交叉编译-2：跨平台交叉编译FFmpeg库（Android、IOS、S2L）

一、Android平台

     1. 进入网址https://ffmpeg.org/download.html，下载 FFmpeg压缩包。

     2. 修改FFmpeg的configure。由于编译出来的动态库文件名的版本号在.so之后（例如“libavcodec.so.5.100.1”），而android平台不能识别这样文件名，所以需要修改这种文件名。在configure文件中找到下面几行代码：

 

SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'  
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'  
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'  
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR)$(SLIBNAME)' 

替换为：

 

 

SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'  
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'  
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'  
SLIB_INSTALL_LINKS='$(SLIBNAME)'

        3. 新建build_ffmpeg.sh脚本，执行脚本（./build_ffmpeg.sh）

 

export NDK=/tmp/android-ndk-r14b
export SYSROOT=$NDK/platforms/android-16/arch-arm/
export TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
PREFIX=./output
ADDI_CFLAGS="-marm"

function build_ffmpeg
{
	echo "start build ffmpeg $ARCH"
	./configure --target-os=linux \
	--prefix=$PREFIX \
	--arch=$ARCH \
	--enable-shared \
	--enable-static \
	--disable-yasm \
	--disable-asm \
	--disable-ffmpeg \
	--disable-ffplay \
	--disable-ffprobe \
	--disable-ffserver \
	--disable-doc \
    --disable-symver \
    --target-os=linux \
    --arch=arm \
	--enable-cross-compile \
	--enable-pic --enable-memalign-hack \
	--disable-encoders --enable-encoder=libx264 --enable-encoder=aac \
	--disable-decoders --enable-decoder=h264 --enable-decoder=aac \
	--disable-demuxers --enable-demuxer=mpegts \
    --enable-gpl --disable-zlib --enable-nonfree --disable-debug \
	--cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
	--sysroot=$SYSROOT \
	--extra-cflags="-Os -fpic $ADDI_CFLAGS" \
    --extra-ldflags="$ADDI_LDFLAGS" 
    $ADDITIONAL_CONFIGURE_FLAG
	make clean
        make
       make install

	echo "build finished $ARCH"
}

build_ffmpeg

 

一、IOS平台

编译准备：

iPhone 6之后的编译平台可选择为arm64，选择早期平台可能会影响性能。

下载脚本：
    gas-preprocessor.pl
    build-x264.sh
    build-ffmpeg.sh

1.下载libx264，在libx264文件夹外执行build-x264.sh脚本便会编译生成x264库。

 

#build-x264.sh
#!/bin/sh

CONFIGURE_FLAGS="--enable-static --enable-pic --disable-cli"

ARCHS="arm64 x86_64 i386 armv7 armv7s"

# directories
SOURCE="x264"
FAT="x264-iOS"

SCRATCH="scratch-x264"
# must be an absolute path
THIN=`pwd`/"thin-x264"

# the one included in x264 does not work; specify full path to working one
GAS_PREPROCESSOR=/usr/local/bin/gas-preprocessor.pl

COMPILE="y"
LIPO="y"

if [ "$*" ]
then
	if [ "$*" = "lipo" ]
	then
		# skip compile
		COMPILE=
	else
		ARCHS="$*"
		if [ $# -eq 1 ]
		then
			# skip lipo
			LIPO=
		fi
	fi
fi

if [ "$COMPILE" ]
then
	CWD=`pwd`
	for ARCH in $ARCHS
	do
		echo "building $ARCH..."
		mkdir -p "$SCRATCH/$ARCH"
		cd "$SCRATCH/$ARCH"
		CFLAGS="-arch $ARCH"
                ASFLAGS=

		if [ "$ARCH" = "i386" -o "$ARCH" = "x86_64" ]
		then
		    PLATFORM="iPhoneSimulator"
		    CPU=
		    if [ "$ARCH" = "x86_64" ]
		    then
		    	CFLAGS="$CFLAGS -mios-simulator-version-min=7.0"
		    	HOST=
		    else
		    	CFLAGS="$CFLAGS -mios-simulator-version-min=5.0"
			HOST="--host=i386-apple-darwin"
		    fi
		else
		    PLATFORM="iPhoneOS"
		    if [ $ARCH = "arm64" ]
		    then
		        HOST="--host=aarch64-apple-darwin"
			XARCH="-arch aarch64"
		    else
		        HOST="--host=arm-apple-darwin"
			XARCH="-arch arm"
		    fi
                    CFLAGS="$CFLAGS -fembed-bitcode -mios-version-min=7.0"
                    ASFLAGS="$CFLAGS"
		fi

