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  • Publier sur MédiaSpip

    13 June 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

  • Taille des images et des logos définissables

    9 February 2011, by

    Dans beaucoup d’endroits du site, logos et images sont redimensionnées pour correspondre aux emplacements définis par les thèmes. L’ensemble des ces tailles pouvant changer d’un thème à un autre peuvent être définies directement dans le thème et éviter ainsi à l’utilisateur de devoir les configurer manuellement après avoir changé l’apparence de son site.
    Ces tailles d’images sont également disponibles dans la configuration spécifique de MediaSPIP Core. La taille maximale du logo du site en pixels, on permet (...)

  • Supporting all media types

    13 April 2011, by

    Unlike most software and media-sharing platforms, MediaSPIP aims to manage as many different media types as possible. The following are just a few examples from an ever-expanding list of supported formats: images: png, gif, jpg, bmp and more audio: MP3, Ogg, Wav and more video: AVI, MP4, OGV, mpg, mov, wmv and more text, code and other data: OpenOffice, Microsoft Office (Word, PowerPoint, Excel), web (html, CSS), LaTeX, Google Earth and (...)

On other websites (4539)

  • Playback issues in VLC with low fps video from images using ffmpeg

    23 January 2017, by user2861936

    I am creating a short video from a sequence of 100 images using ffmpeg. There are several articles that helped me put together a command, but the one I’m using is directly taken from ffmpeg images-to-video script anyone?.

    The following command produces a video file that plays well in all video players I have (OS X).

    cat input/*.jpg | ffmpeg -f image2pipe -r 10 -vcodec mjpeg -i - out.mp4

    But if I change it to,

    cat input/*.jpg | ffmpeg -f image2pipe -r 1 -vcodec mjpeg -i - out.mp4

    It plays well in all but VLC media player. VLC displays the initial 1 to 3 images, then just freezes on the frame. I’ve tested a few different frame rates, and it seems the cutoff that breaks the video playback in VLC lies somewhere between 1.125 and 1.175.

    Any advice on what I’m dealing with here would be much appreciated.

  • ffmpeg 1.0.7 takes minute to create a thumbnail on "broken" video file but other files are seconds to create thumbnail

    8 July 2015, by Wiggler Jtag

    I’ve been using ffmpeg 1.0.7 for over 450GB (cca 400 files) for creating thumbnails and grabbing video-file information. It tooks me like 1-2 seconds to create 10 thumbnails from 8GB file. But now I’ve got some ’broken’ video file (672 MB) which creates me 1 thumbnail over a minute, 10 thumbnails its over 10 minutes -> my server burns:

     PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
    
 9769 www-data  20   0  395m  28m 7212 R 157.0  0.4   0:04.99 ffmpeg

    I opened the file in Windows Media Player and getting blank screen while -> video file is weird, opened it in VLC and it wrote me: Because this AVI file index is broken or missing, seeking will not work correctly. VLC won't repair your file but can temporary fix this problem by building an index in memory. I’ve clicked ’Play as is’ and it plays the video file correctly, however my webserver burns because of FFmpeg and PHP waits for the return from exec(); command. Thumbnails are also created fine after 10 minutes, but how can I fix this problem or to prevent from executing FFmpeg for creating thumbnails on these broken ’video’ files?

    This is my php:

    $cmd = "ffmpeg -i error.avi 2>&1";
    
$info = `$cmd`;
    
echo '<pre>';
    
print_r($info);
    
echo '</pre>';

    this is the output I am getting (very quickly)

    ffmpeg version 1.0.7 Copyright (c) 2000-2013 the FFmpeg developers
    
  built on Jul 19 2013 07:14:44 with gcc 4.7 (Debian 4.7.2-5)
    
  configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libfdk-aac --enable-libdc1394 --disable-altivec --dis  libavutil      51. 73.101 / 51. 73.101
    
  libavcodec     54. 59.100 / 54. 59.100
    
  libavformat    54. 29.104 / 54. 29.104
    
  libavdevice    54.  2.101 / 54.  2.101
    
  libavfilter     3. 17.100 /  3. 17.100
    
  libswscale      2.  1.101 /  2.  1.101
    
  libswresample   0. 15.100 /  0. 15.100
    
  libpostproc    52.  0.100 / 52.  0.100
    
Input #0, avi, from 'error.avi':
    
