CentOS7.4 yum和源码安装ffmpeg 将amr格式音频转码为mp3

源码安装：

安装依赖：

# yum install nasm yasm

安装依赖：

# wget https://nchc.dl.sourceforge.net/project/lame/lame/3.100/lame-3.100.tar.gz

# tar -zxvf lame-3.100.tar.gz 

# cd lame-3.100

# ./configure 

# make

# make install

添加软连接，不然转码的时候要报 ffmpeg: error while loading shared libraries: libmp3lame.so.0: cannot open shared object file: No such file or directory：

ln -s /usr/local/lib/libmp3lame.so.0 /usr/lib64/libmp3lame.so.0

安装ffmpeg：

git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg

# ./configure --enable-libmp3lame

# make && make install

转码测试：

[root@iZ2ze9jbuu3xabz2yumb7sZ ~]# ffmpeg -i test.amr test.mp3

ffmpeg version N-89404-gdc7d5f9 Copyright (c) 2000-2017 the FFmpeg developers

  built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-16)

  configuration: --enable-libmp3lame

  libavutil      56.  5.100 / 56.  5.100

  libavcodec     58.  6.103 / 58.  6.103

  libavformat    58.  2.103 / 58.  2.103

  libavdevice    58.  0.100 / 58.  0.100

  libavfilter     7.  7.100 /  7.  7.100

  libswscale      5.  0.101 /  5.  0.101

  libswresample   3.  0.101 /  3.  0.101

[amr @ 0x2ad4360] Estimating duration from bitrate, this may be inaccurate

Input #0, amr, from 'test.amr':

  Duration: 00:03:01.14, bitrate: 12 kb/s

    Stream #0:0: Audio: amr_nb (samr / 0x726D6173), 8000 Hz, mono, flt

Stream mapping:

  Stream #0:0 -> #0:0 (amr_nb (amrnb) -> mp3 (libmp3lame))

Press [q] to stop, [?] for help

Output #0, mp3, to 'test.mp3':

  Metadata:

    TSSE            : Lavf58.2.103

    Stream #0:0: Audio: mp3 (libmp3lame), 8000 Hz, mono, fltp

    Metadata:

      encoder         : Lavc58.6.103 libmp3lame

size=     177kB time=00:03:01.15 bitrate=   8.0kbits/s speed= 139x    

video:0kB audio:177kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.143412%

[root@iZ2ze9jbuu3xabz2yumb7sZ ~]# ll

total 1964

drwxr-xr-x 19 root root    4096 Dec  7 11:30 ffmpeg

drwxr-xr-x 15 1001 1001    4096 Dec  7 11:16 lame-3.100

-rw-r--r--  1 root root 1524133 Oct 14 04:33 lame-3.100.tar.gz

-rw-r--r--  1 root root  289830 Dec  6 16:33 test.amr

-rw-r--r--  1 root root  181556 Dec  7 11:57 test.mp3

2017.12.28 更新：

由于我们是调用微信的录音接口来做的，转为MP3后音质很不理想，与源amr录音相差有点大，所以研究转码参数后又做了进一步的调整，加上下面的参数进行转码：

ffmpeg -i source.amr -acodec libmp3lame -ar 24000 -vol 500 target.vol500.mp3

-acodec 指定编解码方式

-ar 24000 采样率设为24000

-vol 声音加大为500

其他参数参考：

http://blog.csdn.net/sunbingzibo/article/details/1649137

YUM安装

[10:18:46][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# cat /etc/redhat-release 

[10:18:46]CentOS Linux release 7.4.1708 (Core) 

[10:23:30][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# wget http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm

[10:23:38][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# rpm -ivh nux-dextop-release-0-1.el7.nux.noarch.rpm 

[10:23:53][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# yum install ffmpeg

[10:25:15][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# ffmpeg -version

[10:25:15]ffmpeg version 2.6.8 Copyright (c) 2000-2016 the FFmpeg developers

[10:25:15]built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)

