最近刚接触ffmpeg,找了很多相关的编译资料，都没有编译成功，前几天在 github上找到一个脚本:

https://github.com/kewlbear/FFmpeg-iOS-build-script

准备条件：

1、先下载文件：

https://github.com/libav/gas-preprocessor

2、复制gas-preprocessor.pl到/usr/sbin下，修改文件权限：chmod 777 /usr/local/bin/gas-preprocessor.pl

3、安装yasm

具体步骤如下：

1. 下载脚本：https://github.com/kewlbear/FFmpeg-iOS-build-script
2. 解压，找到文件 build-ffmpeg.sh
3. 执行服本文件：./build-ffmpeg.sh, 由于本人没有事先安装Yasm　执行脚本文件会出错，
   如下：

MAC:FFmpeg-iOS-build-script-master-2 jinsonglnan$ ./build-ffmpeg.sh 

Yasm not found

Homebrew not found. Trying to install...

Whoops, the Homebrew installer has moved! Please instead run:

ruby -e 
"$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Also, please ask wherever you got 
this
 link from to update it to the above.

Trying to install Yasm...

./build-ffmpeg.sh: line 67: brew: command not found

MAC:FFmpeg-iOS-build-script-master-2 jinsonglnan$ ./build-ffmpeg.sh 

Yasm not found

Homebrew not found. Trying to install...

Whoops, the Homebrew installer has moved! Please instead run:

ruby -e 
"$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Also, please ask wherever you got 
this
 link from to update it to the above.

Trying to install Yasm...

./build-ffmpeg.sh: line 67: brew: command not found

意思就是说，没有yasm, 看到提示执行:

 ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

安装

4.编译完成后，终端进入FFmpeg-iOS-build-script目录，然后输入./build-ffmpeg.sh lipo，这个命令是讲.a文件合并成一个
5.把ffmpeg-iOS文件加入到工程中
6.添加一个头文件引用 #include "avformat.h"
添加一个api语句：av_register_all();给一个类文件.m后缀改为.mm，开启混编模式。
运行工程，如果没有报错，则表明编译成功
7.其他注意细节
编译的时候报错： 'libavcodec/avcodec.h' file not found ，修改Header search paths 里的路径：$(PROJECT_DIR)/FFmpeg-iOS/include
加入External libraries：
libz.dylib
libbz2.dylib
libiconv.dylib
libz.dylib
libbz2.dylib
libiconv.dylib

8.编译好，写了个demo：点此下载

原文地址：http://www.cocoachina.com/ios/20150514/11827.html