本文链接：https://www.jianshu.com/p/fe74a8579c34

源码地址：https://gitee.com/obarong/FFmpeg4iOS

目的：实现iOS的rtsp转mp4

方案：

~~ijkplayer：其实还是FFmpeg。~~
FFmpeg：之前做过安卓的rtsp转mp4，比较熟悉，所以用这个方案。

环境：

macOS 10.13.6
yasm 1.3.0
Xcode 10.1
FFmpeg 4.1
x264： x264-snapshot-20190325-2245-stable
Target Arch： armv7 arm64

1. FFmpeg

参考向晨宇的文章：

iOS编解码入门篇(FFMPEG环境搭建) | 向晨宇的技术博客
http://www.iosxxx.com/blog/2017-07-17-iOS%E7%BC%96%E8%A7%A3%E7%A0%81%E5%85%A5%E9%97%A8%E7%AF%87-FFMPEG%E7%8E%AF%E5%A2%83%E6%90%AD%E5%BB%BA.html

这里大概写一下关键步骤。

下载ffmpeg编译脚本：

kewlbear/FFmpeg-iOS-build-script: Shell scripts to build FFmpeg for iOS and tvOS
https://github.com/kewlbear/FFmpeg-iOS-build-script

执行编译脚本，自动按顺序下载安装homebrew、yasm、gas-preprocessor、ffmpeg源码

$ ./build-ffmpeg.sh armv7 arm64

合并a文件

$ ./build-ffmpeg.sh lipo

合并后的a文件在FFmpeg-iOS/lib目录下，头文件在FFmpeg-iOS/include目录。

2. x264

下载x264源码

Index of /pub/videolan/x264/snapshots/
http://download.videolan.org/pub/videolan/x264/snapshots/

下载x264编译脚本

kewlbear/x264-ios: Script to build x264 for iOS apps
https://github.com/kewlbear/x264-ios

执行编译脚本

$ ./build-x264.sh armv7 arm64

合并

$ ./build-x264.sh lipo

合并后的a文件和头文件在x264-iOS目录。

3. FFmpeg+x264

将x264-iOS放到ffmpeg编译脚本的目录，改名为fat-x264，反注释build-ffmpeg.sh这行

X264=`pwd`/fat-x264

再编一次ffmpeg。

4. 新建Xcode工程FFmpeg4iOS

复制FFmpeg-iOS和x264-iOS目录到FFmpeg4iOS/FFmpeg4iOS下。

复制scratch对应架构的config.h到FFmpeg4iOS/FFmpeg4iOS/FFmpeg-iOS/include/config下。

参考ijkplayer用一个config.h管理几个架构，新建文件FFmpeg4iOS/FFmpeg4iOS/FFmpeg-iOS/include/config/config.h

#if   defined(__aarch64__)
#   include "arm64/config.h"
#elif defined(__x86_64__)
#   include "x86_64/config.h"
#elif defined(__arm__)

#   if   defined(__ARM_ARCH_7S__)
#       include "armv7s/config.h"
#   elif defined(__ARM_ARCH)
#       if __ARM_ARCH == 7
#           include "armv7/config.h"
#       else
#           error Unsupport ARM architecture
#       endif
#   else
#       error Unsupport ARM architecture
#   endif

#elif defined(__i386__)
#   include "i386/config.h"
#else
#   error Unsupport architecture
#endif

设置Header Search Paths:

$(PROJECT_DIR)/FFmpeg4iOS/FFmpeg-iOS/include
$(PROJECT_DIR)/FFmpeg4iOS/x264-iOS/include

Library Search Paths:

$(PROJECT_DIR)/FFmpeg4iOS/FFmpeg-iOS/lib
$(PROJECT_DIR)/FFmpeg4iOS/x264-iOS/lib

项目配置linked frameworks and libraries加上VideoToolbox.framework libz.tbd libbz2.tbd libiconv.tbd CoreMedia.framework AudioToolBox.framework。

补全缺少的十几个头文件（？）

添加测试代码

    av_register_all();
    NSLog(@"version=%d\n", avcodec_version());

编译运行，打印log

version=3810148

集成ffmpeg成功。

5. RTSP转MP4

参考剑西的文章，虽然是安卓端，但方法都是通的。

编译Android下可执行命令的FFmpeg - 剑西 - CSDN博客
https://blog.csdn.net/mabeijianxi/article/details/72904694

复制fftools到工程的FFmpeg-iOS目录，不要ffplay、ffprobe、ffmpeg_qsv、Makefile。

目录结构

修改ffmpeg.c和ffmpeg.h的main函数，修改后是这样

int jrRun(int argc, char **argv)

修改cmdutils.c

int exit_program(int ret)
{
    if (program_exit)
        program_exit(ret);

//    exit(ret);
    return ret;
}

修改cmdutils.h

int exit_program(int ret);

在ffmpeg.c，jrRun的return前加上

    nb_filtergraphs = 0;
    progress_avio = NULL;
    
    input_streams = NULL;
    nb_input_streams = 0;
    input_files = NULL;
    nb_input_files = 0;
    
    output_streams = NULL;
    nb_output_streams = 0;
    output_files = NULL;
    nb_output_files = 0;

ffmpeg_opt.c的opt_init_hw_device函数最后面加上return 0;

