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• avcodec/pngdec : Copy IHDR & plte state from last thread

  29 juin 2015, par Michael Niedermayer

  avcodec/pngdec : Copy IHDR & plte state from last thread
  Previously these chunks where parsed again for each frame with threads
  
  but not without leading to a different path and the potential for
  
  inconsistencies
  This also removes a related special case from decode_ihdr_chunk()
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/pngdec.c

• How do I simulate rtp (packet) loss simulation ?

  18 juin 2015, par Haroldy

  I previously used JM14.2 to see the cause and effect on the quality of yuv file by the number of slice, FMO, and etc. In the end, I want to increase robustness and resilience to YUV file.

  I encoded yuv file first, and then damage the 264 file with the provided simulation rtp_loss (JM14.2) with 5% loss of packets. and then I decoded the 264 file to see the result.

  Now I want to try similar simulation with ffmpeg. So I encoded video with this command

      ffmpeg -f rawvideo -s:v 352x288 -i akiyo.yuv -vcodec libx264 -preset slower -x264opts slice-max-size=150:bframes=1:keyint=20 -profile:v baseline -f rawvideo hi.264

  after I made hi.264 file, I tried to run rtp_loss (JM14.2) packet loss simulation, but I get an error.

  I wonder if there is ffmpeg command for rtp loss simulation. If there is, could you tell me how to use it ?
  Thanks

• JavaCV Error in Android

  18 juin 2015, par Gufran Khurshid

  It may be a previously asked related issue regarding JavaCV on Android.My main objective is to apply grayscale/other image effect on video.

  File sourceFile = new File(Environment.getExternalStorageDirectory()
  
              + File.separator + "test.mp4");
  
      FFmpegFrameGrabber ffg = new FFmpegFrameGrabber(sourceFile);
  
      OpenCVFrameConverter.ToIplImage converter = new     OpenCVFrameConverter.ToIplImage();
  
  
  
  
  
      try {
  
          ffg.start();
  
          int count = 0;
  
          while (true) {
  
              Log.d("JAVA_CV", "Counting . . . " + count);
  
  
  
              Frame original_frame = ffg.grab();
  
  
  
              if (original_frame == null) {
  
                  Log.d("JAVA_CV", "original_frame is NULL at" + count);
  
                  break;
  
              } else {
  
                  Log.d("JAVA_CV", "original_frame is NOT_NULL at" + count);
  
                  opencv_core.IplImage frame1 = converter.convert(original_frame);
  
                  opencv_core.IplImage frame2 = opencv_core.IplImage.create(original_frame.imageWidth, original_frame.imageHeight, opencv_core.IPL_DEPTH_8U, 1);
  
  
  
  
  
                  opencv_imgproc.cvCvtColor(frame1, frame2, opencv_imgproc.COLOR_RGB2GRAY);
  
  
  
              }
  
              count++;
  
          }
  
      } catch (FrameGrabber.Exception fe) {
  
          fe.printStackTrace();
  
          System.out.println(fe.getMessage());
  
      } catch (Exception e) {
  
          e.printStackTrace();
  
          System.out.println(e.getMessage());
  
      }
  
  }

  The exception has occured at line

   opencv_imgproc.cvCvtColor(frame1, frame2, opencv_imgproc.COLOR_RGB2GRAY);

  Exception Stack is showing :

   OpenCV Error: Assertion failed (scn == 3 || scn == 4) in void    cv::cvtColor(cv::InputArray, cv::OutputArray, int, int), file /home/saudet/projects/bytedeco/javacpp-presets/opencv/cppbuild/android-arm/opencv-2.4.11/modules/imgproc/src/color.cpp, line 3739

  My research states that the issue is with channels and target color, as stated here.Please tell me the where can I get color-channel sheet ? or some other alternate solution.