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• ffserver : local OOB write with custom program name

  6 janvier 2017, par Tobias Stoeckmann

  ffserver : local OOB write with custom program name
  When the command line for children is created, it is assumed that
  
  my_program_name always ends with "ffserver", which doesn’t have to
  
  be true if ffserver is called through a symbolic link.
  In such a case, it could be that not enough space for "ffmpeg" is
  
  available at the end, leading to a buffer overflow.
  One example would be :
  $ ln -s /usr/bin/ffserver /f ; /f
  As this is only a local buffer overflow, i.e. is based on a weird
  
  program call, this has NO security impact.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] ffserver.c

• different results in different environments (AWS Lambda vs Local) using the same ffmpeg command

  21 mars 2017, par bitterman

  I am getting to my wit’s end here. So I have an AWS lambda that is just some Java code that runs an ffmpeg command on a video file. When I download this video file and ffprobe it, the metadata looks different from what it looks like when I grab the same file and run the same ffmpeg command locally from the command line. I have no idea why this is. I made sure to have the same ffmpeg versions and all, but the file resulting from the lambda running the command is missing things compared to the other one. The reason I’m looking at this is the fact that this file resulting from the lambda running the command is not playable on certain players (has issues with android exoplayer and the android/mobile version of Chrome, for instance) while the one resulting from me running the command is playable everywhere that I’ve tried. Here are the different metadatas :

  As run locally :

  Metadata:
  
    service_name    : Service01
  
    service_provider: FFmpeg
  
  Stream #0:0[0x100]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, progressive), 1280x720 [SAR 1:1 DAR 16:9], 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
  
  Stream #0:1[0x101]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 95 kb/s

  vs as run by the lambda :

  Metadata:
  
    service_name    : Service01
  
    service_provider: FFmpeg
  
  Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 1280x720, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
  
  Stream #0:1[0x101]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp, 95 kb/s

  As you can see, one has DAR and SAR explicitly stated next to the resolution and also has "tv" next to progressive in parentheses next to yuv420p. I’ve tried tweaking the command by adding more filters and flags, but the end result is the same... I’m not sure this would fix my playability issue, but could someone explay why the end results are different despite using the same version (and both are 64 bit) of ffmpeg and all ?

• Android JavaCV FFmpeg webstream to local static website

  26 mars 2017, par Thomas Devoogdt

  For my integrated test I’m working on an application that needs to provide a live stream to a locally hosted website. I’ve already built a working site that run’s on nanohttpd. This application performs also special image processing. Therefore I use JavaCV. The library is working perfectly and all cpp bindings are working too.

  My question : How to set up a live stream that can directly be played in a static site hosted by nanohttpd ? - I am on the right way ?

  My code :

  init :

  private void initLiveStream() throws FrameRecorder.Exception {
  
      /* ~~~ https://github.com/bytedeco/javacv/issues/598 ~~~ */
  
      frameRecorder = new FFmpegFrameRecorder("http://localhost:9090", imageWidth, imageHeight, 0);
  
      frameRecorder.setVideoOption("preset", "ultrafast");
  
      frameRecorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);
  
      frameRecorder.setAudioCodec(0);
  
      frameRecorder.setPixelFormat(avutil.AV_PIX_FMT_YUV420P);
  
      frameRecorder.setFormat("webm");
  
      frameRecorder.setGopSize(10);
  
      frameRecorder.setFrameRate(frameRate);
  
      frameRecorder.setVideoBitrate(5000);
  
      frameRecorder.setOption("content_type","video/webm");
  
      frameRecorder.setOption("listen", "1");
  
      frameRecorder.start();
  
  }

  In my CameraView :

  @Override
  
  public void onPreviewFrame(byte[] data, Camera camera) {
  
      Camera.Size size = camera.getParameters().getPreviewSize();
  
      Frame frame = new AndroidFrameConverter().convert(data, size.width, size.height);
  
      try {
  
           if(frameRecorder!=null){
  
               frameRecorder.record(frame);
  
           }
  
       } catch (FrameRecorder.Exception e) {
  
           e.printStackTrace();
  
       }
  
   }

  Here is one of the stack traces that ar shown frequently in my search to the solution :

  org.bytedeco.javacv.FrameRecorder$Exception: avio_open error() error -111: Could not open 'http://localhost:9090'

  I couldn’t find any other thread addressing this specific issue.

  Thanks in advance

  EDIT

  Thanks to Chester Cobus, Here is my used code :

  Websocket :

  //Constructor
  
  AsyncHttpServer serverStream = new AsyncHttpServer();
  
  List<websocket> sockets = new ArrayList&lt;>();
  
  
  
  //http://stackoverflow.com/a/33021907/5500092
  
  //I'm planning to use more sockets. This is the only uniform expression I found.
  
  serverStream.websocket("/((?:[^/]*/)*)(.*)", new AsyncHttpServer.WebSocketRequestCallback() {
  
       @Override
  
       public void onConnected(final WebSocket webSocket, AsyncHttpServerRequest request) {
  
           String uri = request.getPath();
  
           if (uri.equals("/live")) {
  
               sockets.add(webSocket);
  
  
  
               //Use this to clean up any references to your websocket
  
               webSocket.setClosedCallback(new CompletedCallback() {
  
                   @Override
  
                   public void onCompleted(Exception ex) {
  
                       try {
  
                           if (ex != null)
  
                               Log.e("WebSocket", "Error");
  
                       } finally {
  
                           sockets.remove(webSocket);
  
                       }
  
                   }
  
               });
  
           }
  
       }
  
  });
  
  
  
  //Updater (Observer pattern)
  
  @Override
  
  public void updated(byte[] data) {
  
      for (WebSocket socket : sockets) {
  
           socket.write(new ByteBufferList(data));
  
      }
  
  }
  
  </websocket>

  Record Acitivy

  private long start_time = System.currentTimeMillis();
  
  
  
  @Override
  
  public void onPreviewFrame(byte[] data, Camera camera) {
  
      long now_time = System.currentTimeMillis();
  
      if ((now_time - start_time) > 250) {
  
          start_time = now_time;
  
          //https://forums.xamarin.com/discussion/40991/onpreviewframe-issue-converting-preview-byte-to-android-graphics-bitmap
  
          Camera.Size size = camera.getParameters().getPreviewSize();
  
          YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);
  
          ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
  
          image.compressToJpeg(new Rect(0, 0, size.width, size.height), 60, byteArrayOutputStream);
  
          MainActivity.getWebStreamer().updated(byteArrayOutputStream.toByteArray());
  
      }
  
  }

  JavaScript

  var socket;
  
  var imageElement;
  
  
  
  /**
  
   * path - String.Format("ws://{0}:8090/live", Window.Location.HostName)
  
   * image - HTMLImageElement
  
   */
  
  function imageStreamer(path, image) {
  
      imageElement = image;
  
      socket = new WebSocket(path);
  
  
  
      socket.onmessage = function(msg) {
  
          var arrayBuffer = msg.data;
  
          var reader = new FileReader();
  
          reader.onload = function(e) {
  
              imageElement.src = e.target.result;
  
          };
  
          reader.readAsDataURL(arrayBuffer);
  
      };
  
  }