ffmpeg-libav-tutorial

[🇨🇳](/README-cn.md "Simplified Chinese")
[🇰🇷](/README-ko.md "Korean")
[🇪🇸](/README-es.md "Spanish")
[🇻🇳](/README-vn.md "Vietnamese")
[🇧🇷](/README-pt.md "Portuguese")
[🇷🇺](/README-ru.md "Russian")

[![license](https://img.shields.io/badge/license-BSD--3--Clause-blue.svg)](https://img.shields.io/badge/license-BSD--3--Clause-blue.svg)

I was looking for a tutorial/book that would teach me how to start to use [FFmpeg](https://www.ffmpeg.org/) as a library (a.k.a. libav) and then I found the ["How to write a video player in less than 1k lines"](http://dranger.com/ffmpeg/) tutorial.
Unfortunately it was deprecated, so I decided to write this one.

Most of the code in here will be in C **but don't worry**: you can easily understand and apply it to your preferred language.
FFmpeg libav has lots of bindings for many languages like [python](https://pyav.org/), [go](https://github.com/imkira/go-libav) and even if your language doesn't have it, you can still support it through the `ffi` (here's an example with [Lua](https://github.com/daurnimator/ffmpeg-lua-ffi/blob/master/init.lua)).

We'll start with a quick lesson about what is video, audio, codec and container and then we'll go to a crash course on how to use `FFmpeg` command line and finally we'll write code, feel free to skip directly to[ ](http://newmediarockstars.com/wp-content/uploads/2015/11/nintendo-direct-iwata.jpg)the section [Learn FFmpeg libav the Hard Way.](#learn-ffmpeg-libav-the-hard-way)

Some people used to say that the Internet video streaming is the future of the traditional TV, in any case, the FFmpeg is something that is worth studying.

__Table of Contents__

* [Intro](#intro)
  * [video - what you see!](#video---what-you-see)
  * [audio - what you listen!](#audio---what-you-listen)
  * [codec - shrinking data](#codec---shrinking-data)
  * [container - a comfy place for audio and video](#container---a-comfy-place-for-audio-and-video)
* [FFmpeg - command line](#ffmpeg---command-line)
  * [FFmpeg command line tool 101](#ffmpeg-command-line-tool-101)
* [Common video operations](#common-video-operations)
  * [Transcoding](#transcoding)
  * [Transmuxing](#transmuxing)
  * [Transrating](#transrating)
  * [Transsizing](#transsizing)
  * [Bonus Round: Adaptive Streaming](#bonus-round-adaptive-streaming)
  * [Going beyond](#going-beyond)
* [Learn FFmpeg libav the Hard Way](#learn-ffmpeg-libav-the-hard-way)
  * [Chapter 0 - The infamous hello world](#chapter-0---the-infamous-hello-world)
    * [FFmpeg libav architecture](#ffmpeg-libav-architecture)
  * [Chapter 1 - timing](#chapter-1---syncing-audio-and-video)
  * [Chapter 2 - remuxing](#chapter-2---remuxing)
  * [Chapter 3 - transcoding](#chapter-3---transcoding)

# Intro

## video - what you see!

If you have a sequence series of images and change them at a given frequency (let's say [24 images per second](https://www.filmindependent.org/blog/hacking-film-24-frames-per-second/)), you will create an [illusion of movement](https://en.wikipedia