  Metadata:
    
    encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
    
  Duration: 01:29:39.32, start: 0.000000, bitrate: 1048 kb/s
    
    Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 640x272 [SAR 1:1 DAR 40:17], 23.98 tbr, 23.98 tbn, 23.98 tbc
    
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16, 128 kb/s
    
At least one output file must be specified

    So it looks like just creating thumbnails is having problems:

    exec("ffmpeg -ss 01:11:43 -i error.avi -vframes 1 -s 616x320 -an output_1.jpg 2>&amp;1");

    Where could be the problem? Thanks for your suggestions!

    Btw. I am posting this on SO because I’m not sure where it belongs more than here - I think it could be done somehow by PHP but I’m not really sure.

    EDIT: I have added timeout, which "fixes" my problem, but even latest version of FFmpeg 2. stucks on creating thumbnail from broken video files.

    exec("timeout 5s ffmpeg -ss 01:11:43 -i error.avi -vframes 1 -s 616x320 -an output_1.jpg 2>&amp;1");

  • trying to make OpenCV 3.2.0 work with virtualenv

    24 July 2017, by lollercoaster

    I’m on Ubuntu 16.04 with Python 2.7 and virtualenv & virtualenvwrapper.

    By following this guide I managed to get the following script working with my system Python2.7 which has cv2 globally installed.

    I used this script to install it:

    ######################################
    
# INSTALL OPENCV ON UBUNTU OR DEBIAN #
    
######################################
    

    
# |         THIS SCRIPT IS TESTED CORRECTLY ON         |
    
# |----------------------------------------------------|
    
# | OS             | OpenCV       | Test | Last test   |
    
# |----------------|--------------|------|-------------|
    
# | Ubuntu 16.04.2 | OpenCV 3.2.0 | OK   | 20 May 2017 |
    
# | Debian 8.8     | OpenCV 3.2.0 | OK   | 20 May 2017 |
    
# | Debian 9.0     | OpenCV 3.2.0 | OK   | 25 Jun 2017 |
    

    
# 1. KEEP UBUNTU OR DEBIAN UP TO DATE
    

    
sudo apt-get -y update
    
sudo apt-get -y upgrade
    
sudo apt-get -y dist-upgrade
    
sudo apt-get -y autoremove
    

    

    
# 2. INSTALL THE DEPENDENCIES
    

    
# Build tools:
    
sudo apt-get install -y build-essential cmake
    

    
# GUI (if you want to use GTK instead of Qt, replace 'qt5-default' with 'libgtkglext1-dev' and remove '-DWITH_QT=ON' option in CMake):
    
sudo apt-get install -y qt5-default libvtk6-dev
    

    
# Media I/O:
    
sudo apt-get install -y zlib1g-dev libjpeg-dev libwebp-dev libpng-dev libtiff5-dev libjasper-dev libopenexr-dev libgdal-dev
    

    
# Video I/O:
    
sudo apt-get install -y libdc1394-22-dev libavcodec-dev libavformat-dev libswscale-dev libtheora-dev libvorbis-dev libxvidcore-dev libx264-dev yasm libopencore-amrnb-dev libopencore-amrwb-dev libv4l-dev libxine2-dev
    

    
# Parallelism and linear algebra libraries:
    
sudo apt-get install -y libtbb-dev libeigen3-dev
    

    
# Python:
    
sudo apt-get install -y python-dev python-tk python-numpy python3-dev python3-tk python3-numpy
    

    
# Documentation:
    
sudo apt-get install -y doxygen
    

    
# UI stuff
    
sudo apt-get install libgtk-3-dev libatlas-base-dev gfortran
    

    

