Question

我一直在努力以我能想到的每一种可能的方式构建ffmpeg。我正在尝试使用他们的git存储库中的最新版本，并使用构建脚本我确认它有效，它来自这个问题：iPhone SDK 4.3 libav compiling problem。该脚本昨天更新，显然适用于问题中的人。

我的问题是它不会为armv6和armv7生成.a文件（或实际上是任何文件）。因此， lipo 命令，连接到通用库，失败。我也尝试过使用iFrameExtractor中的构建脚本而没有任何成功，最后还是使用了lipo-commands失败了，我得到以下内容：

lipo: can't open input file: ./compiled/armv6/lib/libavcodec.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libavdevice.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libavfilter.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libavformat.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libavutil.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libpostproc.a (No such file or directory)
lipo: can't open input file: ./compiled/armv6/lib/libswscale.a (No such file or directory)

并且我还发布了整个输出here，如果有人知道在那里寻找什么（因为我不知道从哪里开始，它几乎有5000行输出。）我还应该提一下，我正在为 armv6 ， armv7 和 i386 编译它。我想在XCode中导入它以从视频输入中获取H.264帧。

当我尝试为armv6构建时，我使用以下配置：

./configure \
--enable-cross-compile \
--arch=arm \
--extra-cflags='-arch armv6' \
--extra-ldflags='-arch armv6' \
--target-os=darwin \
--cc=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc \
--sysroot=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk \
--cpu=arm1176jzf-s \
--extra-ldflags=-L/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneSimulator4.3.sdk/usr/lib/system \
--prefix=compiled/armv6

并获得以下输出：

/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc is unable to create an executable file.
C compiler test failed.

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "config.log" produced by configure as this will help
solving the problem.

所以问题，我应该使用什么c编译器？我尝试过不同的：臂苹果darwin10-GCC-4.2.1 臂苹果darwin10-LLVM-GCC-4.2 GCC

但结果相同。 gcc适用于i386和armv7，所以我想它应该适用于armv6以及

Answer 1

我使用以下内容仅编译armv6和armv7。我无法让它适用于i386，我收到的错误是cputype和subputype是错误的。显然cputype应该是x86，subputype应该是intel。

无论如何我使用以下构建脚本进行编译（我最终使用gcc并且它起作用，这是配置标志，从一开始我猜错了）用于arm架构：

构建脚本：

#!/bin/sh

set -e

SCRIPT_DIR=$( (cd -P $(dirname $0) && pwd) )
DIST_DIR_BASE=${DIST_DIR_BASE:="$SCRIPT_DIR/dist"}

if [ -d ffmpeg ]
then
  echo "Found ffmpeg source directory, no need to fetch from git..."
else
  echo "Fetching ffmpeg from git://git.videolan.org/ffmpeg.git..."
  git clone git://git.videolan.org/ffmpeg.git
fi

ARCHS=${ARCHS:-"armv6 armv7"}

for ARCH in $ARCHS
do
    FFMPEG_DIR=ffmpeg-$ARCH
    if [ -d $FFMPEG_DIR ]
    then
      echo "Removing old directory $FFMPEG_DIR"
      rm -rf $FFMPEG_DIR
    fi
    echo "Copying source for $ARCH to directory $FFMPEG_DIR"
    cp -a ffmpeg $FFMPEG_DIR

    cd $FFMPEG_DIR

    DIST_DIR=$DIST_DIR_BASE-$ARCH
    mkdir -p $DIST_DIR

    case $ARCH in
        armv6)
            EXTRA_FLAGS="--enable-cross-compile --target-os=darwin --arch=arm --cpu=arm1176jzf-s"
            EXTRA_CFLAGS="-arch $ARCH"
            EXTRA_LDFLAGS="-arch $ARCH"
            ;;
        armv7)
            EXTRA_FLAGS="--enable-cross-compile --target-os=darwin --arch=arm --cpu=cortex-a8 --enable-pic"
            EXTRA_CFLAGS="-arch $ARCH"
            EXTRA_LDFLAGS="-arch $ARCH"
            ;;
        x86_64)
            EXTRA_CC_FLAGS="-mdynamic-no-pic"
            ;;
    esac

    echo "Configuring ffmpeg for $ARCH..."
    ./configure \
    --prefix=$DIST_DIR \
    --extra-ldflags=-L/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk/usr/lib/system \
    --disable-bzlib \
    --disable-doc \
    --disable-ffmpeg \
    --disable-ffplay \
    --disable-ffserver \
    --cc=/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc \
    --sysroot=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk \
    --extra-ldflags="$EXTRA_LDFLAGS" \
    --extra-cflags="$EXTRA_CFLAGS" \
    $EXTRA_FLAGS

    echo "Installing ffmpeg for $ARCH..."
    make && make install

    cd $SCRIPT_DIR

    if [ -d $DIST_DIR/bin ]
    then
      rm -rf $DIST_DIR/bin
    fi
    if [ -d $DIST_DIR/share ]
    then
      rm -rf $DIST_DIR/share
    fi
done

并组合libs脚本：

#!/bin/bash

set -e

ARCHS="armv6 armv7"

for ARCH in $ARCHS
do
  if [ -d dist-$ARCH ]
  then
    MAIN_ARCH=$ARCH
  fi
done

if [ -z "$MAIN_ARCH" ]
then
  echo "Please compile an architecture"
  exit 1
fi


OUTPUT_DIR="dist-uarch"
rm -rf $OUTPUT_DIR

mkdir -p $OUTPUT_DIR/lib $OUTPUT_DIR/include

for LIB in dist-$MAIN_ARCH/lib/*.a
do
  LIB=`basename $LIB`
  LIPO_CREATE=""
  for ARCH in $ARCHS
  do
    if [ -d dist-$ARCH ]
    then
      LIPO_CREATE="$LIPO_CREATE-arch $ARCH dist-$ARCH/lib/$LIB "
    fi
  done
  OUTPUT="$OUTPUT_DIR/lib/$LIB"
  echo "Creating: $OUTPUT"
  lipo -create $LIPO_CREATE -output $OUTPUT
  lipo -info $OUTPUT
done

echo "Copying headers from dist-$MAIN_ARCH..."
cp -R dist-$MAIN_ARCH/include/* $OUTPUT_DIR/include

然后我从BUILD-FOLDER / dist-uarch导入.a文件，它就像魅力一样在xcode中构建！

无法为armv6-7构建ffmpeg

1 个答案: