                       if (null != mBitmap) {
  
                           canvas.drawBitmap(mBitmap, mDrawLeft, mDrawTop, prFramePaint);
  
                       }
  
                       unlockCanvasAndPost(canvas);
  
                  }
  
              } else {
  
                  //failure, probably end of video, break
  
                  naFinish(mBitmap);
  
                  mStatus = 0;
  
                  break;
  
              }
  
          }   
  
      }
  
  
  
  }

  In my MainActivity class, I instantiated this class in the following way :

  public void startCamera(int texture)
  
  {
  
      mSurface = new SurfaceTexture(texture);
  
      mSurface.setOnFrameAvailableListener(this); 
  
      Surface surface = new StreamingSurface(mSurface, 640, 360);
  
      surface.release();        
  
  }

  I read the following line in the Android developer page, regarding the Surface class constructor :

  "Images drawn to the Surface will be made available to the SurfaceTexture, which can attach them to an OpenGL ES texture via updateTexImage()."

  That is exactly what I want to do, and I have everything ready for the further renderization. But definitely, with the above code, I never get my frames captured in the surface class transformed to its corresponding SurfaceTexture. I know this because the debugger, for instace, never call the OnFrameAvailableLister method associated with that Surface Texture.

  Any ideas ? Maybe the fact that I am using a thread to call the drawing functions is messing everything ? In such a case, what alternatives I have to grab the frames ?

  Thanks in advance

• ffmpeg from a C# app using Process class - user prompt not shown in standardError

  21 avril 2016, par DarwinIcesurfer

  I am writing an app to run ffmpeg using c#. My program redirects the standardError output to a stream so it can be parsed for progress information.

  During testing I have found a problem :

  If the output is shown in a command window rather than being redirected ffmpeg will display it’s normal headers followed by "file c :\temp\testfile.mpg already exists. overwrite [y]". If I click on the command window and press y the program continues to encode the file.

  If the StandardError is redirected to my handler and then printed to the console, I see the same header information that was displayed in the command window now printed to the console. except for the file...already exists prompt. If I click in the command window and press y the program continues to process the file.

  Is there a stream other than standardOutput or standardError that is used when the operator is prompted for information, or am I missing something else ?

  public void EncodeVideoWithProgress(string filename, string arguments, BackgroundWorker worker, DoWorkEventArgs e)
  
      {
  
  
  
          Process proc = new Process();
  
  
  
          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 = false; //set to true for testing
  
  
  
          proc.ErrorDataReceived += new DataReceivedEventHandler(NetErrorDataHandler);
  
  
  
          proc.Start();
  
          proc.BeginErrorReadLine();
  
  
  
  
  
          StreamReader reader = proc.StandardOutput;
  
           string line;
  
           while ((line = reader.ReadLine()) != null)
  
          { Console.WriteLine(line); }
  
       proc.WaitForExit();
  
  }
  
  
  
  private static void NetErrorDataHandler(object sendingProcess,
  
                 DataReceivedEventArgs errLine)
  
      {
  
          if (!String.IsNullOrEmpty(errLine.Data))
  
          {
  
              Console.WriteLine(errLine.Data);
  
          }
  
      }