Recherche avancée

Sur d’autres sites (9037)

• OpenCV can't find ffmpeg (?)

  28 avril 2019, par spacetimedivider

  I can’t get OpenCV to use FFMpeg for capturing webcam or video playback. (Windows, C++)

  I downloaded latest OpenCV 4.1 and set it up in Visual Studio. It basically compiles and runs.

  As far as I can see, the OpenCV I downloaded is build with FFMpeg (?).

  I just want to capture my webcam :

  VideoCapture capture;
  
  
  
  capture.open(0);
  
  if (!capture.isOpened()) return;
  
  
  
  Mat frame;
  
  while (capture.read(frame))
  
  {
  
      if (frame.empty()) {
  
          cout << "frame empty" << endl;
  
      }
  
      imshow("capture", frame);
  
  }
  
  capture.release();
  
  destroyAllWindows();
  
  return 0;

  the result I get is :

  [ INFO:0] VIDEOIO: Enabled backends(6, sorted by priority): FFMPEG(1000); GSTREAMER(990); MSMF(980); DSHOW(970); CV_IMAGES(960); CV_MJPEG(950)
  
  [ INFO:0] VideoIO pluigin (GSTREAMER): glob is 'opencv_videoio_gstreamer*.dll', 1 location(s)
  
  [ INFO:0]     - C:\opencv4.1\build\x64\vc15\bin: 0
  
  [ INFO:0] Found 0 plugin(s) for GSTREAMER

  (I don’t want to use GStreamer, I want ffmpeg)

  I tried to force OpenCV to use ffmpeg with

  capture.open(0 + cv::CAP_FFMPEG);

  but then it can’t open the camera device.

  What do I have to do that OpenCV finds ffmpeg ?

• mediaReader.readPacket() blocks while trying to read rtsp stream in Xuggler

  29 novembre 2015, par user3601262

  I am trying to download a video (with a Xuggler 5.4 library) from rtsp stream to a file using the code below.

      String inputSource = "rtsp://[ip-address]:[port]/user=[username]&[password]=password&channel=1&stream=1.sdp";
  
      String outputFilename = "d:/downloadedrtsp.flv";
  
      try {
  
          IContainerFormat inFormat = IContainerFormat.make();
  
          inFormat.setInputFormat("h246");
  
  
  
          IMediaReader mediaReader = ToolFactory.makeReader(inputSource);
  
          mediaReader.setQueryMetaData(false);
  
  
  
          IMediaWriter mediaWriter = ToolFactory.makeWriter(outputFilename, mediaReader);
  
          mediaReader.addListener(mediaWriter);
  
  
  
          logger.info("before reading");
  
          IError error;
  
          while ((error = mediaReader.readPacket()) == null) {
  
              logger.info("reading packet");
  
          }
  
          logger.info("error: " + error.getDescription());
  
          logger.info(error.getType());
  
          logger.info(error.toString());
  
      } catch (Exception e) {
  
          e.printStackTrace();
  
      }

  The problem is that after printing "before reading" the code just stop executing, and after a long time it prints me three lines from logger :

  error : Unknown error

  ERROR_EOF

  Unknown error

  Stream works great when i am opening it in the VLC media player. I am shure there is some mistake in my mediaReader configuration, but i don’t know where exactly as i have a very little experience working with videos. Here is some information about video, taken from VLC :

  

• Evolution #3482 : Sanitizer les SVG

  31 juillet 2017

  Un article pour compléter https://korben.info/uploader-fichier-svg-wordpress.html
  Contient des liens vers des explications du danger.
  Et le lien vers un plugin WP qui gère(rait) la sécurité des SVG.