本文记录IOS平台下基于FFmpeg的HelloWorld程序。该示例C语言的源代码来自于《最简单的基于FFMPEG的Helloworld程序》。相关的概念就不再重复记录了。
IOS程序使用FFmpeg类库的说明
IOS应用程序使用FFmpeg类库的流程如下所示。
1. 编译FFmpeg类库
编译IOS的FFmpeg类库需要支持5种架构：armv7、armv7s、arm64、i386、x86_64。其中前面3个是给真机使用的，后面2个是给模拟器使用的。本文记录的FFmpeg类库还支持第三方类库libx264和libfaac，所以在编译之前还要先编译libx264和libfaac的源代码。总体说来，IOS下的类库需要编译成两个版本：thin和fat。每种架构对应一个thin版本的类库，将这些不同架构thin版本的类库合成起来之后，就形成了fat版本的类库。下面简单记录一下编译步骤。编译过程中IOS SDK版本为8.3，FFmpeg版本为2.7.1，faac和x264分别使用了最新版本的源代码。
(1) 第三方库libx264的编译
这一步用于生成支持armv7、armv7s、arm64、i386、x86_64几种架构的fat版本的libx264.a。下面这个脚本可以首先编译生成上面5种架构的thin版本的libx264.a，分成5个文件夹存储于thin-x264文件夹中；然后将这些类库合并成为1个fat版本的libx264.a，存储于fat-x264文件夹中。
build_x264.sh
#!/bin/sh
# LXH,MXY
#
# directories
SOURCE="x264"
FAT="fat-x264"
SCRATCH="scratch-x264"
# must be an absolute path
THIN=`pwd`/"thin-x264"
#This is decided by your SDK version.
SDK_VERSION="8.3"
cd ./x264
#============== simulator ===============
PLATFORM="iPhoneSimulator"
#i386
ARCHS="i386"
export DEVROOT=/Applications/Xcode.app/Contents/Developer/Platforms/${PLATFORM}.platform/Developer
export SDKROOT=$DEVROOT/SDKs/${PLATFORM}${SDK_VERSION}.sdk
export CC=$DEVROOT/usr/bin/gcc
export LD=$DEVROOT/usr/bin/ld
export CXX=$DEVROOT/usr/bin/g++
export LIBTOOL=$DEVROOT/usr/bin/libtool
export HOST=i386-apple-darwin
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
for ARCH in $ARCHS; do
echo "Building $ARCH ......"
make clean
./configure --host=i386-apple-darwin --sysroot=$SDKROOT --prefix="$THIN/$ARCH" --extra-cflags="-arch $ARCH -miphoneos-version-min=6.0" --extra-ldflags="-L$SDKROOT/usr/lib/system -arch $ARCH -miphoneos-version-min=6.0" --enable-pic --enable-static --disable-asm make && make install && make clean
echo "Installed: $DEST/$ARCH"
done
#x86_64
ARCHS="x86_64"
unset DEVROOT
unset SDKROOT
unset CC
unset LD
unset CXX
unset LIBTOOL
unset HOST
unset LDFLAGS
unset CFLAGS
make clean
for ARCH in $ARCHS; do
echo "Building $ARCH ......"
./configure --prefix="$THIN/$ARCH" --enable-pic --enable-static --disable-asm make && make install && make clean
echo "Installed: $DEST/$ARCH"
done
#================ iphone ==================
export PLATFORM="iPhoneOS"
ARCHS="arm64 armv7 armv7s "
export DEVROOT=/Applications/Xcode.app/Contents/Developer
export SDKROOT=$DEVROOT/Platforms/${PLATFORM}.platform/Developer/SDKs/${PLATFORM}${SDK_VERSION}.sdk
#DEVPATH=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS${SDK_VERSION}.sdk
export CC=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
export AS=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/as
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -marm -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
export CXXFLAGS="${COMMONFLAGS} -fvisibility=hidden -fvisibility-inlines-hidden"
for ARCH in $ARCHS; do
echo "Building $ARCH ......"