    
# 3. INSTALL THE LIBRARY (YOU CAN CHANGE '3.2.0' FOR THE LAST STABLE VERSION)
    
sudo apt-get install -y unzip wget
    

    
# opencv contrib
    
wget https://github.com/opencv/opencv_contrib/archive/3.2.0.zip -O opencv_contrib-3.2.0.zip
    
unzip opencv_contrib-3.2.0.zip
    
rm opencv_contrib-3.2.0.zip
    

    
# opencv
    
wget https://github.com/opencv/opencv/archive/3.2.0.zip
    
unzip 3.2.0.zip
    
rm 3.2.0.zip
    
mv opencv-3.2.0 OpenCV-3.2.0
    
cd OpenCV-3.2.0
    

    
mkdir build
    
cd build
    
cmake -D WITH_QT=ON \
    
    -D WITH_OPENGL=ON \
    
    -D FORCE_VTK=ON \
    
    -D WITH_TBB=ON \
    
    -D WITH_GDAL=ON \
    
    -D WITH_XINE=ON \
    
    -D BUILD_EXAMPLES=ON \
    
    -D INSTALL_PYTHON_EXAMPLES=ON \
    
    -D ENABLE_PRECOMPILED_HEADERS=OFF \
    
    -D BUILD_NEW_PYTHON_SUPPORT=ON \
    
    ..
    

    
make -j4
    
sudo make install
    
sudo ldconfig
    

    

    
# 4. EXECUTE SOME OPENCV EXAMPLES AND COMPILE A DEMONSTRATION
    

    
# To complete this step, please visit 'http://milq.github.io/install-opencv-ubuntu-debian'.

    The following script below works great with that system-wide installation:

    import cv2
    

    
img = cv2.imread('some_img.jpg')

    Though this one doesn’t - even the system Python can’t read videos for some reason...

    import cv2
    

    
video_capture = cv2.VideoCapture(0)
    
ret, frame = video_capture.read()
    
print ret  # always False

    but I want it to work with my virtualenv. So I recompiled OpenCV with:

    cmake -D WITH_QT=ON \
    
    -D WITH_OPENGL=ON \
    
    -D FORCE_VTK=ON \
    
    -D WITH_TBB=ON \
    
    -D WITH_GDAL=ON \
    
    -D WITH_XINE=ON \
    
    -D BUILD_EXAMPLES=ON \
    
    -D INSTALL_PYTHON_EXAMPLES=ON \
    
    -D ENABLE_PRECOMPILED_HEADERS=OFF \
    
    -D BUILD_NEW_PYTHON_SUPPORT=ON \
    
    -D OPENCV_EXTRA_MODULES_PATH=/home/me/code/myproject/opencv_contrib-3.2.0/modules \
    
    -D PYTHON_EXECUTABLE=~/.envs/myenv/bin/python \
    
    ..
    

    
make -j4
    
sudo make install
    
sudo ldconfig

    Here’s the CMake log:

    -- Found VTK ver. 6.2.0 (usefile: /usr/lib/cmake/vtk-6.2/UseVTK.cmake)
    
-- Caffe:   NO
    
-- Protobuf:   YES
    
-- Glog:   NO
    
-- freetype2:   YES
    
-- harfbuzz:    YES
    
-- Module opencv_sfm disabled because the following dependencies are not found: Glog/Gflags
    
-- freetype2:   YES
    
-- harfbuzz:    YES
    
-- Checking for modules 'tesseract;lept'
    
--   No package 'tesseract' found
    
--   No package 'lept' found
    
-- Tesseract:   NO
    
-- Check contents of vgg_generated_48.i ...
    
-- Check contents of vgg_generated_64.i ...
    
-- Check contents of vgg_generated_80.i ...
    
-- Check contents of vgg_generated_120.i ...
    
-- Check contents of boostdesc_bgm.i ...
    
-- Check contents of boostdesc_bgm_bi.i ...
    
-- Check contents of boostdesc_bgm_hd.i ...
    
-- Check contents of boostdesc_binboost_064.i ...
    
-- Check contents of boostdesc_binboost_128.i ...
    
-- Check contents of boostdesc_binboost_256.i ...
    
-- Check contents of boostdesc_lbgm.i ...
    
