Javascript Project to Read & Write HLS Live Video Streaming Playlists inside Browser Using HTML5

 

hls-parser

Provides synchronous functions to read/write HLS playlists (conforms to the HLS spec rev.23the Apple Low-Latency Spec rev. 2020/02/05, and HLS.js’s Low-Latency spec)

Install

NPM 

Usage

 

 

 

 

API

HLS.parse(str)

Converts a text playlist into a structured JS object

params

Name Type Required Default Description
str string Yes N/A A text data that conforms to the HLS playlist spec

return value

An instance of either MasterPlaylist or MediaPlaylist (See Data format below.)

HLS.stringify(obj)

Converts a JS object into a plain text playlist

params

Name Type Required Default Description
obj MasterPlaylist or MediaPlaylist (See Data format below.) Yes N/A An object returned by HLS.parse() or a manually created object

return value

A text data that conforms to the HLS playlist spec

HLS.setOptions(obj)

Updates the option values

params

Name Type Required Default Description
obj Object Yes {} An object holding option values which will be used to overwrite the internal option values.
supported options
Name Type Default Description
strictMode boolean false If true, the function throws an error when parse/stringify failed. If false, the function just logs the error and continues to run.
allowClosedCaptionsNone boolean false If true, CLOSED-CAPTIONS attribute on the EXT-X-STREAM-INF tag will be set to the enumerated-string value NONE when there are no closed-captions. See CLOSED-CAPTIONS
silent boolean false If true, console.error will be suppressed.

HLS.getOptions()

Retrieves the current option values

return value

A cloned object containing the current option values

HLS.types

An object that holds all the classes described below.

Data format

This section describes the structure of the object returned by parse() method.

data structure

Data

Property Type Required Default Description
type string Yes N/A Either playlist or segment or part}

Playlist (extends Data)

Property Type Required Default Description
isMasterPlaylist boolean Yes N/A true if this playlist is a master playlist
uri string No undefined Playlist URL
version number No undefined See EXT-X-VERSION
independentSegments boolean No false See EXT-X-INDEPENDENT-SEGMENTS
start object({offset: number, precise: boolean}) No undefined See EXT-X-START
source string No undefined The unprocessed text of the playlist

MasterPlaylist (extends Playlist)

Property Type Required Default Description
variants [Variant] No [] See EXT-X-STREAM-INF and EXT-X-I-FRAME-STREAM-INF
currentVariant number No undefined Array index that points to the chosen item in variants
sessionDataList [SessionData] No [] See EXT-X-SESSION-DATA
sessionKeyList [Key] No [] See EXT-X-SESSION-KEY

Variant

Property Type Required Default Description
uri string Yes N/A URI of the variant playlist
isIFrameOnly boolean No undefined true if the variant is an I-frame media playlist. See EXT-X-I-FRAME-STREAM-INF
bandwidth number Yes N/A See BANDWIDTH attribute in EXT-X-STREAM-INF
averageBandwidth number No undefined See AVERAGE-BANDWIDTH attribute in EXT-X-STREAM-INF
score number No undefined See SCORE attribute in EXT-X-STREAM-INF
codecs string No undefined See CODECS attribute in EXT-X-STREAM-INF
resolution object ({width: number, height: number}) No undefined See RESOLUTION attribute in EXT-X-STREAM-INF
frameRate number No undefined See FRAME-RATE attribute in EXT-X-STREAM-INF
hdcpLevel string No undefined See HDCP-LEVEL attribute in EXT-X-STREAM-INF
allowedCpc [object ({format: string, cpcList: [string]})] No undefined See ALLOWED-CPC attribute in EXT-X-STREAM-INF
videoRange string {“SDR”,”HLG”,”PQ”} No undefined See VIDEO-RANGE attribute in EXT-X-STREAM-INF
stableVariantId string No undefined See STABLE-VARIANT-ID attribute in EXT-X-STREAM-INF
audio [Rendition(type=’AUDIO’)] No [] See AUDIO attribute in EXT-X-STREAM-INF
video [Rendition(type=’VIDEO’)] No [] See VIDEO attribute in EXT-X-STREAM-INF
subtitles [Rendition(type=’SUBTITLES’)] No [] See SUBTITLES attribute in EXT-X-STREAM-INF
closedCaptions [Rendition(type=’CLOSED-CAPTIONS’)] No [] See CLOSED-CAPTIONS attribute in EXT-X-STREAM-INF
currentRenditions object ({audio: number, video: number, subtitles: number, closedCaptions: number}) No {} A hash object that contains array indices that points to the chosen Rendition for each type

