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package m3u8
import (
// This file defines the data structures related to the package.
const (
// refs: Protocol version compatibility in section 7
minver = uint8(3)
// DATETIME time format
DATETIME = time.RFC3339Nano // Format for EXT-X-PROGRAM-DATE-TIME
// ListType list type
type ListType uint
const (
// use 0 for undefined types
// MASTER type
MASTER ListType = iota + 1
// MEDIA type
// MediaType for EXT-X-PLAYLIST-TYPE tag
type MediaType uint
const (
// use 0 for undefined types
// EVENT type
EVENT MediaType = iota + 1
// VOD type
// MediaPlaylist This structure represents a single bitrate playlist aka media playlist.
// It is related to both a simple media playlist and a sliding window media playlist.
// URI lines in the Playlist point to media segments.
// Simple Media Playlist file sample:
// #EXTM3U
// #EXTINF:5219.2,
// Sample of Sliding Window Media Playlist, using HTTPS:
// #EXTM3U
// #EXTINF:7.975,
// #EXTINF:7.941,
// #EXTINF:7.975,
type MediaPlaylist struct {
Segments []*MediaSegment
MediaType MediaType
buf bytes.Buffer
Key *Key // EXT-X-KEY is optional encryption key displayed before any segments (default key for the playlist)
Map *Map // EXT-X-MAP is optional tag specifies how to obtain the Media Initialization Section (default map for the playlist)
WV *WV // Widevine related tags outside of M3U8 specs
Args string // optional arguments placed after URIs (URI?Args)
TargetDuration float64
Winsize uint // max number of segments displayed in an encoded playlist; need set to zero for VOD playlists
capacity uint // total capacity of slice used for the playlist
head uint // head of FIFO, we add segments to head
tail uint // tail of FIFO, we remove segments from tail
count uint // number of segments added to the playlist
Ver uint8
Iframe bool // EXT-X-I-FRAMES-ONLY
Closed bool // is this VOD (closed) or Live (sliding) playlist?
durationAsInt bool // output durations as integers of floats?
// MasterPlaylist This structure represents a master playlist which combines media playlists for multiple bitrates.
// URI lines in the playlist identify media playlists.
// Sample of Master Playlist file:
// #EXTM3U
type MasterPlaylist struct {
Variants []*Variant
Args string // optional arguments placed after URI (URI?Args)
CypherVersion string // non-standard tag for Widevine (see also WV struct)
buf bytes.Buffer
Ver uint8
// Variant This structure represents variants for master playlist.
// Variants included in a master playlist and point to media playlists.
type Variant struct {
URI string
Chunklist *MediaPlaylist
// VariantParams This structure represents additional parameters for a variant
type VariantParams struct {
ProgramID uint32
Bandwidth uint32
Codecs string
Resolution string
Audio string // EXT-X-STREAM-INF only
Video string
Subtitles string // EXT-X-STREAM-INF only
Captions string // EXT-X-STREAM-INF only
Name string // EXT-X-STREAM-INF only (non standard Wowza/JWPlayer extension to name the variant/quality in UA)
Alternatives []*Alternative // EXT-X-MEDIA
// Alternative This structure represents EXT-X-MEDIA tag in variants.
type Alternative struct {
GroupID string
URI string
Type string
Language string
Name string
Default bool
Autoselect string
Forced string
Characteristics string
Subtitles string
// MediaSegment This structure represents a media segment included in a media playlist.
// Media segment may be encrypted.
// Widevine supports own tags for encryption metadata.
type MediaSegment struct {
SeqID uint64
Title string // optional second parameter for EXTINF tag
URI string
Duration float64 // first parameter for EXTINF tag; duration must be integers if protocol version is less than 3 but we are always keep them float
Limit int64 // EXT-X-BYTERANGE <n> is length in bytes for the file under URI
Offset int64 // EXT-X-BYTERANGE [@o] is offset from the start of the file under URI
Key *Key // EXT-X-KEY displayed before the segment and means changing of encryption key (in theory each segment may have own key)
Map *Map // EXT-X-MAP displayed before the segment
Discontinuity bool // EXT-X-DISCONTINUITY indicates an encoding discontinuity between the media segment that follows it and the one that preceded it (i.e. file format, number and type of tracks, encoding parameters, encoding sequence, timestamp sequence)
SCTE *SCTE // EXT-SCTE35 used for Ad signaling in HLS
ProgramDateTime time.Time // EXT-X-PROGRAM-DATE-TIME tag associates the first sample of a media segment with an absolute date and/or time
// SCTE SCTE struct
type SCTE struct {
Cue string
ID string
Time float64
// Key This structure represents information about stream encryption.
// Realizes EXT-X-KEY tag.
type Key struct {
Method string
URI string
IV string
Keyformat string
Keyformatversions string
// Map This structure represents specifies how to obtain the Media
// Initialization Section required to parse the applicable
// Media Segments.
// It applies to every Media Segment that appears after it in the
// Playlist until the next EXT-X-MAP tag or until the end of the
// playlist.
// Realizes EXT-MAP tag.
type Map struct {
URI string
Limit int64 // <n> is length in bytes for the file under URI
Offset int64 // [@o] is offset from the start of the file under URI
// WV This structure represents metadata for Google Widevine playlists.
// This format not described in IETF draft but provied by Widevine Live Packager as
// additional tags with #WV-prefix.
type WV struct {
AudioChannels uint
AudioFormat uint
AudioProfileIDC uint
AudioSampleSize uint
AudioSamplingFrequency uint
CypherVersion string
ECM string
VideoFormat uint
VideoFrameRate uint
VideoLevelIDC uint
VideoProfileIDC uint
VideoResolution string
VideoSAR string
// Playlist Interface applied to various playlist types.
type Playlist interface {
Encode() *bytes.Buffer
Decode(bytes.Buffer, bool) error
DecodeFrom(reader io.Reader, strict bool) error
String() string
// Internal structure for decoding a line of input stream with a list type detection
type decodingState struct {
listType ListType
m3u bool
tagWV bool
tagStreamInf bool
tagInf bool
tagSCTE35 bool
tagRange bool
tagDiscontinuity bool
tagProgramDateTime bool
tagKey bool
tagMap bool
programDateTime time.Time
limit int64
offset int64
duration float64
title string
variant *Variant
alternatives []*Alternative
xkey *Key
xmap *Map
scte *SCTE