armv6 6-7的失败构建ffmpeg

Question

我一直在努力用我能想到的每一种可能的方法来建立框架。我正在尝试从他们的git存储库中获得最新的修订版，并使用一个构建脚本(我已经确认了它的工作能力)，它来自于这个问题：iPhone SDK4.3libav编译问题。剧本昨天更新了，显然对问题中的那个人有用。

我的问题是，它不会为.a anc armv7生成armv6文件(或实际上任何文件)。因此，要将lipo命令连接到通用库中，就会失败。我也尝试过使用来自iFrameExtractor的构建脚本，但没有成功--它也失败了--最后，我得到了以下命令：

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)

我还发布了整个输出这里，如果有人知道在那里查找什么(因为我不知道从哪里开始，它几乎有5000行输出)。我还应该提到，我正在为armv6、armv7和i386编译它。我想在XCode中导入它，以便从视频提要中获取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.

那么问题是，我应该使用什么c编译器呢？我尝试过不同的方法:手臂-苹果-杜温10- gcc -4.2.1手臂-苹果-达温10-11岁-gcc-4.2岁

但结果是一样的。gcc为i386和armv7工作，所以我想它也适用于armv6。

Answer 1

我使用以下方法只为armv6和armv7编译。我无法让它为i386工作，我收到的错误是cputype和subcputype是错误的。显然，cputype应该是x86，subcputype应该是intel。

无论如何，我使用以下构建脚本来编译arm体系结构(我最后使用了gcc，它工作了，从一开始就错误的是配置标志)：

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

并结合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-文件夹/Dist-uarch中导入.a文件，它以xcode构建，就像一个魅力！