compile ffmpeg for armv7 armv7s[通俗易懂]

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1.下载ffmpeg

git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg

2.下载gas-preprocessor

地址： https://github.com/yuvi/gas-preprocessor

下载完后把gas-preprocessor.pl 复制到 /usr/bin/ 目录下，修改权限  chmod 777

3.解压ffmpeg，并进入ffmpeg文件夹：

a.编译armv7

./configure –cc=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc –as=’/usr/bin/gas-preprocessor.pl /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc’ –sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk –extra-ldflags=-L/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/usr/lib/system –target-os=darwin –arch=arm –cpu=cortex-a8 –extra-cflags=’-arch armv7′ –extra-ldflags=’-arch armv7′ –extra-cflags=’-mfpu=neon’ –extra-cflags=’-mfloat-abi=softfp’ –enable-pic –enable-cross-compile –enable-ffmpeg  –enable-decoder=h264 –disable-doc

b.编译完后，make , sudo make install

c.可以在/usr/local/目录下看到lib inlucde文件夹都有新增文件，将/usr/local/lib/下的.a文件复制到随便新建一个文件夹，命名文件夹armv7

4.编译armv7s

a. ./configure –disable-doc –disable-ffmpeg –disable-ffplay –disable-ffserver –enable-cross-compile –arch=arm –target-os=darwin –cc=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc –as=’gas-preprocessor/gas-preprocessor.pl /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc’ –sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk –cpu=cortex-a8 –extra-cflags=’-arch armv7s’ –extra-ldflags=’-arch armv7s -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk’ –enable-pic –enable-decoder=rawvideo –disable-asm

b.编译完后，make , sudo make install

c.可以在/usr/local/目录下看到lib inlucde文件夹都有新增文件，将/usr/local/lib/下的.a文件复制到随便新建一个文件夹，命名文件夹armv7s

5.合并两个版本

a.去掉重复的log2_tab.o

ar -dv armv7s/libavutil.a log2_tab.o

ar -dv armv7/libavutil.a log2_tab.o

ar -dv armv7s/libswresample.a log2_tab.o

ar -dv armv7/libswresample.a log2_tab.o

ar -dv armv7s/libavformat.a log2_tab.o

ar -dv armv7/libavformat.a log2_tab.o

b.合并

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libavcodec.a -arch armv7s armv7s/libavcodec.a -output libavcodec.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libavdevice.a -arch armv7s armv7s/libavdevice.a -output libavdevice.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libavfilter.a -arch armv7s armv7s/libavfilter.a -output libavfilter.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libavformat.a -arch armv7s armv7s/libavformat.a -output libavformat.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libavutil.a -arch armv7s armv7s/libavutil.a -output libavutil.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libswresample.a -arch armv7s armv7s/libswresample.a -output libswresample.a

xcrun -sdk iphoneos lipo -create -arch armv7 armv7/libswscale.a -arch armv7s armv7s/libswscale.a -output libswscale.a

6.添加到xcode

新建文件夹ffmpeg，将合并后的.a文件和/usr/local/include/*的文件复制到ffmpeg夹下，把ffmpeg复制到工程下，并add

7.在工程的build phase引入libz.dylib和libbz2.dylib两个库

8.在Build Settings, 搜索header search paths, 加上ffmpeg

编译运行。。