Since last essay, we have known the basic concepts of media files. Then we need to solve some real-world problems by using the command-line tool ffmpeg.

Overview

Before we gets our hands on the actual commands, let us review the procedure of FFmpeg processing media files:

 _______              ______________
|       |            |              |
| input |  demuxer   | encoded data |   decoder
| file  | ---------> | packets      | -----+
|_______|            |______________|      |
                                           v
                                       _________
                                      |         |
                                      | decoded |
                                      | frames  |
                                      |_________|
 ________             ______________       |
|        |           |              |      |
| output | <-------- | encoded data | <----+
| file   |   muxer   | packets      |   encoder
|________|           |______________|

Refer to FFmpeg - Documentation

Did you once meet the situation that you wanted to upload some videos you just edited to some website, but told the format is not supported? Or you once wanted to play some video you just downloaded, but told the format is not supported by the video player? Then we may need the help of FFmpeg to solve that issue.