		XCRUN_SDK=`echo $PLATFORM | tr '[:upper:]' '[:lower:]'`
		CC="xcrun -sdk $XCRUN_SDK clang"
		if [ $PLATFORM = "iPhoneOS" ]
		then
		    export AS="gas-preprocessor.pl $XARCH -- $CC"
		else
		    export -n AS
		fi
		CXXFLAGS="$CFLAGS"
		LDFLAGS="$CFLAGS"

		CC=$CC $CWD/$SOURCE/configure \
		    $CONFIGURE_FLAGS \
		    $HOST \
		    --extra-cflags="$CFLAGS" \
		    --extra-asflags="$ASFLAGS" \
		    --extra-ldflags="$LDFLAGS" \
		    --prefix="$THIN/$ARCH" || exit 1

		mkdir extras
		ln -s $GAS_PREPROCESSOR extras

		make -j3 install || exit 1
		cd $CWD
	done
fi

if [ "$LIPO" ]
then
	echo "building fat binaries..."
	mkdir -p $FAT/lib
	set - $ARCHS
	CWD=`pwd`
	cd $THIN/$1/lib
	for LIB in *.a
	do
		cd $CWD
		lipo -create `find $THIN -name $LIB` -output $FAT/lib/$LIB
	done

	cd $CWD
	cp -rf $THIN/$1/include $FAT
fi

 

2.默认情况下ffmpeg编译脚本是配置的是不使用libx264（主要在于libx264的文件路径是否配置)，配置x264库的路径为libx264生成的路径x264-iOS。
3.修改build-ffmpeg.sh脚本中的版本号执行时会自动下载源码。

4.执行build-ffmpeg.sh

 

#build-ffmpeg.sh
#!/bin/sh

# directories
SOURCE="ffmpeg-2.5.3"
#SOURCE="./"
FAT="FFmpeg-iOS"

SCRATCH="scratch"
# must be an absolute path
THIN=`pwd`/"thin"

# absolute path to x264 library
#X264=`pwd`/fat-x264

#FDK_AAC=`pwd`/../fdk-aac-build-script-for-iOS/fdk-aac-ios

CONFIGURE_FLAGS="--enable-cross-compile --disable-debug --disable-programs \
                 --disable-doc --enable-pic"

if [ "$X264" ]
then
	CONFIGURE_FLAGS="$CONFIGURE_FLAGS --enable-gpl --enable-libx264"
fi

if [ "$FDK_AAC" ]
then
	CONFIGURE_FLAGS="$CONFIGURE_FLAGS --enable-libfdk-aac"
fi

# avresample
#CONFIGURE_FLAGS="$CONFIGURE_FLAGS --enable-avresample"

ARCHS="arm64 armv7 x86_64 i386"

COMPILE="y"
LIPO="y"

DEPLOYMENT_TARGET="6.0"

if [ "$*" ]
then
	if [ "$*" = "lipo" ]
	then
		# skip compile
		COMPILE=
	else
		ARCHS="$*"
		if [ $# -eq 1 ]
		then
			# skip lipo
			LIPO=
		fi
	fi
fi

if [ "$COMPILE" ]
then
	if [ ! `which yasm` ]
	then
		echo 'Yasm not found'
		if [ ! `which brew` ]
		then
			echo 'Homebrew not found. Trying to install...'
                        ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" \
				|| exit 1
		fi
		echo 'Trying to install Yasm...'
		brew install yasm || exit 1
	fi
	if [ ! `which gas-preprocessor.pl` ]
	then
		echo 'gas-preprocessor.pl not found. Trying to install...'
		(curl -L https://github.com/libav/gas-preprocessor/raw/master/gas-preprocessor.pl \
			-o /usr/local/bin/gas-preprocessor.pl \
			&& chmod +x /usr/local/bin/gas-preprocessor.pl) \
			|| exit 1
	fi

	if [ ! -r $SOURCE ]
	then
		echo 'FFmpeg source not found. Trying to download...'
		curl http://www.ffmpeg.org/releases/$SOURCE.tar.bz2 | tar xj \
			|| exit 1
	fi

	CWD=`pwd`
	for ARCH in $ARCHS
	do
		echo "building $ARCH..."
		mkdir -p "$SCRATCH/$ARCH"
		cd "$SCRATCH/$ARCH"