./configure --host=arm-apple-darwin --sysroot=$DEVPATH --prefix="$THIN/$ARCH" --extra-cflags="-arch $ARCH" --extra-ldflags="-L$DEVPATH/usr/lib/system -arch $ARCH" --enable-pic --enable-static --disable-asm
make && make install && make clean
echo "Installed: $DEST/$ARCH"
done
cd ..
#================ fat lib ===================
ARCHS="armv7 armv7s i386 x86_64 arm64"
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 $FAT
(2) 第三方库libfaac的编译
这一步用于生成支持armv7、armv7s、arm64、i386、x86_64几种架构的fat版本的libfaac.a。下面这个脚本可以首先编译生成上面5种架构的thin版本的libfaac.a，分成5个文件夹存储于fat-faac中；然后将这些类库合并成为1个fat版本的libfaac.a，存储于fat-faac中。
build_faac.sh
#!/bin/sh cd ./faac make distclean cd .. CONFIGURE_FLAGS="--enable-static --with-pic" ARCHS="arm64 armv7s x86_64 i386 armv7" # directories SOURCE="faac" FAT="fat-faac" SCRATCH="scratch-faac" # must be an absolute path THIN=`pwd`/"thin-faac" COMPILE="y" LIPO="y" if [ "$*" ] 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/$ARCH" if [ "$ARCH" = "i386" -o "$ARCH" = "x86_64" ] then PLATFORM="iPhoneSimulator" CPU= if [ "$ARCH" = "x86_64" ] then SIMULATOR="-mios-simulator-version-min=7.0" HOST= else SIMULATOR="-mios-simulator-version-min=5.0" HOST="--host=i386-apple-darwin" fi else PLATFORM="iPhoneOS" if [ $ARCH = "armv7s" ] then CPU="--cpu=swift" else CPU= fi SIMULATOR= HOST="--host=arm-apple-darwin" fi XCRUN_SDK=`echo $PLATFORM | tr ‘[:upper:]‘ ‘[:lower:]‘` CC="xcrun -sdk $XCRUN_SDK clang -Wno-error=unused-command-line-argument-hard-error-in-future" AS="/usr/local/bin/gas-preprocessor.pl $CC" CFLAGS="-arch $ARCH $SIMULATOR" CXXFLAGS="$CFLAGS" LDFLAGS="$CFLAGS" CC=$CC CFLAGS=$CXXFLAGS LDFLAGS=$LDFLAGS CPPFLAGS=$CXXFLAGS CXX=$CC CXXFLAGS=$CXXFLAGS $CWD/$SOURCE/configure $CONFIGURE_FLAGS $HOST --prefix="$THIN/$ARCH" --disable-shared --without-mp4v2 make clean && make && make install-strip cd $CWD done fi #================ fat lib =================== 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 $FAT
(3) 编译armv7版本FFmpeg类库
这一步用于生成支持armv7架构的thin版本的FFmpeg类库，存储于thin-ffmpeg/armv7文件夹中。脚本如下所示。
build_ffmpeg_demo_armv7.sh
#!/bin/sh
# LXH,MXY modified
cd ffmpeg
PLATFORM="iPhoneOS"
INSTALL="thin-ffmpeg"
SDK_VERSION="8.3"
# libx264
export X264ROOT=../thin-x264/armv7
export X264LIB=$X264ROOT/lib
export X264INCLUDE=$X264ROOT/include
# libfaac
export FAACROOT=../thin-faac/armv7
export FAACLIB=$FAACROOT/lib
export FAACINCLUDE=$FAACROOT/include
export DEVROOT=/Applications/Xcode.app/Contents/Developer
export SDKROOT=$DEVROOT/Platforms/${PLATFORM}.platform/Developer/SDKs/${PLATFORM}${SDK_VERSION}.sdk
export CC=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
export AS=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/as
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -marm -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
export CXXFLAGS="${COMMONFLAGS} -fvisibility=hidden -fvisibility-inlines-hidden"
echo "Building armv7..."
