M3U8

This is a most complete opensource library for parsing and generating of M3U8 playlists used in HTTP Live Streaming (Apple HLS) for internet video translations.

M3U8 is simple text format and parsing library for it must be simple too. It did not offer ways to play HLS or handle playlists over HTTP. So library features are:

• Support HLS specs up to version 5 of the protocol.
• Parsing and generation of master-playlists and media-playlists.
• Autodetect input streams as master or media playlists.
• Offer structures for keeping playlists metadata.
• Encryption keys support for use with DRM systems like Verimatrix etc.
• Support for non standard Google Widevine tags.

Library licensed under GPLv3. Copyleft by library authors (see AUTHORS).

Install

go get github.com/grafov/m3u8

or get releases from https://github.com/grafov/m3u8/releases

Documentation

Package online documentation (examples included) available at:

• http://gowalker.org/github.com/grafov/m3u8
• http://godoc.org/github.com/grafov/m3u8

Supported by the HLS protocol tags and their library support explained in M3U8 cheatsheet.

Examples

Parse playlist:

	f, err := os.Open("playlist.m3u8")
	if err != nil {
		panic(err)
	}
	p, listType, err := m3u8.DecodeFrom(bufio.NewReader(f), true)
	if err != nil {
		panic(err)
	}
	switch listType {
	case m3u8.MEDIA:
		mediapl := p.(*m3u8.MediaPlaylist)
		fmt.Printf("%+v\n", mediapl)
	case m3u8.MASTER:
		masterpl := p.(*m3u8.MasterPlaylist)
		fmt.Printf("%+v\n", masterpl)
	}

Then you get filled with parsed data structures. For master playlists you get Master struct with slice consists of pointers to Variant structures (which represent playlists to each bitrate). For media playlist parser returns MediaPlaylist structure with slice of Segments. Each segment is of MediaSegment type. See structure.go or full documentation (link below).

You may use API methods to fill structures or create them manually to generate playlists. Example of media playlist generation:

	p, e := m3u8.NewMediaPlaylist(3, 10) // with window of size 3 and capacity 10
	if e != nil {
		panic(fmt.Sprintf("Creating of media playlist failed: %s", e))
	}
	for i := 0; i < 5; i++ {
		e = p.Add(fmt.Sprintf("test%d.ts", i), 6.0, "")
		if e != nil {
			panic(fmt.Sprintf("Add segment #%d to a media playlist failed: %s", i, e))
		}
	}
	fmt.Println(p.Encode().String())

Library structure

Library has compact code and bundled in three files:

• structure.go — declares all structures related to playlists and their properties
• reader.go — playlist parser methods
• writer.go — playlist generator methods

Each file has own test suite placed in *_test.go accordingly.

Related links

• http://en.wikipedia.org/wiki/M3U
• http://en.wikipedia.org/wiki/HTTP_Live_Streaming
• http://gonze.com/playlists/playlist-format-survey.html

Library usage

This library was successfully used in streaming software developed for company where I worked several years ago. It was tested then in generating of VOD and Live streams and parsing of Widevine Live streams. Also the library used in opensource software so you may look at these apps for usage examples:

• HLS downloader
• Another HLS downloader
• HLS utils

M3U8 parsing/generation in other languages

• https://github.com/globocom/m3u8 in Python
• https://github.com/zencoder/m3uzi in Ruby
• https://github.com/Jeanvf/M3U8Paser in Objective C
• https://github.com/tedconf/node-m3u8 in Javascript
• http://sourceforge.net/projects/m3u8parser/ in Java
• https://github.com/karlll/erlm3u8 in Erlang

Project status

Project maintainers:

• Bradley Falzon @bradleyfalzon
• Alexander Grafov @grafov

Development rules:

• After complete testing and one week usage with my prober for HLS Stream Surfer it may be released as new library version.
• Each new API call or M3U8 tag accompanied by at least with one unit test till new release (this rule will be apply after v1.0).
• Versioning scheme follows http://semver.org rules (but versions till v1.0 not support bacward compatibility, see release notes carefully).

Project dashboard: https://waffle.io/grafov/m3u8

State of code coverage: https://gocover.io/github.com/grafov/m3u8

Roadmap

To version 1.0:

• Support all M3U8 tags up to latest version of specs.
• Code coverage by unit tests up to 90%