编译iOS和gas预处理器.gas的ffmpeg

Question

我想为iOS编译ffmpeg。我以前做过几次。但现在我在全新的小牛和配置上，我总是得到

Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
GNU assembler not found, install gas-preprocessor

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.

我已经安装了当前的Xcode。还有啤酒。以及当前gas-preprocessor.pl (https://github.com/yuvi/gas-preprocessor)在usr/bin和usr/local/bin中的应用。

在perl /usr/bin/gas-preprocessor.pl gcc上我得到了Unrecognized input filetype at /usr/bin/gas-preprocessor.pl line 33.

此配置工作如下：

./configure \
--extra-cflags='-arch arm64 -mios-version-min=7.0 -mthumb' \
--extra-ldflags='-arch arm64 -mios-version-min=7.0' \
--enable-cross-compile \
--arch=arm64 \
--target-os=darwin \
--cc=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang \
--sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk \
--prefix=arm64 \
--disable-doc \
--disable-shared \
--disable-everything \
--enable-static \
--enable-pic \
--disable-muxers \
--enable-muxer=flv \
--disable-demuxers \
--enable-demuxer=h264 \
--enable-demuxer=pcm_s16le \
--disable-devices \
--disable-parsers \
--enable-parser=h264 \
--disable-encoders \
--enable-encoder=aac \
--disable-decoders \
--enable-decoder=h264 \
--enable-decoder=pcm_s16le \
--disable-protocols \
--enable-protocol=rtmp \
--disable-filters \
--disable-bsfs

此配置抛出以上错误(未找到GNU汇编程序，请安装gas预处理器)：

./configure \
--cpu=cortex-a8 \
--extra-cflags='-arch armv7 -mios-version-min=7.0 -mthumb' \
--extra-ldflags='-arch armv7 -mios-version-min=7.0' \
--enable-cross-compile \
--arch=armv7 \
--target-os=darwin \
--cc=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang \
--sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk \
--prefix=armv7 \
--disable-doc \
--disable-shared \
--disable-everything \
--enable-static \
--enable-pic \
--disable-muxers \
--enable-muxer=flv \
--disable-demuxers \
--enable-demuxer=h264 \
--enable-demuxer=pcm_s16le \
--disable-devices \
--disable-parsers \
--enable-parser=h264 \
--disable-encoders \
--enable-encoder=aac \
--disable-decoders \
--enable-decoder=h264 \
--enable-decoder=pcm_s16le \
--disable-protocols \
--enable-protocol=rtmp \
--disable-filters \
--disable-bsfs

Answer 1

是chmod +x gas-preprocessor.pl干的！

Answer 2

在ffmpeg编译：git://git.libav.org/gas-preprocessor.git时，必须使用gas-preprocessor.pl的特殊版本

来自yuvi (https://github.com/yuvi/gas-preprocessor)的版本已经过时(3年没有更改)，并且不适用于现代的ffmpeg版本

Answer 3

1. 从gas-preprocessor.pl下载https://github.com/mansr/gas-preprocessor
2. 将gas-preprocessor.pl复制到/usr/local/bin
3. 修改文件权限：chmod 777 /usr/local/bin/gas-preprocessor.pl