make clean
./configure --cpu=cortex-a9 --extra-cflags=‘-I$X264INCLUDE -I$FAACINCLUDE -arch armv7 -miphoneos-version-min=5.0 -mthumb‘ --extra-ldflags=‘-L$X264LIB -L$FAACLIB -arch armv7 -miphoneos-version-min=5.0‘ --enable-cross-compile --arch=arm --disable-iconv --target-os=darwin --cc=${CC} --disable-asm --sysroot=${SDKROOT} --prefix=../${INSTALL}/armv7 --enable-gpl --enable-nonfree --enable-version3 --disable-bzlib --enable-small --disable-vda --disable-encoders --enable-libx264 --enable-libfaac --enable-encoder=libx264 --enable-encoder=libfaac --disable-muxers --enable-muxer=flv --enable-muxer=mov --enable-muxer=ipod --enable-muxer=mpegts --enable-muxer=psp --enable-muxer=mp4 --enable-muxer=avi --disable-decoders --enable-decoder=aac --enable-decoder=aac_latm --enable-decoder=h264 --enable-decoder=mpeg4 --disable-demuxers --enable-demuxer=flv --enable-demuxer=h264 --enable-demuxer=mpegts --enable-demuxer=avi --enable-demuxer=mpc --enable-demuxer=mov --disable-parsers --enable-parser=aac --enable-parser=ac3 --enable-parser=h264 --disable-protocols --enable-protocol=file --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=udp --disable-bsfs --enable-bsf=aac_adtstoasc --enable-bsf=h264_mp4toannexb --disable-devices --disable-debug --disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-ffserver --disable-debug
make
make install
cd ..
(4) 编译armv7s版本FFmpeg类库
这一步用于生成支持armv7s架构的thin版本的FFmpeg类库，存储于thin-ffmpeg/armv7s文件夹中。脚本如下所示。
build_ffmpeg_demo_armv7s.sh
#!/bin/sh
# LXH,MXY modified
cd ffmpeg
PLATFORM="iPhoneOS"
INSTALL="thin-ffmpeg"
SDK_VERSION="8.3"
# libx264
export X264ROOT=../thin-x264/armv7s
export X264LIB=$X264ROOT/lib
export X264INCLUDE=$X264ROOT/include
# libfaac
export FAACROOT=../thin-faac/armv7s
export FAACLIB=$FAACROOT/lib
export FAACINCLUDE=$FAACROOT/include
export DEVROOT=/Applications/Xcode.app/Contents/Developer
export SDKROOT=$DEVROOT/Platforms/${PLATFORM}.platform/Developer/SDKs/${PLATFORM}${SDK_VERSION}.sdk
export CC=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
export AS=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/as
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -marm -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
export CXXFLAGS="${COMMONFLAGS} -fvisibility=hidden -fvisibility-inlines-hidden"
echo "Building armv7s..."
make clean
./configure --cpu=cortex-a9 --extra-cflags=‘-I$X264INCLUDE -I$FAACINCLUDE -arch armv7s -miphoneos-version-min=5.0 -mthumb‘ --extra-ldflags=‘-L$X264LIB -L$FAACLIB -arch armv7s -miphoneos-version-min=5.0‘ --enable-cross-compile --arch=arm --disable-iconv --target-os=darwin --cc=${CC} --disable-asm --sysroot=${SDKROOT} --prefix=../${INSTALL}/armv7s --enable-gpl --enable-nonfree --enable-version3 --disable-bzlib --enable-small --disable-vda --disable-encoders --enable-libx264 --enable-libfaac --enable-encoder=libx264 --enable-encoder=libfaac --disable-muxers --enable-muxer=flv --enable-muxer=mov --enable-muxer=ipod --enable-muxer=mpegts --enable-muxer=psp --enable-muxer=mp4 --enable-muxer=avi --disable-decoders --enable-decoder=aac --enable-decoder=aac_latm --enable-decoder=h264 --enable-decoder=mpeg4 --disable-demuxers --enable-demuxer=flv --enable-demuxer=h264 --enable-demuxer=avi --enable-demuxer=mpegts --enable-demuxer=mpc --enable-demuxer=mov --disable-parsers --enable-parser=aac --enable-parser=ac3 --enable-parser=h264 --disable-protocols --enable-protocol=file --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=udp --disable-bsfs --enable-bsf=aac_adtstoasc --enable-bsf=h264_mp4toannexb --disable-devices --disable-debug --disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-ffserver --disable-debug
make
make install
cd ..
