FFmpeg是什么呢？
A complete, cross-platform solution to record, convert and stream audio and video.
一个完全的，跨平台的记录，转换音视频流的解决方案。
官网地址：
http://ffmpeg.org/
源码下载地址：
http://ffmpeg.org/download.html
本机操作系统：Ubuntu 14.04
下载完成之后解压生成一个ffmpeg-4.0.1文件夹。
文件夹里有一个INSTALL.md 安装指导文件，安装三部曲：./configure; make; make install;
./configure --disable-x86asm
make
sudo make install
还有一个README.md 文件，
FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.
## Libraries
* `libavcodec` provides implementation of a wider range of codecs.
* `libavformat` implements streaming protocols, container formats and basic I/O access.
* `libavutil` includes hashers, decompressors and miscellaneous utility functions.
* `libavfilter` provides a mean to alter decoded Audio and Video through chain of filters.
* `libavdevice` provides an abstraction to access capture and playback devices.
* `libswresample` implements audio mixing and resampling routines.
* `libswscale` implements color conversion and scaling routines.
## Tools
* [ffmpeg](https://ffmpeg.org/ffmpeg.html) is a command line toolbox to
manipulate, convert and stream multimedia content.
* [ffplay](https://ffmpeg.org/ffplay.html) is a minimalistic multimedia player.
* [ffprobe](https://ffmpeg.org/ffprobe.html) is a simple analysis tool to inspect
multimedia content.
* Additional small tools such as `aviocat`, `ismindex` and `qt-faststart`.
接下来的文章介绍是以官网http://ffmpeg.org/documentation.html为基础，分为六大部分，
(1) Command Line Tools Documentation;
(2) Components Documentation;
(3) Libraries Documentation;
(4) General Documentation;
(5) Community Contributed Documentation