[10:25:15]configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-gnutls --enable-ladspa --enable-libass --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-nonfree --enable-libfdk-aac --enable-nonfree --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libx264 --enable-libx265 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect

[10:25:15]libavutil      54. 20.100 / 54. 20.100

[10:25:15]libavcodec     56. 26.100 / 56. 26.100

[10:25:15]libavformat    56. 25.101 / 56. 25.101

[10:25:15]libavdevice    56.  4.100 / 56.  4.100

[10:25:15]libavfilter     5. 11.102 /  5. 11.102

[10:25:15]libavresample   2.  1.  0 /  2.  1.  0

[10:25:15]libswscale      3.  1.101 /  3.  1.101

[10:25:15]libswresample   1.  1.100 /  1.  1.100

[10:25:15]libpostproc    53.  3.100 / 53.  3.100

转码测试：将amr格式的音频转为mp3格式

[10:25:43][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# ffmpeg -i test.amr  test.mp3

[10:25:43]ffmpeg version 2.6.8 Copyright (c) 2000-2016 the FFmpeg developers

[10:25:43]  built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-4)

[10:25:43]  configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --enable-bzlib --disable-crystalhd --enable-gnutls --enable-ladspa --enable-libass --enable-libcdio --enable-libdc1394 --enable-libfaac --enable-nonfree --enable-libfdk-aac --enable-nonfree --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libx264 --enable-libx265 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect

[10:25:43]  libavutil      54. 20.100 / 54. 20.100

[10:25:43]  libavcodec     56. 26.100 / 56. 26.100

[10:25:43]  libavformat    56. 25.101 / 56. 25.101

[10:25:43]  libavdevice    56.  4.100 / 56.  4.100

[10:25:43]  libavfilter     5. 11.102 /  5. 11.102

[10:25:43]  libavresample   2.  1.  0 /  2.  1.  0

[10:25:43]  libswscale      3.  1.101 /  3.  1.101

[10:25:43]  libswresample   1.  1.100 /  1.  1.100

[10:25:43]  libpostproc    53.  3.100 / 53.  3.100

[10:25:43][amr @ 0x11c74a0] Estimating duration from bitrate, this may be inaccurate

[10:25:43]Input #0, amr, from 'test.amr':

[10:25:43]  Duration: 00:03:01.14, bitrate: 12 kb/s

[10:25:43]    Stream #0:0: Audio: amr_nb (samr / 0x726D6173), 8000 Hz, mono, flt, 12 kb/s

[10:25:43]Output #0, mp3, to 'test.mp3':

[10:25:43]  Metadata:

[10:25:43]    TSSE            : Lavf56.25.101

[10:25:43]    Stream #0:0: Audio: mp3 (libmp3lame), 8000 Hz, mono, fltp

[10:25:43]    Metadata:

[10:25:43]      encoder         : Lavc56.26.100 libmp3lame

[10:25:43]Stream mapping:

[10:25:43]  Stream #0:0 -> #0:0 (amr_nb (amrnb) -> mp3 (libmp3lame))

[10:25:43]Press [q] to stop, [?] for help

[10:25:43]test.amr: Input/output error7.67 bitrate=   8.0kbits/s    

[10:25:43]size=     177kB time=00:03:01.15 bitrate=   8.0kbits/s    

[10:25:43]video:0kB audio:177kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.143963%

[10:25:48][root@iZ2ze9jbuu3xabz2yumb7sZ ~]# ll

[10:25:48]total 476

[10:25:48]-rw-r--r-- 1 root root   9844 Apr 27  2014 nux-dextop-release-0-1.el7.nux.noarch.rpm

[10:25:48]-rw-r--r-- 1 root root 289830 Dec  6 16:33 test.amr

[10:25:48]-rw-r--r-- 1 root root 181557 Dec  7 10:25 test.mp3