(5) 编译arm64版本FFmpeg类库
这一步用于生成支持arm64架构的thin版本的FFmpeg类库，存储于thin-ffmpeg/arm64文件夹中。脚本如下所示。
build_ffmpeg_demo_arm64.sh
#!/bin/sh
# LXH,MXY modified
cd ffmpeg
PLATFORM="iPhoneOS"
INSTALL="thin-ffmpeg"
SDK_VERSION="8.3"
# libx264
export X264ROOT=../thin-x264/arm64
export X264LIB=$X264ROOT/lib
export X264INCLUDE=$X264ROOT/include
# libfaac
export FAACROOT=../thin-faac/arm64
export FAACLIB=$FAACROOT/lib
export FAACINCLUDE=$FAACROOT/include
export DEVROOT=/Applications/Xcode.app/Contents/Developer
export SDKROOT=$DEVROOT/Platforms/${PLATFORM}.platform/Developer/SDKs/${PLATFORM}${SDK_VERSION}.sdk
export CC=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
export AS=$DEVROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/as
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -marm -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
export CXXFLAGS="${COMMONFLAGS} -fvisibility=hidden -fvisibility-inlines-hidden"
echo "Building arm64..."
make clean
./configure --extra-cflags=‘-I$X264INCLUDE -I$FAACINCLUDE -arch arm64 -miphoneos-version-min=5.0 -mthumb‘ --extra-ldflags=‘-L$X264LIB -L$FAACLIB -arch arm64 -miphoneos-version-min=5.0‘ --enable-cross-compile --arch=arm --disable-iconv --target-os=darwin --cc=${CC} --disable-asm --sysroot=${SDKROOT} --prefix=../${INSTALL}/arm64 --enable-gpl --enable-nonfree --enable-version3 --disable-bzlib --enable-small --disable-vda --disable-encoders --enable-libx264 --enable-libfaac --enable-encoder=libx264 --enable-encoder=libfaac --disable-muxers --enable-muxer=flv --enable-muxer=mov --enable-muxer=ipod --enable-muxer=mpegts --enable-muxer=psp --enable-muxer=mp4 --enable-muxer=avi --disable-decoders --enable-decoder=aac --enable-decoder=aac_latm --enable-decoder=h264 --enable-decoder=mpeg4 --disable-demuxers --enable-demuxer=flv --enable-demuxer=h264 --enable-demuxer=avi --enable-demuxer=mpegts --enable-demuxer=mpc --enable-demuxer=mov --disable-parsers --enable-parser=aac --enable-parser=ac3 --enable-parser=h264 --disable-protocols --enable-protocol=file --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=udp --disable-bsfs --enable-bsf=aac_adtstoasc --enable-bsf=h264_mp4toannexb --disable-devices --disable-debug --disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-ffserver --disable-debug
make
make install
cd ..
(6) 编译i386版本FFmpeg类库
这一步用于生成支持i386架构的thin版本的FFmpeg类库，存储于thin-ffmpeg/i386文件夹中。脚本如下所示。
build_ffmpeg_demo_i386.sh
#!/bin/sh
# LXH,MXY modified
cd ffmpeg
PLATFORM="iPhoneSimulator"
INSTALL="thin-ffmpeg"
SDK_VERSION="8.3"
# libx264
export X264ROOT=../thin-x264/i386
export X264LIB=$X264ROOT/lib
export X264INCLUDE=$X264ROOT/include
# libfaac
export FAACROOT=../thin-faac/i386
export FAACLIB=$FAACROOT/lib
export FAACINCLUDE=$FAACROOT/include
export DEVROOT=/Applications/Xcode.app/Contents/Developer/Platforms/${PLATFORM}.platform/Developer
export SDKROOT=$DEVROOT/SDKs/${PLATFORM}${SDK_VERSION}.sdk
export CC=$DEVROOT/usr/bin/gcc
export LD=$DEVROOT/usr/bin/ld
export CXX=$DEVROOT/usr/bin/g++
export LIBTOOL=$DEVROOT/usr/bin/libtool
COMMONFLAGS="-pipe -gdwarf-2 -no-cpp-precomp -isysroot ${SDKROOT} -fPIC"
export LDFLAGS="${COMMONFLAGS} -fPIC"
export CFLAGS="${COMMONFLAGS} -fvisibility=hidden"
echo "Building i386..."