-- 
    
-- General configuration for OpenCV 3.2.0 =====================================
    
--   Version control:               817bd7b-dirty
    
-- 
    
--   Extra modules:
    
--     Location (extra):            /home/me/code/myproject/opencv_contrib-3.2.0/modules
    
--     Version control (extra):     817bd7b-dirty
    
-- 
    
--   Platform:
    
--     Timestamp:                   2017-07-20T18:25:26Z
    
--     Host:                        Linux 4.8.0-58-generic x86_64
    
--     CMake:                       3.5.1
    
--     CMake generator:             Unix Makefiles
    
--     CMake build tool:            /usr/bin/make
    
--     Configuration:               Release
    
-- 
    
--   C/C++:
    
--     Built as dynamic libs?:      YES
    
--     C++ Compiler:                /usr/bin/c++  (ver 5.4.0)
    
--     C++ flags (Release):         -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG  -DNDEBUG
    
--     C++ flags (Debug):           -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG
    
--     C Compiler:                  /usr/bin/cc
    
--     C flags (Release):           -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -O3 -DNDEBUG  -DNDEBUG
    
--     C flags (Debug):             -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -msse -msse2 -mno-avx -msse3 -mno-ssse3 -mno-sse4.1 -mno-sse4.2 -ffunction-sections -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG
    
--     Linker flags (Release):
    
--     Linker flags (Debug):
    
--     ccache:                      NO
    
--     Precompiled headers:         NO
    
--     Extra dependencies:          Qt5::Test Qt5::Concurrent Qt5::OpenGL /usr/lib/x86_64-linux-gnu/libwebp.so /usr/lib/x86_64-linux-gnu/libjasper.so /usr/lib/x86_64-linux-gnu/libImath.so /usr/lib/x86_64-linux-gnu/libIlmImf.so /usr/lib/x86_64-linux-gnu/libIex.so /usr/lib/x86_64-linux-gnu/libHalf.so /usr/lib/x86_64-linux-gnu/libIlmThread.so /usr/lib/libgdal.so dc1394 xine avcodec-ffmpeg avformat-ffmpeg avutil-ffmpeg swscale-ffmpeg Qt5::Core Qt5::Gui Qt5::Widgets /usr/lib/x86_64-linux-gnu/hdf5/serial/lib/libhdf5.so /usr/lib/x86_64-linux-gnu/libpthread.so /usr/lib/x86_64-linux-gnu/libsz.so /usr/lib/x86_64-linux-gnu/libdl.so /usr/lib/x86_64-linux-gnu/libm.so vtkRenderingOpenGL vtkImagingHybrid vtkIOImage vtkCommonDataModel vtkCommonMath vtkCommonCore vtksys vtkCommonMisc vtkCommonSystem vtkCommonTransforms vtkCommonExecutionModel vtkDICOMParser vtkIOCore /usr/lib/x86_64-linux-gnu/libz.so vtkmetaio /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib/x86_64-linux-gnu/libpng.so /usr/lib/x86_64-linux-gnu/libtiff.so vtkImagingCore vtkRenderingCore vtkCommonColor vtkFiltersExtraction vtkFiltersCore vtkFiltersGeneral vtkCommonComputationalGeometry vtkFiltersStatistics vtkImagingFourier vtkalglib vtkFiltersGeometry vtkFiltersSources vtkInteractionStyle vtkRenderingLOD vtkFiltersModeling vtkIOPLY vtkIOGeometry /usr/lib/x86_64-linux-gnu/libjsoncpp.so vtkFiltersTexture vtkRenderingFreeType /usr/lib/x86_64-linux-gnu/libfreetype.so vtkftgl vtkIOExport vtkRenderingAnnotation vtkImagingColor vtkRenderingContext2D vtkRenderingGL2PS vtkRenderingContextOpenGL /usr/lib/libgl2ps.so vtkRenderingLabel dl m pthread rt /usr/lib/x86_64-linux-gnu/libGLU.so /usr/lib/x86_64-linux-gnu/libGL.so tbb
    
--     3rdparty dependencies:       libprotobuf
    
-- 
    
--   OpenCV modules:
    
--     To be built:                 core flann hdf imgproc ml photo reg surface_matching video viz dnn freetype fuzzy imgcodecs shape videoio highgui objdetect plot superres ts xobjdetect xphoto bgsegm bioinspired dpm face features2d line_descriptor saliency text calib3d ccalib cvv datasets rgbd stereo tracking videostab xfeatures2d ximgproc aruco optflow phase_unwrapping stitching structured_light java python2 python3
    
