1. 编译ffmpeg.
   1. 下载源码后可以自己手动编译 ,反正是通过各种命令 配置configure 
   2. 通过一个很牛逼的脚本:git@github.com:kewlbear/FFmpeg-iOS-build-script.git     下载之后,检查ffmpeg的版本号,替换成最新的 然后运行脚本就行了
      1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155

      #!/bin/sh   # directories SOURCE= "ffmpeg-2.6.1" 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="$CONFIGURE_FLAGS --enable-avresample"   ARCHS= "arm64 armv7s armv7 x86_64 i386"   COMPILE= "y" LIPO= "y"   DEPLOYMENT_TARGET= "6.0"   if  [  "$*"  ] 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 )"  \                  ||  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
2. 导入项目,有静态包经验的就就不用看了,这个对于我这个半路出家的和尚还是处理了老半天才解决.
   .a文件直接导入 .h文件要导入文件夹结构   配置header search 环境变量  使用的时候导入文件 结构:#import "文件夹/文件.h"
3. 编译.
   1. 首次编译.
      Undefined symbols for architecture armv7:  "_deflateInit2_", referenced from:      _encode_frame in libavcodec.a(pngenc.o)  "_crc32", referenced from:      _encode_frame in libavcodec.a(pngenc.o)  "_deflateReset", referenced from:      _encode_frame in libavcodec.a(lclenc.o)      _encode_frame in libavcodec.a(zmbvenc.o)  "_compress", referenced from:      _encode_strip in libavcodec.a(tiffenc.o)  "_deflateBound", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)      _encode_frame in libavcodec.a(pngenc.o)      _encode_frame in libavcodec.a(lclenc.o)  "_inflateSync", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)  "_inflateReset", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)      _zlib_decomp in libavcodec.a(lcldec.o)      _decode_frame in libavcodec.a(tscc.o)      _zerocodec_decode_frame in libavcodec.a(zerocodec.o)      _decode_frame in libavcodec.a(zmbv.o)  "_iconv_open", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_BZ2_bzDecompress", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_inflate", referenced from:      _http_read_stream in libavformat.a(http.o)      _matroska_decode_buffer in libavformat.a(matroskadec.o)      _rtmp_open in libavformat.a(rtmpproto.o)      _zlib_refill in libavformat.a(swfdec.o)      _decode_frame_common in libavcodec.a(pngdec.o)      _decode_text_chunk in libavcodec.a(pngdec.o)      _flashsv_decode_frame in libavcodec.a(flashsv.o)      ...  "_inflateInit_", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)      _rtmp_open in libavformat.a(rtmpproto.o)      _swf_read_header in libavformat.a(swfdec.o)      _decode_frame_apng in libavcodec.a(pngdec.o)      _decode_frame_png in libavcodec.a(pngdec.o)      _decode_text_chunk in libavcodec.a(pngdec.o)      _flashsv_decode_init in libavcodec.a(flashsv.o)      ...  "_iconv", referenced from:      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_BZ2_bzDecompressEnd", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_inflateInit2_", referenced from:      _http_read_header in libavformat.a(http.o)  "_deflateEnd", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)      _flashsv2_encode_frame in libavcodec.a(flashsv2enc.o)      _flashsv_encode_init in libavcodec.a(flashsvenc.o)      _flashsv_encode_end in libavcodec.a(flashsvenc.o)      _encode_frame in libavcodec.a(pngenc.o)      _encode_end in libavcodec.a(lclenc.o)      _encode_init in libavcodec.a(zmbvenc.o)      ...  "_BZ2_bzDecompressInit", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_deflateInit_", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)      _flashsv2_encode_frame in libavcodec.a(flashsv2enc.o)      _encode_init in libavcodec.a(lclenc.o)      _encode_init in libavcodec.a(zmbvenc.o)  "_zlibCompileFlags", referenced from:      _http_read_header in libavformat.a(http.o)  "_compress2", referenced from:      _flashsv2_encode_frame in libavcodec.a(flashsv2enc.o)      _flashsv_encode_frame in libavcodec.a(flashsvenc.o)  "_deflate", referenced from:      _flashsv_decode_frame in libavcodec.a(flashsv.o)      _flashsv2_encode_frame in libavcodec.a(flashsv2enc.o)      _encode_frame in libavcodec.a(pngenc.o)      _encode_frame in libavcodec.a(lclenc.o)      _encode_frame in libavcodec.a(zmbvenc.o)  "_inflateEnd", referenced from:      _http_close in libavformat.a(http.o)      _http_read_header in libavformat.a(http.o)      _matroska_decode_buffer in libavformat.a(matroskadec.o)      _rtmp_open in libavformat.a(rtmpproto.o)      _swf_read_close in libavformat.a(swfdec.o)      _decode_frame_apng in libavcodec.a(pngdec.o)      _decode_frame_png in libavcodec.a(pngdec.o)      ...  "_uncompress", referenced from:      _id3v2_read_internal in libavformat.a(id3v2.o)      _mov_read_cmov in libavformat.a(mov.o)      _swf_read_packet in libavformat.a(swfdec.o)      _decode_frame in libavcodec.a(cscd.o)      _decode_frame in libavcodec.a(dxa.o)      _decode_block in libavcodec.a(exr.o)      _g2m_decode_frame in libavcodec.a(g2meet.o)      ...  "_iconv_close", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)ld: symbol(s) not found for architecture armv7clang: error: linker command failed with exit code 1 (use -v to see invocation)

      导入 libz.1.2.5.dylib ,再次编译

      Undefined symbols for architecture armv7:  "_BZ2_bzDecompressInit", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_iconv", referenced from:      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_BZ2_bzDecompress", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_BZ2_bzDecompressEnd", referenced from:      _matroska_decode_buffer in libavformat.a(matroskadec.o)  "_iconv_open", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_iconv_close", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)ld: symbol(s) not found for architecture armv7clang: error: linker command failed with exit code 1 (use -v to see invocation)

      导入 libbz2.1.0.dylib ,再次编译

      Undefined symbols for architecture armv7:  "_iconv", referenced from:      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_iconv_open", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)  "_iconv_close", referenced from:      _avcodec_open2 in libavcodec.a(utils.o)      _avcodec_decode_subtitle2 in libavcodec.a(utils.o)ld: symbol(s) not found for architecture armv7clang: error: linker command failed with exit code 1 (use -v to see invocation)

      导入  libiconv.2.4.0.dylib  编译通过