ffmpeg -codecs | grep mp3
可以查看ffmpeg是否把mp3编解码模块编译进去了。
libmp3lame is the mp3 encoder for ffmpeg. It needs to be enabled during configure stage of the build. --enable-libmp3lame should enable it. Also you should libmp3lame-dev installed. I follow this guide to install ffmpeg: https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide
$ ffmpeg -codecs | grep mp3
ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
built on Jan 25 2013 15:16:27 with llvm_gcc 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2335.15.00)
configuration: --prefix=/usr/local/Cellar/ffmpeg/0.11.1 --enable-shared --enable-gpl --enable-version3 --enable-nonfree --enable-hardcoded-tables --cc=/usr/bin/llvm-gcc --host-cflags='-Os -w -pipe -march=core2 -msse4 -mmacosx-version-min=10.7' --host-ldflags=-L/usr/local/lib --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libxvid
libavutil 51. 54.100 / 51. 54.100
libavcodec 54. 23.100 / 54. 23.100
libavformat 54. 6.100 / 54. 6.100
libavdevice 54. 0.100 / 54. 0.100
libavfilter 2. 77.100 / 2. 77.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 15.100 / 0. 15.100
libpostproc 52. 0.100 / 52. 0.100
EA libmp3lame libmp3lame MP3 (MPEG audio layer 3)
D A D mp3 MP3 (MPEG audio layer 3)
D A D mp3adu ADU (Application Data Unit) MP3 (MPEG audio layer 3)
D A D mp3adufloat ADU (Application Data Unit) MP3 (MPEG audio layer 3)
D A D mp3float MP3 (MPEG audio layer 3)
D A D mp3on4 MP3onMP4
D A D mp3on4float MP3onMP4
You can see that E (encoder) is available with libmp3lame.
ffmpeg 命令行查看音视频文件的信息:
ffmpeg -i filename.flv 或者 ffprobe video.flv