打开文件共享

在 Info.plist 文件中添加 UIFileSharingEnabled 这个Key, 并设置该值为 YES 即可

把testfile.mpg复制到手机。

文件共享

测试代码

    //获取文件位置
    NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    
//    NSString *vidPath = @"rtsp://184.72.239.149/vod/mp4://BigBuckBunny_175k.mov";
    NSString *vidPath = [NSString stringWithFormat:@"%@/testfile.mpg", docPath];
    
    NSString *outPath = [NSString stringWithFormat:@"%@/h264.mp4", docPath];
    
    NSString *cmd=[NSString stringWithFormat:@"ffmpeg -y -i %@ -c:v libx264 %@", vidPath, outPath];
    NSArray *array = [cmd componentsSeparatedByString:@" "];
    NSLog(@"array:%@",array);
    
    int argc = [array count];
    char *argv[argc];
    for (int i = 0; i < argc; i++) {
        argv[i] = [[array objectAtIndex:i] UTF8String];
    }
    jrRun(argc, argv);

测试h264编码成功。音频自动转码成aac（LC），我没有集成fdk-aac，为什么可以转aac？

h264

测试RTSP转MP4成功

rtsp2mp4

（完）

附录

新建项目签名时，卡在signing，菊花转。。要打开双重验证苹果账号。
编译报错

$ ./build-x264.sh 
building arm64...
No working C compiler found.

$ ./build-ffmpeg.sh 
FFmpeg source not found. Trying to download...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 10.1M  100 10.1M    0     0   876k      0  0:00:11  0:00:11 --:--:--  933k
building arm64...
xcrun -sdk iphoneos clang 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
[email protected] mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "ffbuild/config.log" produced by configure as this will help
solve the problem.

看config.log

WARNING: pkg-config not found, library detection may fail.
mktemp -u XXXXXX
lGTJ1g
test_ld cc
test_cc
BEGIN /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test.c
    1   int main(void){ return 0; }
END /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test.c
xcrun -sdk iphoneos clang -arch arm64 -mios-version-min=8.0 -fembed-bitcode -c -o /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test.o /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test.c
xcrun: error: SDK "iphoneos" cannot be located
xcrun -sdk iphoneos clang -arch arm64 -mios-version-min=8.0 -fembed-bitcode -o /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test /var/folders/n4/3_0qsdm172v_6vr7gdnxz3zc0000gn/T/ffconf.9TYNjHRZ/test.o
xcrun: error: SDK "iphoneos" cannot be located
ld: warning: ignoring file /usr/lib/libSystem.dylib, missing required architecture arm64 in file /usr/lib/libSystem.dylib (2 slices)
ld: dynamic main executables must link with libSystem.dylib for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
C compiler test failed.

解：
参考这里解决
C compiler test failed. · Issue #130 · kewlbear/FFmpeg-iOS-build-script
https://github.com/kewlbear/FFmpeg-iOS-build-script/issues/130

关键是这句

$ sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer/

编译报错：

Undefined symbols for architecture arm64:
  "_VTDecompressionSessionDecodeFrame", referenced from:
      _videotoolbox_common_end_frame in libavcodec.a(videotoolbox.o)
      ...
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

解：
项目配置linked frameworks and libraries加上VideoToolbox.framework libz.tbd libbz2.tbd libiconv.tbd CoreMedia.framework AudioToolBox.framework

编译报错

The file “FFmpeg4iOS.app” couldn’t be opened because you don’t have permission to view it.

解：
不知道什么问题。clean一下就好了。

编译报错

Undefined symbols for architecture arm64:
  "_videotoolbox_pixfmt", referenced from:
      _options in ffmpeg_opt.o

解：
补上ffmpeg_videotoolbox.c

报错

Undefined symbols for architecture arm64:
  "_pp_get_context", referenced from:
      _pp_config_props in libavfilter.a(vf_pp.o)

解：添加libpostproc.a

TODO

[ ] 加上多线程
[ ] 回调
[ ] 封装framework

其他参考

ffmpeg4.1编译IOS版本及x264、fdk-aac -
https://www.jianshu.com/p/e4f2eb6f3eb8

FFmpeg源代码结构图 - 解码 - 雷霄骅(leixiaohua1020)的专栏 - CSDN博客
https://blog.csdn.net/leixiaohua1020/article/details/44220151

iOS: FFmpeg的使用一 - 当天真遇到现实 - 博客园
https://www.cnblogs.com/XYQ-208910/p/5651166.html

iOS：集成ijkplayer视频直播 - 当天真遇到现实 - 博客园
http://www.cnblogs.com/XYQ-208910/p/5856815.html

IOS视频压缩 - kouriba - ITeye博客
https://kouriba.iteye.com/blog/1629610

iOS 关于文件操作 NSFileManager -
https://www.jianshu.com/p/086ca6d2c5de

iOS进阶——数据处理之文件读写 -
https://www.jianshu.com/p/fbb997eb032d

6.17 使用MediaPlayer框架播放影片 [iOS开发-Xcode教程] -
https://www.jianshu.com/p/5464f8016909

通过iTunes共享文件到Document目录 -
https://www.jianshu.com/p/de59aafe1947

iOS之RTSP转MP4