For more time than I am willing to admit, I have tried getting the Beaglebone Black up and running with OpenCV and a camera. However, having compiled OpenCV 4.0.0/3.4.6/3.4.0 manually and trying to initialize a camera using the Python bindings, it continue to fail.
Using v4l2-ctl I can both view and set formats etc. from the terminal, but when trying something as simple as
`
import cv2
vs = cv2.VideoCapture(0)
retVal, frame = vs.read()
`
this yields:
`
select timeout
VIDIOC_DQBUF: Resource temporarily unavailable
`
Camera works perfectly fine on a Raspberry Pi and my PC, and funny thing - on the Beaglebone I tried to install OpenCV using apt-get which made the camera work just fine.
So
sudo apt-get install python-opencv
which installs OpenCV 3.2.0 (without any hardware optimizations for arm) works…
Would any of you happen to know what I am missing here? Is there simply a bug in OpenCV or am I missing something for my build?
For more information I have attached my build overview below:
`
cmake -D CMAKE_BUILD_TYPE=RELEASE
-D CMAKE_INSTALL_PREFIX=/usr/local
-D ENABLE_NEON=ON
-D ENABLE_VFPV3=ON
-D BUILD_TESTS=OFF
-D INSTALL_PYTHON_EXAMPLES=OFF
-D BUILD_EXAMPLES=OFF
-D WITH_JPEG=ON
-D BUILD_JPEG=OFF
-D JPEG_INCLUDE_DIR=/opt/libjpeg-turbo/include/
-D JPEG_LIBRARY=/opt/libjpeg-turbo/lib32/libjpeg.a
-D WITH_V4L=ON …
– Looking for ccache - not found
– FP16 is not supported by C++ compiler
– Found ZLIB: /usr/lib/arm-linux-gnueabihf/libz.so (found suitable version “1.2.8”, minimum required is “1.2.3”)
– Could NOT find Jasper (missing: JASPER_LIBRARIES JASPER_INCLUDE_DIR)
– Found ZLIB: /usr/lib/arm-linux-gnueabihf/libz.so (found version “1.2.8”)
– Checking for module ‘gstreamer-base-1.0’
– No package ‘gstreamer-base-1.0’ found
– Checking for module ‘gstreamer-video-1.0’
– No package ‘gstreamer-video-1.0’ found
– Checking for module ‘gstreamer-app-1.0’
– No package ‘gstreamer-app-1.0’ found
– Checking for module ‘gstreamer-riff-1.0’
– No package ‘gstreamer-riff-1.0’ found
– Checking for module ‘gstreamer-pbutils-1.0’
– No package ‘gstreamer-pbutils-1.0’ found
– Checking for module ‘gstreamer-base-0.10’
– No package ‘gstreamer-base-0.10’ found
– Checking for module ‘gstreamer-video-0.10’
– No package ‘gstreamer-video-0.10’ found
– Checking for module ‘gstreamer-app-0.10’
– No package ‘gstreamer-app-0.10’ found
– Checking for module ‘gstreamer-riff-0.10’
– No package ‘gstreamer-riff-0.10’ found
– Checking for module ‘gstreamer-pbutils-0.10’
– No package ‘gstreamer-pbutils-0.10’ found
– Checking for module ‘libdc1394-2’
– No package ‘libdc1394-2’ found
– Checking for module ‘libdc1394’
– No package ‘libdc1394’ found
– Looking for linux/videodev2.h
– Looking for linux/videodev2.h - found
– Looking for sys/videoio.h
– Looking for sys/videoio.h - not found
– Checking for module ‘libavresample’
– No package ‘libavresample’ found
– Could not find OpenBLAS lib. Turning OpenBLAS_FOUND off
– Could NOT find Atlas (missing: Atlas_CLAPACK_INCLUDE_DIR)
– A library with BLAS API found.
– A library with LAPACK API found.
– Could NOT find JNI (missing: JAVA_AWT_LIBRARY JAVA_JVM_LIBRARY JAVA_INCLUDE_PATH JAVA_INCLUDE_PATH2 JAVA_AWT_INCLUDE_PATH)
– VTK is not found. Please set -DVTK_DIR in CMake to VTK build directory, or to VTK install subdirectory with VTKConfig.cmake file
– OpenCV Python: during development append to PYTHONPATH: /mnt/ext2/opencv-4.0.0/build/python_loader
– Excluding from source files list: modules/imgproc/src/corner.avx.cpp
– Excluding from source files list: modules/imgproc/src/filter.avx2.cpp
– Excluding from source files list: modules/imgproc/src/imgwarp.avx2.cpp
– Excluding from source files list: modules/imgproc/src/imgwarp.sse4_1.cpp
– Excluding from source files list: modules/imgproc/src/resize.avx2.cpp
– Excluding from source files list: modules/imgproc/src/resize.sse4_1.cpp
– Excluding from source files list: /modules/dnn/layers/layers_common.avx.cpp
– Excluding from source files list: /modules/dnn/layers/layers_common.avx2.cpp
– Excluding from source files list: /modules/dnn/layers/layers_common.avx512_skx.cpp
– Excluding from source files list: modules/features2d/src/fast.avx2.cpp
– Excluding from source files list: modules/calib3d/src/undistort.avx2.cpp