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• how to compile FFMPEG and merge it to one android ".so" file

  5 avril 2016, par user965347

  i am intereseted to compile the ffmpeg source to android to be invoked with jni as one ".so" last time i tried 0.8 versions but failed it always shows that something is undeclared, i tried all of google examples but it seems doesnt work for me,
  i tried this one

  Link One

  but it seems that the ffmpeg.c is not included with compile , but when i compile it always error, it says that something undeclared, and i cant build this project as one android ".so" file

  i also tried this one,
  Link Two

  but it seems i cant understand.

  i have tried everything , but none of them work ,none of them merge all ".o" , ".so" , ".a" into one ".so" files

  is there any good example in google or somewhere to compile ffmpeg as one ".so" file and have a good downloadable source i can compile ?

• Output pad "default" with type audio of the filter instance "Parsed_anull_0"

  13 octobre 2018, par CoXier

  I am using FFmpeg on my mobile device. I use below command to cut up input video.

   ffmpeg -i input.mp4 -ss start -t duration -y output.mp4

  But it crashes.

  Output pad "default" with type audio of the filter instance "Parsed_anull_0" of anull not connected to any destination
  Error reinitializing filters !
  Failed to inject frame into filter network : Invalid argument

  Is there any config need to be enable ?

  Thanks in advance.

• "Could not demultiplex stream" in loading Video recorded by Opencv's VideoWriter

  16 juin 2016, par batuman

  My program is

  int main(){
  
      cout << "Start the process" << endl;
  
      cv::VideoCapture vcap("rtsp://root:pass@192.168.0.90/axis-media/media.amp?camera=1");
  
      cout << "Camera connection done!" << endl;
  
      cv::Mat image, small;
  
      //Output video
  
      cv::Size S = cv::Size((int) vcap.get(CV_CAP_PROP_FRAME_WIDTH), (int) vcap.get(CV_CAP_PROP_FRAME_HEIGHT));
  
      int ex = static_cast<int>(vcap.get(CV_CAP_PROP_FOURCC));
  
      int fps = vcap.get(CV_CAP_PROP_FPS);
  
      cout &lt;&lt; "fps " &lt;&lt; fps &lt;&lt; " ex " &lt;&lt; ex &lt;&lt; endl;
  
      cv::VideoWriter outputVideo;
  
      outputVideo.open("TEST.avi", ex/*CV_FOURCC('X', '2', '6', '4')*/, vcap.get(CV_CAP_PROP_FPS), S, true);
  
      if(!outputVideo.isOpened()){
  
          cout &lt;&lt; "Could not open the output video for write" &lt;&lt; endl;
  
          return -1;
  
      }
  
  
  
      for(;;){
  
          if(!vcap.read(image)){
  
              std::cout &lt;&lt; "No frame" &lt;&lt; std::endl;
  
              cv::waitKey(0);
  
          }
  
  
  
          cv::resize(image, small, image.size()/2, 0, 0 , cv::INTER_LINEAR);
  
          cv::imshow("Display", small);
  
          cv::waitKey(1);
  
          outputVideo.write(small);
  
          if(getkey() == '\n')
  
              break;
  
      }
  
      cout &lt;&lt; "Camera release" &lt;&lt; endl;
  
      outputVideo.release();
  
      vcap.release();
  
      image.release();
  
      small.release();
  
      return 0;
  
  }
  
  </int>

  int ex = static_cast<int>(vcap.get(CV_CAP_PROP_FOURCC));</int> ex is 0 here.

  I can record the TEST.avi, but can’t be read by cv::VideoCapture vcap("TEST.avi") ; or VLC player or Videos in Ubuntu.
  The error is "Could not demultiplex stream".

  If I changed to

  outputVideo.open("TEST.avi", CV_FOURCC('X', '2', '6', '4'), vcap.get(CV_CAP_PROP_FPS), S, true);
  
  outputVideo.open("TEST.avi", CV_FOURCC('P','I','M','1'), vcap.get(CV_CAP_PROP_FPS), S, true);
  
  outputVideo.open("TEST.avi", CV_FOURCC('M', 'P', '4', '2'), vcap.get(CV_CAP_PROP_FPS), S, true);
  
  etc.

  all have same problem.

  If I set

  outputVideo.open("TEST.avi", CV_FOURCC('i', 'Y', 'U', 'V'), vcap.get(CV_CAP_PROP_FPS), S, true);

  I have error as Opencv: FFMPEG iYUV is not supported with codec id 14

  For

  outputVideo.open("TEST.avi", CV_FOURCC('M', 'J', 'P', 'G'), vcap.get(CV_CAP_PROP_FPS), S, true);
  
  
  
  
  
  OpenCV Error: Assertion failed (img.cols == width && img.rows == height && chann
  
  els == 3) in write, file /home/Softwares/opencv/opencv/modules/videoio/src/
  
  cap_mjpeg_encoder.cpp, line 829
  
  terminate called after throwing an instance of 'cv::Exception'
  
    what():  /home/Softwares/opencv/opencv/modules/videoio/src/cap_mjpeg_enco
  
  der.cpp:829: error: (-215) img.cols == width && img.rows == height && channels =
  
  = 3 in function write

  What could be wrong ? Is that my FFMPEG has problem ?