Rendition

Property Type Required Default Description
type string Yes N/A See TYPE attribute in EXT-X-MEDIA
uri string No undefined See URI attribute in EXT-X-MEDIA
groupId string Yes N/A See GROUP-ID attribute in EXT-X-MEDIA
language string No undefined See LANGUAGE attribute in EXT-X-MEDIA
assocLanguage string No undefined See ASSOC-LANGUAGE attribute in EXT-X-MEDIA
name string Yes N/A See NAME attribute in EXT-X-MEDIA
isDefault boolean No false See DEFAULT attribute in EXT-X-MEDIA
autoselect boolean No false See AUTOSELECT attribute in EXT-X-MEDIA
forced boolean No false See FORCED attribute in EXT-X-MEDIA
instreamId string No undefined See INSTREAM-ID attribute in EXT-X-MEDIA
characteristics string No undefined See CHARACTERISTICS attribute in EXT-X-MEDIA
channels string No undefined See CHANNELS attribute in EXT-X-MEDIA

SessionData

Property Type Required Default Description
id string Yes N/A See DATA-ID attribute in EXT-X-SESSION-DATA
value string No undefined See VALUE attribute in EXT-X-SESSION-DATA
uri string No undefined See URI attribute in EXT-X-SESSION-DATA
language string No undefined See LANGUAGE attribute in EXT-X-SESSION-DATA

MediaPlaylist (extends Playlist)

Property Type Required Default Description
targetDuration number Yes N/A See EXT-X-TARGETDURATION
mediaSequenceBase number No 0 See EXT-X-MEDIA-SEQUENCE
discontinuitySequenceBase number No 0 See EXT-X-DISCONTINUITY-SEQUENCE
endlist boolean No false See EXT-X-ENDLIST
playlistType string No undefined See EXT-X-PLAYLIST-TYPE
isIFrame boolean No undefined See EXT-X-I-FRAMES-ONLY
segments [Segment] No [] A list of available segments
prefetchSegments [PrefetchSegment] No [] A list of available prefetch segments
lowLatencyCompatibility object ({canBlockReload: boolean, canSkipUntil: number, holdBack: number, partHoldBack: number}) No undefined See CAN-BLOCK-RELOADCAN-SKIP-UNTILHOLD-BACK, and PART-HOLD-BACK attributes in EXT-X-SERVER-CONTROL
partTargetDuration number No* undefined *Required if the playlist contains one or more EXT-X-PART tags. See EXT-X-PART-INF
renditionReports [RenditionReport] No [] Update status of the associated renditions
skip number No 0 See EXT-X-SKIP

Segment (extends Data)

Property Type Required Default Description
uri string Yes* N/A URI of the media segment. *Not required if the segment contains EXT-X-PRELOAD-HINT tag
duration number Yes* N/A See EXTINF *Not required if the segment contains EXT-X-PRELOAD-HINT tag
title string No undefined See EXTINF
byterange object ({length: number, offset: number}) No undefined See EXT-X-BYTERANGE
discontinuity boolean No undefined See EXT-X-DISCONTINUITY
mediaSequenceNumber number No 0 See the description about ‘Media Sequence Number’ in 3. Media Segments
discontinuitySequence number No 0 See the description about ‘Discontinuity Sequence Number’ in 6.2.1. General Server Responsibilities
key Key No undefined See EXT-X-KEY
map MediaInitializationSection No undefined See EXT-X-MAP
programDateTime Date No undefined See EXT-X-PROGRAM-DATE-TIME
dateRange DateRange No undefined See EXT-X-DATERANGE
markers [SpliceInfo] No [] SCTE-35 messages associated with this segment
parts [PartialSegment] No [] Partial Segments that constitute this segment