		CFLAGS="-arch $ARCH"
		if [ "$ARCH" = "i386" -o "$ARCH" = "x86_64" ]
		then
		    PLATFORM="iPhoneSimulator"
		    CFLAGS="$CFLAGS -mios-simulator-version-min=$DEPLOYMENT_TARGET"
		else
		    PLATFORM="iPhoneOS"
		    CFLAGS="$CFLAGS -mios-version-min=$DEPLOYMENT_TARGET -fembed-bitcode"
		    if [ "$ARCH" = "arm64" ]
		    then
		        EXPORT="GASPP_FIX_XCODE5=1"
		    fi
		fi

		XCRUN_SDK=`echo $PLATFORM | tr '[:upper:]' '[:lower:]'`
		CC="xcrun -sdk $XCRUN_SDK clang"

		# force "configure" to use "gas-preprocessor.pl" (FFmpeg 3.3)
		if [ "$ARCH" = "arm64" ]
		then
		    AS="gas-preprocessor.pl -arch aarch64 -- $CC"
		else
		    AS="$CC"
		fi

		CXXFLAGS="$CFLAGS"
		LDFLAGS="$CFLAGS"
		if [ "$X264" ]
		then
			CFLAGS="$CFLAGS -I$X264/include"
			LDFLAGS="$LDFLAGS -L$X264/lib"
		fi
		if [ "$FDK_AAC" ]
		then
			CFLAGS="$CFLAGS -I$FDK_AAC/include"
			LDFLAGS="$LDFLAGS -L$FDK_AAC/lib"
		fi

		TMPDIR=${TMPDIR/%\/} $CWD/$SOURCE/configure \
		    --target-os=darwin \
		    --arch=$ARCH \
		    --cc="$CC" \
		    --as="$AS" \
		    $CONFIGURE_FLAGS \
		    --extra-cflags="$CFLAGS" \
		    --extra-ldflags="$LDFLAGS" \
		    --prefix="$THIN/$ARCH" \
                    --enable-pthreads \
                    --extra-cflags="-fPIC" \
                    --enable-pic --disable-symver --enable-memalign-hack  \
                    --disable-encoders --enable-encoder=libx264 --enable-encoder=aac \
                    --disable-decoders --enable-decoder=h264 --enable-decoder=aac \
                    --disable-demuxers --enable-demuxer=mpegts \
                    --enable-gpl  --disable-zlib --disable-iconv \
                    --extra-cflags='-fPIC' --extra-cxxflags=-D__STDC_LIMIT_MACROS \
                    --enable-nonfree \
		|| exit 1

		make -j3 install $EXPORT || exit 1
		cd $CWD
	done
fi

if [ "$LIPO" ]
then
	echo "building fat binaries..."
	mkdir -p $FAT/lib
	set - $ARCHS
	CWD=`pwd`
	cd $THIN/$1/lib
	for LIB in *.a
	do
		cd $CWD
		echo lipo -create `find $THIN -name $LIB` -output $FAT/lib/$LIB 1>&2
		lipo -create `find $THIN -name $LIB` -output $FAT/lib/$LIB || exit 1
	done

	cd $CWD
	cp -rf $THIN/$1/include $FAT
fi

echo Done

一、S2L平台

 

执行以下命令：

 

./configure --prefix=/home/ffmpeg-2.5.3-amba/amba-lib --arch=arm --enable-cross-compile --target-os=linux  --cc=/opt/arm/linaro-multilib-2014.06-gcc4.9/bin/arm-linux-gnueabihf-gcc --cxx=/opt/arm/linaro-multilib-2014.06-gcc4.9/bin/arm-linux-gnueabihf-g++ --enable-pthreads --extra-cflags="-fPIC" --enable-shared --enable-static --enable-pic --disable-symver --enable-memalign-hack --disable-encoders --enable-encoder=libx264 --enable-encoder=aac --disable-decoders --enable-decoder=h264 --enable-decoder=aac --disable-demuxers --enable-demuxer=mpegts --enable-gpl --enable-libx264 --enable-libfaac --disable-zlib --extra-cflags='-fPIC' --extra-cxxflags=-D__STDC_LIMIT_MACROS --enable-nonfree --disable-debug --extra-cflags=-I/usr/local/include --extra-ldflags=-L/usr/local/lib --extra-libs=-ldl