Recherche avancée

Sur d’autres sites (9723)

• VideoCapture is not working in OpenCV 2.4.2

  31 mai 2016, par Froyo

  I recently installed OpenCV 2.4.2 in Ubuntu 12.04.

  cap = VideoCapture(0)

  is working. but I can’t grab frames from some video source.

  cap = VideoCapture("input.avi")
  
  img = cap.read() 

  gives me a numpy with all zero elements.

  I have also installed ffmpeg 0.11, Latest snapshot of x264, v4l-0.8.8 (All are latest stable versions)

  cmake -D WITH_QT=ON -D WITH_FFMPEG=ON -D WITH_OPENGL=ON -D WITH_TBB=ON -D BUILD_EXAMPLES=OFF WITH_V4L=ON .. 
  
  make
  
  sudo make install

  When I do cmake, I get this

  — Detected version of GNU GCC : 46 (406)
  — Found OpenEXR : /usr/lib/libIlmImf.so
  — Looking for linux/videodev.h
  — Looking for linux/videodev.h - not found
  — Looking for linux/videodev2.h
  — Looking for linux/videodev2.h - found
  — Looking for libavformat/avformat.h
  — Looking for libavformat/avformat.h - found
  — Looking for ffmpeg/avformat.h
  — Looking for ffmpeg/avformat.h - not found
  — checking for module ’tbb’
  — package ’tbb’ not found

  And

  --   Video I/O:  
  
  --     DC1394 1.x:                  NO  
  
  --     DC1394 2.x:                  YES (ver 2.2.0)  
  
  --     FFMPEG:                      YES  
  
  --       codec:                     YES (ver 54.23.100)  
  
  --       format:                    YES (ver 54.6.100)  
  
  --       util:                      YES (ver 51.54.100)  
  
  --       swscale:                   YES (ver 2.1.100)  
  
  --       gentoo-style:              YES  
  
  --     GStreamer:                   
  
  --       base:                      YES (ver 0.10.36)  
  
  --       app:                       YES (ver 0.10.36)  
  
  --       video:                     YES (ver 0.10.36)  
  
  --     OpenNI:                      NO  
  
  --     OpenNI PrimeSensor Modules:  NO  
  
  --     PvAPI:                       NO  
  
  --     UniCap:                      NO  
  
  --     UniCap ucil:                 NO  
  
  --     V4L/V4L2:                    Using libv4l (ver 0.8.8)  
  
  --     XIMEA:                       NO  
  
  --     Xine:                        NO

  I looked for videodev.h, etc

  • /usr/include/linux/videodev2.h exists
  • /usr/include/libavformat/avformat.h exists
  • /usr/local/include/libavformat/avformat.h exists

  But I couldn’t find ffmpeg/avformat.h

  What’s the problem here ?

• ffmpeg won't ./configure in iOS5.1

  17 juillet 2015, par Chuck Mc Duran

  I am trying to build ffmpeg on iOS5.1 (armv7), when I try to run ./configure like this :

  ./configure --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffserver
  
     --enable-cross-compile --arch=arm --target-os=darwin
  
     --cc=/applications/xcode.app/contents/Developer/usr/bin/gcc
  
     --as='gas-preprocessor/gas-preprocessor.pl /applications/xcode.app/contents/Developer/usr/bin/gcc'
  
     --sysroot=/applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk
  
     --cpu=cortex-a8 --extra-cflags='-arch armv7'
  
     --extra-ldflags='-arch armv7 -isysroot /applications/xcode.app/contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk'
  
     --enable-pic

  I get the following error :

  /applications/xcode.app/contents/Developer/usr/bin/gcc
  
  is unable to create an executable file.
  
  C compiler test failed.

  If you think configure made a mistake, make sure you are using the latest
  version from SVN. If the latest version fails, report the problem to the
  ffmpeg-user@mplayerhq.hu mailing list or IRC #ffmpeg on irc.freenode.net.
  Include the log file "config.err" produced by configure as this will help
  solving the problem.

  Could somebody please provide the correct parameters in iOS5.1 ?

  Thanks in advance

• PHP-FFMpeg prerequisites

  20 février 2014, par Jesse Adam

  
  I'm attempting to implement https://github.com/PHP-FFMpeg/PHP-FFMpeg

  I copied the src/FFMpeg folder to my includes folder and made sure my autoloader knows where to find everything.

  as a test I made a script that simply does :

  $ffmpeg = FFMpeg\FFMpeg::create();
  
  $video = $ffmpeg->open('video.mpg');

  I get :

  Fatal error: Class 'Doctrine\Common\Cache\ArrayCache' not found in /var/www/php/include/FFMpeg/FFProbe.php on line 203 

  My question is : does PHP-FFMPeg require Doctrine, because that is not stated in the documentation. What version do I need ? Are there other prerequisites ?

  I could create a new question for this, but I'm not sure if I should. I now have PHP-ffmpeg implemented. I'm using Laravel, however that should be irrelevant for this question. I'm trying to enable progress monitoring. It works, however I need to pass in an ID so I can update the correct key in memcache.

  $id = 12345;
  
  $format->on('progress', function ($audio, $format, $percentage) {
  
      //this works perfect, but doesn't tell me which item is being updated 
  
      Cache::put("progress", $percentage,  .25);
  
  
  
      //this does not work as I am unable to pass in $id, if I add it as the 4th argument above it will display the number of threads or something
  
      //Cache::put("{$id}_progress", $percentage,  .25);          
  
  });

  I need clarification on the "on" method. I looked through https://ffmpeg-php.readthedocs.org/en/latest/_static/API/ and was not able to figure out how this method works. Any help would be appreciated.