MacOS(M1)交叉编译安卓版本OpenCV(附带FFmpeg)
1 编译FFmpeg
1.1 准备FFmpeg源码
git clone https://gitee.com/mirrors/ffmpeg.git
git checkout -b v4.2 origin/release/4.2 #切换到4.2分之，最新的不能适配opencv
1.2 构建编译脚本
在源码目录构建如下脚本文件，并执行
#!/bin/bash
#你的NDK路径
NDK=/Users/gauss/Library/Android/sdk/ndk/21.4.7075529
TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/darwin-x86_64
API=21
echo "进入FFmpeg编译脚本"
function build_android
{
echo "Compiling FFmpeg for $CPU"
./configure \
--prefix=$PREFIX \
--libdir=$LIB_DIR \
--enable-shared \
--disable-static \
--enable-jni \
--disable-doc \
--disable-symver \
--disable-programs \
--target-os=android \
--arch=$ARCH \
--cpu=$CPU \
--cc=$CC \
--cxx=$CXX \
--enable-cross-compile \
--sysroot=$SYSROOT \
--extra-cflags="-Os -fpic $OPTIMIZE_CFLAGS" \
--extra-ldflags="$ADDI_LDFLAGS" \
--disable-asm \
$COMMON_FF_CFG_FLAGS
make clean
make -j8 # 这里是定义用几个CPU编译
make install
echo "The Compilation of FFmpeg for $CPU is completed"
}
#################### armv7-a ################################
echo "开始编译FFmpeg(armeabi-v7a)"
OUTPUT_FOLDER="armeabi-v7a"
ARCH="arm"
CPU="armv7-a"
TOOL_CPU_NAME=armv7a
TOOL_PREFIX="$TOOLCHAIN/bin/arm-linux-androideabi"
CC="$TOOLCHAIN/bin/armv7a-linux-androideabi$API-clang"
CXX="$TOOLCHAIN/bin/armv7a-linux-androideabi$API-clang++"
SYSROOT="$NDK/toolchains/llvm/prebuilt/darwin-x86_64/sysroot"
PREFIX="${PWD}/android/$OUTPUT_FOLDER"
LIB_DIR="${PWD}/android/libs/$OUTPUT_FOLDER"
OPTIMIZE_CFLAGS="-march=$CPU"
build_android
#################### armv8-a ################################
echo "开始编译FFmpeg(arm64-v8a)"
OUTPUT_FOLDER="arm64-v8a"
ARCH=arm64
CPU="armv8-a"
TOOL_CPU_NAME=aarch64
TOOL_PREFIX="$TOOLCHAIN/bin/$TOOL_CPU_NAME-linux-android"
CC="$TOOL_PREFIX$API-clang"
CXX="$TOOL_PREFIX$API-clang++"
SYSROOT="$NDK/toolchains/llvm/prebuilt/darwin-x86_64/sysroot"
PREFIX="${PWD}/android/$OUTPUT_FOLDER"
LIB_DIR="${PWD}/android/libs/$OUTPUT_FOLDER"
OPTIMIZE_CFLAGS="-march=$CPU"
build_android
#################### x86 ################################
# echo "开始编译FFmpeg(x86)"
# OUTPUT_FOLDER="x86"
# ARCH="x86"
# CPU="x86"
# TOOL_CPU_NAME="i686"
# TOOL_PREFIX="$TOOLCHAIN/bin/${TOOL_CPU_NAME}-linux-android"
# CC="$TOOL_PREFIX$API-clang"
# CXX="$TOOL_PREFIX$API-clang++"
# SYSROOT="$NDK/toolchains/llvm/prebuilt/darwin-x86_64/sysroot"
# PREFIX="${PWD}/android/$OUTPUT_FOLDER"
# LIB_DIR="${PWD}/android/libs/$OUTPUT_FOLDER"
# OPTIMIZE_CFLAGS="-march=i686 -mtune=intel -mssse3 -mfpmath=sse -m32"
# build_android
#################### x86_64 ################################
# echo "开始编译FFmpeg(x86_64)"
# OUTPUT_FOLDER="x86_64"
# ARCH="x86_64"
# CPU="x86-64"
# TOOL_CPU_NAME="x86_64"
# TOOL_PREFIX="$TOOLCHAIN/bin/${TOOL_CPU_NAME}-linux-android"
# CC="$TOOL_PREFIX$API-clang"
# CXX="$TOOL_PREFIX$API-clang++"
# SYSROOT="$NDK/toolchains/llvm/prebuilt/darwin-x86_64/sysroot"
# PREFIX="${PWD}/android/$OUTPUT_FOLDER"
# LIB_DIR="${PWD}/android/libs/$OUTPUT_FOLDER"
# OPTIMIZE_CFLAGS="-march=$CPU"
# build_android
编译好之后得到库文件
添加ffmpeg-config.cmake文件，内容如下(针对armv7)
set(ffmpeg_path "${CMAKE_CURRENT_LIST_DIR}")
message("ffmpeg_path: ${ffmpeg_path}")
set(FFMPEG_LIBDIR "/opt/code/ffmpeg/android/libs/armeabi-v7a")
set(FFMPEG_INCLUDE_DIRS "/opt/code/ffmpeg/android/armeabi-v7a/include")
# library names
set(FFMPEG_LIBRARIES
${FFMPEG_LIBDIR}/libavformat.so
${FFMPEG_LIBDIR}/libavdevice.so
${FFMPEG_LIBDIR}/libavcodec.so
