ios - 在 iOS 中使用位码模式编译 FFMPEG

Question

我编译了支持 iOS 7 和 8 的 FFMPEG 库，但自从最近发布的 iOS 9 发布了一个新功能，称为位码模式，作为默认设置，此设置已设置为 NO。

但如果我将其设置为是，将执行以下错误，

libavdevice.a(avfoundation.o)' 不包含位码。您必须在启用位码的情况下重建它(Xcode 设置 ENABLE_BITCODE)，从供应商处获取更新的库，或禁用此目标的位码。用于架构 arm64

有什么方法可以在启用位码的模式下编译支持 FFMpeg 的 FFMPEG

这是我使用的构建脚本

#!/bin/sh

# directories
SOURCE="ffmpeg-2.6.2"
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/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.github.com/Homebrew/homebrew/go/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=$DEPLOYMENT_TARGET"
            if [ "$ARCH" = "arm64" ]
            then
                EXPORT="GASPP_FIX_XCODE5=1"
            fi
        fi

        XCRUN_SDK=`echo $PLATFORM | tr '[:upper:]' '[:lower:]'`
        CC="xcrun -sdk $XCRUN_SDK clang"
        CXXFLAGS="$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" \
            $CONFIGURE_FLAGS \
            --extra-cflags="$CFLAGS" \
            --extra-cxxflags="$CXXFLAGS" \
            --extra-ldflags="$LDFLAGS" \
            --prefix="$THIN/$ARCH" \
        || 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

Answer 1

我使用以下 CONFIGURE_FLAGS 让它工作:

CONFIGURE_FLAGS="--enable-cross-compile --disable-debug --disable-programs \
                 --disable-doc --enable-pic \
                 --extra-cflags=-fembed-bitcode --extra-cxxflags=-fembed-bitcode"

如果您只需要解码视频，则应添加更多标志以禁用所有复用器、编码器。您可能也不需要过滤器。这将节省一些空间。我还禁用了 iOS 模拟器不需要的 ARCH i386。

我将这些标志用于我的项目:

CONFIGURE_FLAGS="--enable-cross-compile --disable-debug --disable-programs \
                 --disable-doc --enable-pic \
                 --extra-cflags=-fembed-bitcode --extra-cxxflags=-fembed-bitcode \
                 --enable-nonfree --enable-gpl \
                 --disable-ffserver --disable-ffmpeg   --disable-ffprobe \
                 --disable-avdevice --disable-avfilter --disable-encoders \
                 --disable-parsers  --disable-decoders --disable-protocols \
                 --disable-filters  --disable-muxers   --disable-bsfs \
                 --disable-indevs   --disable-outdevs  --disable-demuxers \
                 --enable-protocol=file \
                 --enable-protocol=tcp \
                 --enable-protocol=udp \
                 --enable-decoder=msmpeg4v3 \
                 --enable-decoder=mpeg4 \
                 --enable-decoder=mjpeg \
                 --enable-decoder=h264 \
                 --enable-parser=mpeg4video \
                 --enable-parser=mjpeg \
                 --enable-parser=h263 \
                 --enable-parser=h264 \
                 --enable-parser=aac \
                 --enable-demuxer=avi \
                 --enable-demuxer=mov \
                 --enable-demuxer=rtsp \
                 "