dash.js

Module: Settings

Define the configuration parameters of Dash.js MediaPlayer.

Source:
See:
  • PlayerSettings for further information about the supported configuration properties.

Type Definitions

AbrSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
movingAverageMethod string <optional>
 "slidingWindow"

Sets the moving average method used for smoothing throughput estimates.

Valid methods are "slidingWindow" and "ewma".

The call has no effect if an invalid method is passed.

The sliding window moving average method computes the average throughput using the last four segments downloaded.

If the stream is live (as opposed to VOD), then only the last three segments are used.

If wide variations in throughput are detected, the number of segments can be dynamically increased to avoid oscillations.

The exponentially weighted moving average (EWMA) method computes the average using exponential smoothing.

Two separate estimates are maintained, a fast one with a three-second half life and a slow one with an eight-second half life.

The throughput estimate at any time is the minimum of the fast and slow estimates.

This allows a fast reaction to a bandwidth drop and prevents oscillations on bandwidth spikes.
ABRStrategy string <optional>
 "abrDynamic"

Returns the current ABR strategy being used: "abrDynamic", "abrBola" or "abrThroughput".
trackSwitchMode object <optional>
 {video: "neverReplace", audio: "alwaysReplace"}
additionalAbrRules object <optional>
 {insufficientBufferRule: true,switchHistoryRule: true,droppedFramesRule: true,abandonRequestsRule: true}

Enable/Disable additional ABR rules in case ABRStrategy is set to "abrDynamic", "abrBola" or "abrThroughput".
bandwidthSafetyFactor number <optional>
 0.9

Standard ABR throughput rules multiply the throughput by this value.

It should be between 0 and 1, with lower values giving less rebuffering (but also lower quality).
useDefaultABRRules boolean <optional>
 true

Should the default ABR rules be used, or the custom ones added.
useDeadTimeLatency boolean <optional>
 true

If true, only the download portion will be considered part of the download bitrate and latency will be regarded as static.

If false, the reciprocal of the whole transfer time will be used.
limitBitrateByPortal boolean <optional>
 false

If true, the size of the video portal will limit the max chosen video resolution.
usePixelRatioInLimitBitrateByPortal boolean <optional>
 false

Sets whether to take into account the device's pixel ratio when defining the portal dimensions.

Useful on, for example, retina displays.
maxBitrate module:Settings~AudioVideoSettings <optional>
 {audio: -1, video: -1}

The maximum bitrate that the ABR algorithms will choose. This value is specified in kbps.

Use -1 for no limit.
minBitrate module:Settings~AudioVideoSettings <optional>
 {audio: -1, video: -1}

The minimum bitrate that the ABR algorithms will choose. This value is specified in kbps.

Use -1 for no limit.
maxRepresentationRatio module:Settings~AudioVideoSettings <optional>
 {audio: 1, video: 1}

When switching multi-bitrate content (auto or manual mode) this property specifies the maximum representation allowed, as a proportion of the size of the representation set.

You can set or remove this cap at anytime before or during playback.

To clear this setting you set the value to 1.

If both this and maxAllowedBitrate are defined, maxAllowedBitrate is evaluated first, then maxAllowedRepresentation, i.e. the lowest value from executing these rules is used.

This feature is typically used to reserve higher representations for playback only when connected over a fast connection.
initialBitrate module:Settings~AudioVideoSettings <optional>
 {audio: -1, video: -1}

Explicitly set the starting bitrate for audio or video. This value is specified in kbps.

Use -1 to let the player decide.
initialRepresentationRatio module:Settings~AudioVideoSettings <optional>
 {audio: -1, video: -1}

Explicitly set the initial representation ratio.

If initalBitrate is specified, this is ignored.
autoSwitchBitrate module:Settings~AudioVideoSettings <optional>
 {audio: true, video: true}

Indicates whether the player should enable ABR algorithms to switch the bitrate.
fetchThroughputCalculationMode string <optional>
 "abrFetchThroughputCalculationDownloadedData"

Algorithm to determine the throughput in case the Fetch API is used for low latency streaming.

For details please check the samples section and FetchLoader.js.
Source:

AudioVideoSettings

Type:
  • Object
Properties:
Name Type Argument Description
audio number | boolean | string <optional>

Configuration for audio media type of tracks.
video number | boolean | string <optional>

Configuration for video media type of tracks.
Source:

Buffer

Type:
  • Object
Properties:
Name Type Argument Default Description
enableSeekDecorrelationFix boolean <optional>
 false

Enables a workaround for playback start on some devices, e.g. WebOS 4.9.
It is necessary because some browsers do not support setting currentTime on video element to a value that is outside of current buffer.

If you experience unexpected seeking triggered by BufferController, you can try setting this value to false.
fastSwitchEnabled boolean <optional>
 true

When enabled, after an ABR up-switch in quality, instead of requesting and appending the next fragment at the end of the current buffer range it is requested and appended closer to the current time.

When enabled, The maximum time to render a higher quality is current time + (1.5 * fragment duration).

Note, When ABR down-switch is detected, we appended the lower quality at the end of the buffer range to preserve the
higher quality media for as long as possible.

If enabled, it should be noted there are a few cases when the client will not replace inside buffer range but rather just append at the end.

  1. When the buffer level is less than one fragment duration.
  2. The client is in an Abandonment State due to recent fragment abandonment event.