--     Disabled:                    world contrib_world
    
--     Disabled by dependency:      -
    
--     Unavailable:                 cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev cnn_3dobj matlab sfm
    
-- 
    
--   GUI: 
    
--     QT 5.x:                      YES (ver 5.5.1)
    
--     QT OpenGL support:           YES (Qt5::OpenGL 5.5.1)
    
--     OpenGL support:              YES (/usr/lib/x86_64-linux-gnu/libGLU.so /usr/lib/x86_64-linux-gnu/libGL.so)
    
--     VTK support:                 YES (ver 6.2.0)
    
-- 
    
--   Media I/O: 
    
--     ZLib:                        /usr/lib/x86_64-linux-gnu/libz.so (ver 1.2.8)
    
--     JPEG:                        /usr/lib/x86_64-linux-gnu/libjpeg.so (ver )
    
--     WEBP:                        /usr/lib/x86_64-linux-gnu/libwebp.so (ver encoder: 0x0202)
    
--     PNG:                         /usr/lib/x86_64-linux-gnu/libpng.so (ver 1.2.54)
    
--     TIFF:                        /usr/lib/x86_64-linux-gnu/libtiff.so (ver 42 - 4.0.6)
    
--     JPEG 2000:                   /usr/lib/x86_64-linux-gnu/libjasper.so (ver 1.900.1)
    
--     OpenEXR:                     /usr/lib/x86_64-linux-gnu/libImath.so /usr/lib/x86_64-linux-gnu/libIlmImf.so /usr/lib/x86_64-linux-gnu/libIex.so /usr/lib/x86_64-linux-gnu/libHalf.so /usr/lib/x86_64-linux-gnu/libIlmThread.so (ver 2.2.0)
    
--     GDAL:                        /usr/lib/libgdal.so
    
--     GDCM:                        NO
    
-- 
    
--   Video I/O:
    
--     DC1394 1.x:                  NO
    
--     DC1394 2.x:                  YES (ver 2.2.4)
    
--     FFMPEG:                      YES
    
--       avcodec:                   YES (ver 56.60.100)
    
--       avformat:                  YES (ver 56.40.101)
    
--       avutil:                    YES (ver 54.31.100)
    
--       swscale:                   YES (ver 3.1.101)
    
--       avresample:                NO
    
--     GStreamer:                   NO
    
--     OpenNI:                      NO
    
--     OpenNI PrimeSensor Modules:  NO
    
--     OpenNI2:                     NO
    
--     PvAPI:                       NO
    
--     GigEVisionSDK:               NO
    
--     Aravis SDK:                  NO
    
--     UniCap:                      NO
    
--     UniCap ucil:                 NO
    
--     V4L/V4L2:                    NO/YES
    
--     XIMEA:                       NO
    
--     Xine:                        YES (ver 1.2.6)
    
--     gPhoto2:                     NO
    
-- 
    
--   Parallel framework:            TBB (ver 4.4 interface 9002)
    
-- 
    
--   Other third-party libraries:
    
--     Use IPP:                     9.0.1 [9.0.1]
    
--          at:                     /home/me/code/myproject/OpenCV-3.2.0/build/3rdparty/ippicv/ippicv_lnx
    
--     Use IPP Async:               NO
    
--     Use VA:                      NO
    
--     Use Intel VA-API/OpenCL:     NO
    
--     Use Lapack:                  NO
    
--     Use Eigen:                   YES (ver 3.2.92)
    
--     Use Cuda:                    NO
    
--     Use OpenCL:                  YES
    
--     Use OpenVX:                  NO
    
--     Use custom HAL:              NO
    
-- 
    
--   OpenCL:                        <dynamic loading="loading" of="of" opencl="opencl" library="library">
    
--     Include path:                /home/me/code/myproject/OpenCV-3.2.0/3rdparty/include/opencl/1.2
    
--     Use AMDFFT:                  NO
    
--     Use AMDBLAS:                 NO
    
-- 
    
--   Python 2:
    
--     Interpreter:                 /home/me/.envs/myenv/bin/python (ver 2.7.12)
    