make clean
./configure --cpu=i386 --extra-cflags=‘-I$X264INCLUDE -I$FAACINCLUDE -arch i386 -miphoneos-version-min=5.0‘ --extra-ldflags=‘-L$X264LIB -L$FAACLIB -arch i386 -miphoneos-version-min=5.0‘ --enable-cross-compile --arch=i386 --disable-iconv --target-os=darwin --cc=${CC} --sysroot=${SDKROOT} --prefix=../${INSTALL}/i386 --enable-gpl --enable-nonfree --enable-version3 --disable-bzlib --enable-small --disable-vda --disable-encoders --enable-libx264 --enable-libfaac --enable-encoder=libx264 --enable-encoder=libfaac --disable-muxers --enable-muxer=flv --enable-muxer=mov --enable-muxer=mpegts --enable-muxer=ipod --enable-muxer=psp --enable-muxer=mp4 --enable-muxer=avi --disable-decoders --enable-decoder=aac --enable-decoder=aac_latm --enable-decoder=h264 --enable-decoder=mpeg4 --disable-demuxers --enable-demuxer=flv --enable-demuxer=h264 --enable-demuxer=mpegts --enable-demuxer=avi --enable-demuxer=mpc --enable-demuxer=mov --disable-parsers --enable-parser=aac --enable-parser=ac3 --enable-parser=h264 --disable-protocols --enable-protocol=file --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=udp --disable-bsfs --enable-bsf=aac_adtstoasc --enable-bsf=h264_mp4toannexb --disable-devices --disable-debug --disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-ffserver --disable-debug
make
make install
cd ..
(7) 编译x86_64版本FFmpeg类库
这一步用于生成支持x86_64架构的thin版本的FFmpeg类库，存储于thin-ffmpeg/x86_64文件夹中。脚本如下所示。
build_ffmpeg_demo_x86_64.sh
#!/bin/sh
# LXH,MXY modified
cd ./ffmpeg
INSTALL="thin-ffmpeg"
# libx264
export X264ROOT=../thin-x264/x86_64
export X264LIB=$X264ROOT/lib
export X264INCLUDE=$X264ROOT/include
# libfaac
export FAACROOT=../thin-faac/x86_64
export FAACLIB=$FAACROOT/lib
export FAACINCLUDE=$FAACROOT/include
unset DEVROOT
unset SDKROOT
unset CC
unset LD
unset CXX
unset LIBTOOL
unset HOST
unset LDFLAGS
unset CFLAGS
echo "Building x86_64..."
make clean
./configure --extra-cflags=‘-I$X264INCLUDE -I$FAACINCLUDE‘ --extra-ldflags=‘-L$X264LIB -L$FAACLIB‘ --disable-iconv --disable-asm --prefix=../${INSTALL}/x86_64 --enable-gpl --enable-nonfree --enable-version3 --disable-bzlib --enable-small --disable-vda --disable-encoders --enable-libx264 --enable-libfaac --enable-encoder=libx264 --enable-encoder=mpeg2video --enable-encoder=libfaac --disable-muxers --enable-muxer=flv --enable-muxer=mov --enable-muxer=ipod --enable-muxer=mpegts --enable-muxer=psp --enable-muxer=mp4 --enable-muxer=avi --disable-decoders --enable-decoder=aac --enable-decoder=mpeg2video --enable-decoder=aac_latm --enable-decoder=h264 --enable-decoder=mpeg4 --disable-demuxers --enable-demuxer=flv --enable-demuxer=h264 --enable-demuxer=avi --enable-demuxer=mpegts --enable-demuxer=mpc --enable-demuxer=mov --disable-parsers --enable-parser=aac --enable-parser=ac3 --enable-parser=h264 --disable-protocols --enable-protocol=file --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=udp --enable-bsf=aac_adtstoasc --enable-bsf=h264_mp4toannexb --disable-devices --disable-debug --disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-ffserver --disable-debug
make
make install
cd ..
