Cross compile opencv project on Ubuntu for Raspberry Pi

Question

I'm struggling with this for 2 days now and don't get it to work.

What I've done so far:

• built opencv 2.4.8 from source on Ubuntu 12.04 LTS --> OpenCV projects compile and run on ubuntu

• built opencv 2.4.8 from source on the Raspberry Pi Raspian --> OpenCV projects compile and run on the Raspberry Pi

• built a cross compiler for the Raspberry Pi with crosstools-ng ( http://www.bootc.net/archives/2012/05/26/how-to-build-a-cross-compiler-for-your-raspberry-pi/ ) --> c++ programs built on Ubuntu with the crosscompiler run on the Raspberry Pi

---

What are my problems:

OpenCV programs don't compile with the cross compiler

|2|fatal error: opencv2/highgui/highgui.hpp: No such file or directory|

I think I need to cross compile OpenCV as well on ubuntu. From my cross compiler I also have a toolchain

# this one is important
SET(CMAKE_SYSTEM_NAME Linux)
#this one not so much
SET(CMAKE_SYSTEM_VERSION 1)

# specify the cross compiler
SET(CMAKE_C_COMPILER
/home/christian/Programming/x-tools/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc)

SET(CMAKE_CXX_COMPILER
/home/christian/Programming/x-tools/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-g++)

# where is the target environment
SET(CMAKE_FIND_ROOT_PATH
/home/christian/Programming/x-tools/arm-unknown-linux-gnueabi)

# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

with this toolchain I tried to cross compile OpenCV with this command:

cmake -DCMAKE_TOOLCHAIN_FILE=../Toolchain-RaspberryPi.cmake ../

After the make command it compiles until 27%. There it stops with this error

[ 27%] Building CXX object modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o
In file included from /home/christian/Downloads/opencv-2.4.8/modules/highgui/src/cap_ffmpeg_impl.hpp:60:0,
                 from /home/christian/Downloads/opencv-2.4.8/modules/highgui/src/cap_ffmpeg.cpp:45:
/home/christian/Downloads/opencv-2.4.8/modules/highgui/src/ffmpeg_codecs.hpp:81:36: fatal error: libavformat/avformat.h: No such file or directory
   #include <libavformat/avformat.h>
                                    ^
compilation terminated.
make[2]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o] Error 1
make[1]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/all] Error 2
make: *** [all] Error 2

I tried to copy the OpenCV headers and libs compiled on the Raspberry Pi to my ubuntu computer and link them. I get loads of errors while compiling

||=== RPi_Cross_CV, Debug ===|
||warning: libz.so.1, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_core.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libjpeg.so.8, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libpng12.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libtiff.so.4, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libjasper.so.1, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgtk-x11-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgdk-x11-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libatk-1.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgio-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libpangoft2-1.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libpangocairo-1.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgdk_pixbuf-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libcairo.so.2, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libpango-1.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libfreetype.so.6, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libfontconfig.so.1, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgobject-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libglib-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgthread-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgstbase-0.10.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgstreamer-0.10.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libgmodule-2.0.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libxml2.so.2, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libdc1394.so.22, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libv4l1.so.0, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libavcodec.so.53, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libavformat.so.53, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libavutil.so.51, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
||warning: libswscale.so.2, needed by ../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8, not found (try using -rpath or -rpath-link)|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `TIFFSetWarningHandler@LIBTIFF_3.9'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `png_read_info@PNG12_0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_time_val_add'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jas_image_writecmpt'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_widget_queue_draw'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `av_guess_codec@LIBAVFORMAT_53'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `av_rescale_q@LIBAVUTIL_51'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jpeg_std_error@LIBJPEG_8.0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jas_cmprof_destroy'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `png_get_tRNS@PNG12_0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_return_if_fail_warning'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_camera_enumerate'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_capture_stop'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `compress'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_get_image_size_from_video_mode'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_timeout_add'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `png_set_packing@PNG12_0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `v4l2_munmap'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_feature_whitebalance_get_value'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_type_new'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jas_image_destroy'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `avcodec_close@LIBAVCODEC_53'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `sws_getCachedContext@LIBSWSCALE_2'|
../../../../Programming/x-tools/usr-local/lib/libopencv_core.so.2.4.8||undefined reference to `gzeof'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_style_attach'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_widget_get_type'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_window_resize'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_cond_broadcast'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_video_get_supported_framerates'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jpeg_read_header@LIBJPEG_8.0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `avio_open@LIBAVFORMAT_53'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `TIFFReadEncodedTile@LIBTIFF_3.9'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `uncompress'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_type_check_instance_cast'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_usleep'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `avcodec_find_decoder@LIBAVCODEC_53'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `g_get_current_time'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jpeg_set_defaults@LIBJPEG_8.0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_video_get_mode'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jpeg_start_compress@LIBJPEG_8.0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `av_free_packet@LIBAVCODEC_53'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_window_set_geometry_hints'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_signal_connect_full'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gdk_draw_rgb_image'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_widget_queue_resize'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `dc1394_video_set_mode'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jas_stream_close'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jpeg_set_quality@LIBJPEG_8.0'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `jas_image_readcmpt'|
../../../../Programming/x-tools/usr-local/lib/libopencv_highgui.so.2.4.8||undefined reference to `gtk_disable_setlocale'|
||More errors follow but not being shown.|
||Edit the max errors limit in compiler options...|
||=== Build finished: 50 errors, 29 warnings ===|

---

So my question is:

How can I get a crosscompiler on ubuntu to work with opencv? I just want to compile on ubuntu, copy the program on the Pi and run it there.

