如何通过其他模块交叉编译Raspberry Pi的OpenCV(highgui ...) [英] How do I cross compile OpenCV for the Raspberry Pi with additional modules (highgui...)
问题描述
我的目标是在Ubuntu 16.04主机上使用CMake对Raspberry Pi的OpenCV进行交叉编译.问题位于CMake工具链文件中，该文件无法正确处理编译过程.一旦pkg-config起作用，就会出现许多致命错误:没有这样的文件或目录"错误(例如致命错误:gtk/gtk.h:没有这样的文件或目录).
My goal is to cross-compile OpenCV for Raspberry Pi with CMake on an Ubuntu 16.04 Host. The Problem lies within the CMake toolchain file which is unable to handle the compilation process correctly. As soon as pkg-config comes into play, a lot of "fatal error: No such file or directory" errors arise (e.g. "fatal error: gtk/gtk.h: No such file or directory).
我发现带有包含丢失文件的目录的其他"-isystem"标志似乎在某种程度上有所帮助，但我怀疑这是否是解决这些错误的正确方法.
I figured out that further "-isystem" flags with the directories containing the missing files seem to help in some way, but I doubt that this is the right way to address these errors.
只要注释掉"PKG_CONFIG"-东西，工具链文件就可以工作.这将导致pkg-config找不到"libgtk2.0"，这是OpenCV的highgui模块所需的，并且在没有highgui支持的情况下进行构建.
The toolchain file works, as long as the "PKG_CONFIG"-stuff is commented out. This causes pkg-config not to find "libgtk2.0", which is needed for OpenCV's highgui module and builds without highgui-support.
有关工具链的一些想法来自此处:
Some ideas for the toolchain are from here:
- Cmake cross compile cant find library
- Raspberry Pi Beginners Guide
- Cross compile opencv project on Ubuntu for Raspberry Pi
build-toolchain.sh
#!/bin/bash
# apt -y install lib32z1 libstdc++6:i386 git qemu-user proot cmake pkg-config
MOUNT_DIR=/mnt/rasp-pi-rootfs
TEMP_DIR=/tmp/build
RASPBIAN_IMG_ZIP=raspbian-jessie.zip
TOOLCHAIN=gcc-linaro-arm-linux-gnueabihf-raspbian-x64
CMAKE_TOOLCHAIN_FILE=rpi-toolchain.cmake
############################################################################
RASPBIAN_IMG=${TEMP_DIR}/$(unzip -Z1 $RASPBIAN_IMG_ZIP)
rm -rf $TEMP_DIR
mkdir $TEMP_DIR
cd $TEMP_DIR
#unzip raspbian-img
unzip $RASPBIAN_IMG_ZIP
#resize raspbian-img
LOOP_DEVICE=$(losetup -f)
RASPBIAN_PARTITION_BOOT=${LOOP_DEVICE}p1
RASPBIAN_PARTITION_SYSTEM=${LOOP_DEVICE}p2
truncate -s +500M $RASPBIAN_IMG
losetup $LOOP_DEVICE $RASPBIAN_IMG
parted $LOOP_DEVICE resizepart 2 100%
#wait until auto-mounted
umount $RASPBIAN_PARTITION_BOOT
umount $RASPBIAN_PARTITION_SYSTEM
e2fsck -f $RASPBIAN_PARTITION_SYSTEM
resize2fs $RASPBIAN_PARTITION_SYSTEM
#mount raspbian-img
mkdir -p $MOUNT_DIR
mount $RASPBIAN_PARTITION_SYSTEM $MOUNT_DIR
#fix absolute links
proot -q qemu-arm -S $MOUNT_DIR<<EOF
apt update
apt -y install libjpeg-dev libtiff5-dev libjasper-dev libpng12-dev \
libavcodec-dev libavformat-dev libswscale-dev libv4l-dev \
libxvidcore-dev libx264-dev \
libgtk2.0-dev libatlas-base-dev gfortran
apt -y install symlinks
symlinks -cr /usr/lib
EOF
wget -O opencv.zip https://codeload.github.com/Itseez/opencv/zip/2.4.13
unzip opencv.zip
cd opencv-*
mkdir build
cd build
cmake -D CMAKE_TOOLCHAIN_FILE=$CMAKE_TOOLCHAIN_FILE -D PIROOT=$MOUNT_DIR -D TOOLROOT=$TOOLCHAIN -D CMAKE_BUILD_TYPE=Release -D WITH_V4L=ON -D WITH_OPENGL=ON ..
make -j $(nproc)
make install
sync; umount $MOUNT_DIR
losetup -d $LOOP_DEVICE
rpi-toolchain.cmake
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_VERSION 1)
set(CMAKE_SYSTEM_PROCESSOR arm)
set(CMAKE_C_COMPILER ${TOOLROOT}/bin/arm-linux-gnueabihf-gcc)
set(CMAKE_CXX_COMPILER ${TOOLROOT}/bin/arm-linux-gnueabihf-g++)
set(CMAKE_SYSROOT ${PIROOT})
set(CMAKE_FIND_ROOT_PATH ${PIROOT})
unset(ENV{PKG_CONFIG_DIR})
set(ENV{PKG_CONFIG_LIBDIR} "$ENV{PKG_CONFIG_LIBDIR}:${PIROOT}/usr/lib/arm-linux-gnueabihf/pkgconfig:${PIROOT}/usr/share/pkgconfig:${PIROOT}/usr/lib/pkgconfig")
set(ENV{PKG_CONFIG_SYSROOT_DIR} "${PIROOT}")
set(FLAGS "-isystem ${PIROOT}/usr/include/arm-linux-gnueabihf")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${FLAGS}" CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${FLAGS}" CACHE STRING "" FORCE)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
set(CMAKE_INSTALL_PREFIX ${PIROOT}/usr/local)
推荐答案
知道了.问题是在rpi-toolchain.cmake文件中设置了PKG_CONFIG-vars，这是行不通的.必须通过export将它们添加到环境中.
Got it. The Problem was the setting of PKG_CONFIG-vars within the rpi-toolchain.cmake file, this does not work .They have to be added to the environment with export:
...
export PKG_CONFIG_SYSROOT_DIR=${MOUNT_DIR}
export PKG_CONFIG_LIBDIR=${MOUNT_DIR}/usr/lib/arm-linux-gnueabihf/pkgconfig:${MOUNT_DIR}/usr/share/pkgconfig:${MOUNT_DIR}/usr/lib/pkgconfig
export PKG_CONFIG_DIR=
cmake -D CMAKE_TOOLCHAIN_FILE=$CMAKE_TOOLCHAIN_FILE -D PIROOT=$MOUNT_DIR -D TOOLROOT=$TOOLCHAIN -D CMAKE_BUILD_TYPE=Release -D WITH_V4L=ON -D WITH_OPENGL=ON ..
make -j $(nproc)
我不记得这里的实际问题是什么，但是用ENV{}设置pkg-config变量是可行的，而不是罪魁祸首.
edit: I don't remember what the actual problem was here, but setting pkg-config variables with ENV{} works and was not the culprit.
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