(8) 打包类库
这一步用于将上述步骤中生成的5个版本的FFmpeg打包生成fat版本的FFmpeg类库。这一步骤执行完毕后，将thin-ffmpeg中几个thin版本的类库合并为一个fat版本的类库，并存储于fat-ffmpeg文件夹中。脚本如下所示。
build_ffmpeg_fat.sh
#!/bin/sh # directories THIN=`pwd`/"thin-ffmpeg" FAT=`pwd`/"fat-ffmpeg" CWD=`pwd` # must be an absolute path ARCHS="armv7s i386 armv7 arm64 x86_64" echo "building fat binaries..." mkdir -p $FAT/lib set - $ARCHS cd thin-ffmpeg/$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
生成完fat版本的类库后，可以在命令行使用lipo命令查看类库的架构，如下所示。
lipo -info libavcodec.a
2. 编写IOS程序
编写包含FFmpeg类库支持的IOS程序分成两步：配置Xcode环境，编写C语言代码。
(1) 配置Xcode环境
下面以Xcode的IOS中的Single View Application为例，记录一下配置步骤：
(a) 拷贝头文件所在的include文件夹和fat版本的FFmpeg类库（包括libavformat.a， libavcodec.a， libavutil.a， libavdevice.a， libavfilter.a， libpostproc.a， libswresample.a， libswscale.a；以及第三方fat版本类库libx264.a， libfaac.a）至项目文件夹。并将它们添加至项目中。
(b) 项目属性->Build Settings中配置以下3个选项。
Linking->Other Linker Flags中添加下面内容：
-lavformat -lavcodec -lavutil -lavdevice -lavfilter -lpostproc -lswresample -lswscale -lx264 -lfaac
Search Paths->Header Search Paths添加下面内容
$(PROJECT_DIR)/include
Search Paths->Library Search Paths添加下面内容
$(PROJECT_DIR)
其它的一些配置。这些配置随着FFmpeg版本的不同而有略微的不同（在某些情况下也可能不需要配置）。我目前使用的2.7.1版本的FFmpeg需要配置下面的选项。
项目属性->General->Linked Frameworks and Libraries中添加两个类库：AVFoundation.framework和libz.dylib。
(2) 编写C语言代码
做好上面配置后，就可以在项目中编写代码测试一下FFmpeg是否正确配置了。由于IOS使用的Objective-C是兼容C语言的，所以可以直接写C语言代码调用FFmpeg。可以在ViewController.m中的viewDidLoad()函数中添加一行printf()代码打印FFmpeg类库的版本信息，如下所示。
#import "ViewController.h"
#include <libavcodec/avcodec.h>
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
printf("%s",avcodec_configuration());
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
如果类库编译无误，启动IOS程序的时候会在控制台打印版本信息。
源代码
项目的目录结构如图所示。
C代码位于ViewController.m文件中，内容如下所示。
/**
* 最简单的基于FFmpeg的HelloWorld程序 － IOS
* Simplest FFmpeg Helloworld － IOS
*
* 雷霄骅 Lei Xiaohua
* [email protected]
* 中国传媒大学/数字电视技术
* Communication University of China / Digital TV Technology
* http://blog.csdn.net/leixiaohua1020
*
* 本程序可以获得FFmpeg类库相关的信息。
* This software can get information about FFmpeg libraries.