${FFMPEG_LIBDIR}/libavutil.so
${FFMPEG_LIBDIR}/libswscale.so
${FFMPEG_LIBDIR}/libswresample.so
${FFMPEG_LIBDIR}/libavfilter.so
)
# found status
set(FFMPEG_libavformat_FOUND TRUE)
set(FFMPEG_libavdevice_FOUND TRUE)
set(FFMPEG_libavcodec_FOUND TRUE)
set(FFMPEG_libavutil_FOUND TRUE)
set(FFMPEG_libswscale_FOUND TRUE)
set(FFMPEG_libswresample_FOUND TRUE)
set(FFMPEG_libavfilter_FOUND TRUE)
# library versions, 注意这几个变量，一定要设置为全局CACHE变量
set(FFMPEG_libavutil_VERSION 56.31.100 CACHE INTERNAL "FFMPEG_libavutil_VERSION") # info
set(FFMPEG_libavcodec_VERSION 58.54.100 CACHE INTERNAL "FFMPEG_libavcodec_VERSION") # info
set(FFMPEG_libavformat_VERSION 58.29.100 CACHE INTERNAL "FFMPEG_libavformat_VERSION") # info
set(FFMPEG_libavdevice_VERSION 58.8.100 CACHE INTERNAL "FFMPEG_libavdevice_VERSION") # info
set(FFMPEG_libavfilter_VERSION 7.57.100 CACHE INTERNAL "FFMPEG_libavfilter_VERSION") # info
set(FFMPEG_libswscale_VERSION 5.5.100 CACHE INTERNAL "FFMPEG_libswscale_VERSION") # info
set(FFMPEG_libswresample_VERSION 3.5.100 CACHE INTERNAL "FFMPEG_libswresample_VERSION") # info
set(FFMPEG_FOUND TRUE)
set(FFMPEG_LIBS ${FFMPEG_LIBRARIES})
status(" #################################### FFMPEG:" FFMPEG_FOUND THEN "YES (find_package)" ELSE "NO (find_package)")
status(" avcodec:" FFMPEG_libavcodec_VERSION THEN "YES (${FFMPEG_libavcodec_VERSION})" ELSE NO)
status(" avformat:" FFMPEG_libavformat_VERSION THEN "YES (${FFMPEG_libavformat_VERSION})" ELSE NO)
status(" avutil:" FFMPEG_libavutil_VERSION THEN "YES (${FFMPEG_libavutil_VERSION})" ELSE NO)
status(" swscale:" FFMPEG_libswscale_VERSION THEN "YES (${FFMPEG_libswscale_VERSION})" ELSE NO)
status(" avresample:" FFMPEG_libavresample_VERSION THEN "YES (${FFMPEG_libavresample_VERSION})" ELSE NO)
2 编译 OpenCV
2.1 准备OpenCV源码
git clone https://gitee.com/code-github/opencv_opencv.git
* 4.x f7ac724c5d Merge pull request #21531 from fengyuentau:add_3rdparty_mirrors
git branch -r
origin/2.4
origin/3.4
origin/4.x
origin/5.x
origin/HEAD -> origin/4.x #使用的是4.x分支
origin/master
origin/next
2.2 修改源码根目录下CMakeLists.txt
需要修改两个地方
2.3 执行cmake
需要准备SDk和NDK的路径
cmake -DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK/build/cmake/android.toolchain.cmake -DCMAKE_ANDROID_NDK=$ANDROID_NDK \
-DANDROID_NATIVE_API_LEVEL=android-21 \
-DCMAKE_BUILD_TYPE=Release \
-DCMAKE_INSTALL_PREFIX=/opt/code/opencv-4.x/ \
-DBUILD_JAVA=OFF \
-DANDROID_SDK_TOOLS=$ANDROID_SDK/build-tools/29.0.2 \
-DBUILD_ANDROID_EXAMPLES=OFF \
-DCMAKE_EXPORT_COMPILE_COMMANDS=OFF \
-DBUILD_SHARED_LIBS=ON \
-DWITH_FFMPEG=ON \
-DBUILD_FAT_JAVA_LIB=OFF \
-DOPENCV_GENERATE_PKGCONFIG=ON \
-DOPENCV_FFMPEG_USE_FIND_PACKAGE=ON \
-DOPENCV_FFMPEG_SKIP_BUILD_CHECK=ON \
-DFFMPEG_DIR=/opt/code/ffmpeg/android/ ..
最后可以看到已经关联了FFmpeg
--
-- Video I/O:
-- FFMPEG: YES (find_package)
-- avcodec: YES (58.54.100)
-- avformat: YES (58.29.100)
-- avutil: YES (56.31.100)
-- swscale: YES (5.5.100)
-- avresample: NO
--
-- Parallel framework: pthreads
--
-- Trace: YES (with Intel ITT)
--
-- Other third-party libraries:
-- Custom HAL: YES (carotene (ver 0.0.1))
-- Protobuf: build (3.19.1)
--
-- Python (for build): /opt/homebrew/bin/python3
--
-- Install to: /opt/code/opencv-4.x
2.4 执行编译
make -j10
make install参考：
opencv+ffmpeg编译打包全解指南 - 知乎 (zhihu.com) Android最简单的基于FFmpeg的例子(一)---编译FFmpeg类库 | binglingziyu的博客
Android交叉编译OpenCV+FFmpeg+x264的艰难历程_dreamgyf的博客-CSDN博客