PartialSegment (extends Data)

Property Type Required Default Description
hint boolean No false true indicates a hinted resource (TYPE=PART) See EXT-X-PRELOAD-HINT
uri string Yes N/A See URI attribute in EXT-X-PART
duration number Yes* N/A See DURATION attribute in EXT-X-PART *Not required if hint is true
independent boolean No undefined See INDEPENDENT attribute in EXT-X-PART
byterange object ({length: number, offset: number}) No undefined See BYTERANGE attribute in EXT-X-PART
gap boolean No undefined See GAP attribute in EXT-X-PART

PrefetchSegment (extends Data)

Property Type Required Default Description
uri string Yes N/A See value of EXT-X-PREFETCH
discontinuity boolean No undefined See EXT-X-PREFETCH-DISCONTINUITY
mediaSequenceNumber number No 0 See the description about ‘Media Sequence Number’ in 3. Media Segments
discontinuitySequence number No 0 See the description about ‘Discontinuity Sequence Number’ in 6.2.1. General Server Responsibilities

Key

Property Type Required Default Description
method string Yes N/A See METHOD attribute in EXT-X-KEY
uri string No undefined See URI attribute in EXT-X-KEY
iv Buffer(length=16) No undefined See IV attribute in EXT-X-KEY
format string No undefined See KEYFORMAT attribute in EXT-X-KEY
formatVersion string No undefined See KEYFORMATVERSIONS attribute in EXT-X-KEY

MediaInitializationSection

Property Type Required Default Description
hint boolean No false true indicates a hinted resource (TYPE=MAP) See EXT-X-PRELOAD-HINT
uri string Yes N/A See URI attribute in EXT-X-MAP
byterange object ({length: number, offset: number}) No undefined See BYTERANGE attribute in EXT-X-MAP

DateRange

Property Type Required Default Description
id string Yes N/A See ID attribute in EXT-X-DATERANGE
classId string No undefined See CLASS attribute in EXT-X-DATERANGE
start Date No undefined See START-DATE attribute in EXT-X-DATERANGE
end Date No undefined See END-DATE attribute in EXT-X-DATERANGE
duration number No undefined See DURATION attribute in EXT-X-DATERANGE
plannedDuration number No undefined See PLANNED-DURATION attribute in EXT-X-DATERANGE
endOnNext boolean No undefined See END-ON-NEXT attribute in EXT-X-DATERANGE
attributes object No {} A hash object that holds SCTE35 attributes and user defined attributes. See SCTE35-* and X- attributes in EXT-X-DATERANGE

SpliceInfo

Only EXT-X-CUE-OUT and EXT-X-CUE-IN tags are supported. Other SCTE-35-related tags are stored as raw (string) values.

Property Type Required Default Description
type string Yes N/A {‘OUT’, ‘IN’, ‘RAW’}
duration number No undefined Required if the type is ‘OUT’
tagName string No undefined Holds the tag name if any unsupported tag are found. Required if the type is ‘RAW’
value string No undefined Holds a raw (string) value for the unsupported tag.

RenditionReport

Property Type Required Default Description
uri string Yes N/A See URI attribute in EXT-X-RENDITION-REPORT
lastMSN number No undefined See LAST-MSN attribute in EXT-X-RENDITION-REPORT
lastPart number No undefined See LAST-PART attribute in EXT-X-RENDITION-REPORT

 

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