*
*/
#import "ViewController.h"
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfilter.h>
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
av_register_all();
char info[10000] = { 0 };
printf("%s\n", avcodec_configuration());
sprintf(info, "%s\n", avcodec_configuration());
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)clickProtocolButton:(id)sender {
//Alert
/*
UIAlertView *alter = [[UIAlertView alloc] initWithTitle:@"Title" message:@"This is content" delegate:nil cancelButtonTitle:@"Close" otherButtonTitles:nil];
[alter show];
*/
char info[40000]={0};
av_register_all();
struct URLProtocol *pup = NULL;
//Input
struct URLProtocol **p_temp = &pup;
avio_enum_protocols((void **)p_temp, 0);
while ((*p_temp) != NULL){
sprintf(info, "%s[In ][%10s]\n", info, avio_enum_protocols((void **)p_temp, 0));
}
pup = NULL;
//Output
avio_enum_protocols((void **)p_temp, 1);
while ((*p_temp) != NULL){
sprintf(info, "%s[Out][%10s]\n", info, avio_enum_protocols((void **)p_temp, 1));
}
//printf("%s", info);
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
- (IBAction)clickAVFormatButton:(id)sender {
char info[40000] = { 0 };
av_register_all();
AVInputFormat *if_temp = av_iformat_next(NULL);
AVOutputFormat *of_temp = av_oformat_next(NULL);
//Input
while(if_temp!=NULL){
sprintf(info, "%s[In ]%10s\n", info, if_temp->name);
if_temp=if_temp->next;
}
//Output
while (of_temp != NULL){
sprintf(info, "%s[Out]%10s\n", info, of_temp->name);
of_temp = of_temp->next;
}
//printf("%s", info);
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
- (IBAction)clickAVCodecButton:(id)sender {
char info[40000] = { 0 };
av_register_all();
AVCodec *c_temp = av_codec_next(NULL);
while(c_temp!=NULL){
if (c_temp->decode!=NULL){
sprintf(info, "%s[Dec]", info);
}
else{
sprintf(info, "%s[Enc]", info);
}
switch (c_temp->type){
case AVMEDIA_TYPE_VIDEO:
sprintf(info, "%s[Video]", info);
break;
case AVMEDIA_TYPE_AUDIO:
sprintf(info, "%s[Audio]", info);
break;
default:
sprintf(info, "%s[Other]", info);
break;
}
sprintf(info, "%s%10s\n", info, c_temp->name);
c_temp=c_temp->next;
}
//printf("%s", info);
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
- (IBAction)clickAVFilterButton:(id)sender {
char info[40000] = { 0 };
av_register_all();
AVFilter *f_temp = (AVFilter *)avfilter_next(NULL);
while (f_temp != NULL){
sprintf(info, "%s[%10s]\n", info, f_temp->name);
}
//printf("%s", info);
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
- (IBAction)clickConfigurationButton:(id)sender {
char info[10000] = { 0 };
av_register_all();
sprintf(info, "%s\n", avcodec_configuration());
//printf("%s", info);
//[email protected]"Lei Xiaohua";
NSString * info_ns = [NSString stringWithFormat:@"%s", info];
self.content.text=info_ns;
}
@end
运行结果
App在手机上运行后的结果如下图所示。
单击不同的按钮，可以得到类库不同方面的信息。单击“Protocol”按钮内容如下所示。
单击“AVFormat”按钮内容如下所示。
单击“AVCodec”按钮内容如下所示。
单击“Configure”按钮即为程序开始运行时候的内容。
下载
simplest ffmpeg mobile
项目主页
Github：https://github.com/leixiaohua1020/simplest_ffmpeg_mobile
开源中国：https://git.oschina.net/leixiaohua1020/simplest_ffmpeg_mobile
CSDN工程下载地址：http://download.csdn.net/detail/leixiaohua1020/8924391
本解决方案包含了使用FFmpeg在移动端处理多媒体的各种例子：
[Android]
simplest_android_player: 基于安卓接口的视频播放器
simplest_ffmpeg_android_helloworld: 安卓平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_android_decoder: 安卓平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_android_decoder_onelib: 安卓平台下最简单的基于FFmpeg的视频解码器-单库版
simplest_ffmpeg_android_streamer: 安卓平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_android_transcoder: 安卓平台下移植的FFmpeg命令行工具
simplest_sdl_android_helloworld: 移植SDL到安卓平台的最简单程序
[IOS]
simplest_ios_player: 基于IOS接口的视频播放器
simplest_ffmpeg_ios_helloworld: IOS平台下基于FFmpeg的HelloWorld程序
simplest_ffmpeg_ios_decoder: IOS平台下最简单的基于FFmpeg的视频解码器
simplest_ffmpeg_ios_streamer: IOS平台下最简单的基于FFmpeg的推流器
simplest_ffmpeg_ios_transcoder: IOS平台下移植的ffmpeg.c命令行工具
simplest_sdl_ios_helloworld: 移植SDL到IOS平台的最简单程序
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时间： 2024-10-29 19:08:08