Thanks a lot

Answer 1

I realize this is an old question but for the record I was able to cross compile my OpenCV project from Ubuntu.

In my case I used the the pre-built raspberry pi toolchain on github: https://github.com/raspberrypi/tools on Ubuntu 12.0.4. I took the approach of copying the native libraries (with OpenCV and PiCamera libraries installed) from the target Raspberry Pi system to the Ubuntu instance and using the CMAKE_TOOLCHAIN_FILE support like you mention in your post.

However, there were certain issues I had to overcome, which I cover in this post: https://solderspot.wordpress.com/2016/02/04/cross-compiling-for-raspberry-pi-part-ii

The key points were:

1. CMAKE_FIND_ROOT_PATH had not effect. I had to use CMAKE_SYSROOT.

2. In my CMakeLists.txt file I still had to explicitly prepend any paths with the path to the folder where I had copied over the native file system.

3. I also needed to explicitly specify the dynamic library link paths from within CMAKE_TOOLCHAIN_FILE as the toolchain does not correctly parser the /usr/etc/ld.so.conf file.

The only current issue I could not solve yet was to do with the Jessie release of Raspbian, as OpenCV uses an gcc/g++ 4.9 feature that is not supported by the gcc/g++ 4.8 version of the toolchain. It looks like the toolchain will be augmented to support 4.9 in the near future.

My final CMAKE_TOOLCHAIN_FILE was:

SET(CMAKE_SYSTEM_NAME Linux)
SET(CMAKE_SYSTEM_VERSION 1)

SET(DEVROOT $ENV{HOME}/pidev)
SET(PIROOT ${DEVROOT}/piroot)
SET(PITOOLS ${DEVROOT}/pitools)

SET(TOOLROOT ${PITOOLS}/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64)

# specify the cross compiler
SET(CMAKE_C_COMPILER   ${TOOLROOT}/bin/arm-linux-gnueabihf-gcc)
SET(CMAKE_CXX_COMPILER ${TOOLROOT}/bin/arm-linux-gnueabihf-g++)

SET(FLAGS "-Wl,-rpath-link,${PIROOT}/opt/vc/lib -Wl,-rpath-link,${PIROOT}/lib/arm-linux-gnueabihf -Wl,-rpath-link,${PIROOT}/usr/lib/arm-linux-gnueabihf -Wl,-rpath-link,${PIROOT}/usr/local/lib")

UNSET(CMAKE_C_FLAGS CACHE)
UNSET(CMAKE_CXX_FLAGS CACHE)

SET(CMAKE_CXX_FLAGS ${FLAGS} CACHE STRING "" FORCE)
SET(CMAKE_C_FLAGS ${FLAGS} CACHE STRING "" FORCE)

SET(CMAKE_SYSROOT ${PIROOT})
SET(CMAKE_FIND_ROOT_PATH ${PIROOT})


# search for programs in the build host directories
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
# for libraries and headers in the target directories
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

Where I had a pidev folder in my home directory and under that piroot had a copy of /usr /opt /etc and /lib from my pi host, and pitools is a clone of the toolchain from GitHub I reference above.

My CMakeLists.txt file for my project was:

cmake_minimum_required(VERSION 2.8)
project( PiCamCVTest )
SET(COMPILE_DEFINITIONS -Werror)

include_directories(SYSTEM ${PIROOT}/opt/vc/include ${PIROOT}/opt/vc/include/interface/vcos/pthreads ${PIROOT}/opt/vc/include/interface/vmcs_host/linux )
link_directories( ${PIROOT}/opt/vc/lib )
add_executable(PiCamCVTest main.cpp camera.cpp cameracontrol.cpp graphics.cpp)

target_link_libraries(PiCamCVTest libmmal_core.so libmmal_util.so libmmal_vc_client.so libvcos.so librt.so libbcm_host.so GLESv2 EGL libopencv_core.so libopencv_imgproc.so)

Hope this helps.

Answer 2

You can cross compile Qt (c++) with OpenCV to the raspberry pi following this link: http://aplacetogeek.wordpress.com/qt-opencv-v4l-cross-compiling-raspberry-pi-beagle-bone/

This link should give you all the needed information on how to make your system able to cross compile for the raspberry pi. When you've set up everything the way the link says, I think you can also use the opencv library's to cross compile c++ without Qt if you prefer.