--     Libraries:                   /usr/lib/x86_64-linux-gnu/libpython2.7.so (ver 2.7.12)
    
--     numpy:                       /home/me/.envs/myenv/local/lib/python2.7/site-packages/numpy/core/include (ver 1.13.1)
    
--     packages path:               lib/python2.7/site-packages
    
-- 
    
--   Python 3:
    
--     Interpreter:                 /usr/bin/python3 (ver 3.5.2)
    
--     Libraries:                   /usr/lib/x86_64-linux-gnu/libpython3.5m.so (ver 3.5.2)
    
--     numpy:                       /usr/lib/python3/dist-packages/numpy/core/include (ver 1.11.0)
    
--     packages path:               lib/python3.5/dist-packages
    
-- 
    
--   Python (for build):            /home/me/.envs/myenv/bin/python
    
-- 
    
--   Java:
    
--     ant:                         /usr/bin/ant (ver 1.9.6)
    
--     JNI:                         /usr/lib/jvm/default-java/include /usr/lib/jvm/default-java/include/linux /usr/lib/jvm/default-java/include
    
--     Java wrappers:               YES
    
--     Java tests:                  YES
    
-- 
    
--   Matlab:                        Matlab not found or implicitly disabled
    
-- 
    
--   Documentation:
    
--     Doxygen:                     /usr/bin/doxygen (ver 1.8.11)
    
-- 
    
--   Tests and samples:
    
--     Tests:                       YES
    
--     Performance tests:           YES
    
--     C/C++ Examples:              YES
    
-- 
    
--   Install path:                  /usr/local
    
-- 
    
--   cvconfig.h is in:              /home/me/code/myproject/OpenCV-3.2.0/build
    
-- -----------------------------------------------------------------
    
-- 
    
</dynamic>

    Unfortunately, while this works and I can import cv2 in the shell, it cannot read video using the above script, probably due to incorrect compilation or linking of ffmpeg? The confusing part is the system-wide installation of OpenCV works fine, even without ffmpeg installed!

    What am I doing wrong? How can I get OpenCV working with a virtualenv?

    ====

    EDIT: Running the C++ video writing example has this result:

    $ cd /home/me/code/myproject/OpenCV-3.2.0/build/bin
    
$ ./cpp-tutorial-video-write ../../samples/data/vtest.avi R Y
    
------------------------------------------------------------------------------
    
This program shows how to write video files.
    
You can extract the R or G or B color channel of the input video.
    
Usage:
    
./video-write  [ R | G | B] [Y | N]
    
------------------------------------------------------------------------------
    

    
OpenCV: FFMPEG: tag 0xffffffff/'����' is not found (format 'avi / AVI (Audio Video Interleaved)')'
    

    
(cpp-tutorial-video-write:19523): GStreamer-CRITICAL **: gst_element_make_from_uri: assertion 'gst_uri_is_valid (uri)' failed
    
OpenCV Error: Unsupported format or combination of formats (Gstreamer Opencv backend does not support this codec.) in CvVideoWriter_GStreamer::open, file /home/me/code/myproject/OpenCV-3.2.0/modules/videoio/src/cap_gstreamer.cpp, line 1388
    
VIDEOIO(cvCreateVideoWriter_GStreamer(filename, fourcc, fps, frameSize, is_color)): raised OpenCV exception:
    

    
/home/me/code/myproject/OpenCV-3.2.0/modules/videoio/src/cap_gstreamer.cpp:1388: error: (-210) Gstreamer Opencv backend does not support this codec. in function CvVideoWriter_GStreamer::open
    

    
Could not open the output video for write: ../../samples/data/vtest.avi

    And the opencv_test_videoio unit test reports the following: https://pastebin.com/q4mf224Q

    However, running the c++ video starter example DOES work, with the following command and output, I can see the webcam working and streaming video in the highgui interface:

    $ ./cpp-example-videocapture_starter 0
    
VIDEOIO ERROR: V4L: device 0: Unable to query number of channels
    
(ERROR)icvOpenAVI_XINE(): Unable to initialize video driver.
    
GStreamer: Error opening bin: no element "0"
    
press space to save a picture. q or esc to quit
    
init done
    
opengl support available

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