Known issues:

  1. In IE11 with auto switching off, if a user switches to a quality they can not download in time the fragment may be appended in the same range as the playhead or even in the past, in IE11 it may cause a stutter or stall in playback.
flushBufferAtTrackSwitch boolean <optional>
 false

When enabled, after a track switch and in case buffer is being replaced, the video element is flushed (seek at current playback time) once a segment of the new track is appended in buffer in order to force video decoder to play new track.

This can be required on some devices like GoogleCast devices to make track switching functional.

Otherwise track switching will be effective only once after previous buffered track is fully consumed.
reuseExistingSourceBuffers boolean <optional>
 true

Enable reuse of existing MediaSource Sourcebuffers during period transition.
bufferPruningInterval number <optional>
 10

The interval of pruning buffer in seconds.
bufferToKeep number <optional>
 20

This value influences the buffer pruning logic.

Allows you to modify the buffer that is kept in source buffer in seconds.
0|-----------bufferToPrune-----------|-----bufferToKeep-----|currentTime|
bufferTimeAtTopQuality number <optional>
 30

The time that the internal buffer target will be set to once playing the top quality.

If there are multiple bitrates in your adaptation, and the media is playing at the highest bitrate, then we try to build a larger buffer at the top quality to increase stability and to maintain media quality.
bufferTimeAtTopQualityLongForm number <optional>
 60

The time that the internal buffer target will be set to once playing the top quality for long form content.
longFormContentDurationThreshold number <optional>
 600

The threshold which defines if the media is considered long form content.

This will directly affect the buffer targets when playing back at the top quality.
initialBufferLevel number <optional>
 NaN

Initial buffer level before playback starts
stableBufferTime number <optional>
 12

The time that the internal buffer target will be set to post startup/seeks (NOT top quality).

When the time is set higher than the default you will have to wait longer to see automatic bitrate switches but will have a larger buffer which will increase stability.
stallThreshold number <optional>
 0.3

Stall threshold used in BufferController.js to determine whether a track should still be changed and which buffer range to prune.
useAppendWindow boolean <optional>
 true

Specifies if the appendWindow attributes of the MSE SourceBuffers should be set according to content duration from manifest.
setStallState boolean <optional>
 true

Specifies if we fire manual waiting events once the stall threshold is reached
avoidCurrentTimeRangePruning boolean <optional>
 false

Avoids pruning of the buffered range that contains the current playback time.

That buffered range is likely to have been enqueued for playback. Pruning it causes a flush and reenqueue in WPE and WebKitGTK based browsers. This stresses the video decoder and can cause stuttering on embedded platforms.
useChangeTypeForTrackSwitch boolean <optional>
 true

If this flag is set to true then dash.js will use the MSE v.2 API call "changeType()" before switching to a different track.
Note that some platforms might not implement the changeType functio. dash.js is checking for the availability before trying to call it.
mediaSourceDurationInfinity boolean <optional>
 true

If this flag is set to true then dash.js will allow Infinity to be set as the MediaSource duration otherwise the duration will be set to Math.pow(2,32) instead of Infinity to allow appending segments indefinitely.
Some platforms such as WebOS 4.x have issues with seeking when duration is set to Infinity, setting this flag to false resolve this.
resetSourceBuffersForTrackSwitch boolean <optional>
 false

When switching to a track that is not compatible with the currently active MSE SourceBuffers, MSE will be reset. This happens when we switch codecs on a system
that does not properly implement "changeType()", such as webOS 4.0 and before.
Source:

CachingInfoSettings

Type:
  • Object
Properties:
Name Type Argument Description
enable boolean <optional>

Enable or disable the caching feature.
ttl number <optional>

Time to live.

A value defined in milliseconds representing how log to cache the settings for.
Source:

Capabilities

Type:
  • Object
Properties:
Name Type Argument Default Description
filterUnsupportedEssentialProperties boolean <optional>
 true

Enable to filter all the AdaptationSets and Representations which contain an unsupported <EssentialProperty> element.
useMediaCapabilitiesApi boolean <optional>
 false

Enable to use the MediaCapabilities API to check whether codecs are supported. If disabled MSE.isTypeSupported will be used instead.
Source:

CmcdSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
enable boolean <optional>
 false

Enable or disable the CMCD reporting.
sid string <optional>

GUID identifying the current playback session.

Should be in UUID format.

If not specified a UUID will be automatically generated.
cid string <optional>

A unique string to identify the current content.

If not specified it will be a hash of the MPD url.
rtp number <optional>

The requested maximum throughput that the client considers sufficient for delivery of the asset.

If not specified this value will be dynamically calculated in the CMCDModel based on the current buffer level.
rtpSafetyFactor number <optional>
 5

This value is used as a factor for the rtp value calculation: rtp = minBandwidth * rtpSafetyFactor

If not specified this value defaults to 5. Note that this value is only used when no static rtp value is defined.
mode number <optional>
 "query"

The method to use to attach cmcd metrics to the requests. 'query' to use query parameters, 'header' to use http headers.

If not specified this value defaults to 'query'.
enabledKeys Array.<string> <optional>

This value is used to specify the desired CMCD parameters. Parameters not included in this list are not reported.
Source:

CmsdAbrSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
applyMb boolean <optional>
 false

Set to true if dash.js should apply CMSD maximum suggested bitrate in ABR logic.
etpWeightRatio number <optional>
 0

Sets the weight ratio (between 0 and 1) that shall be applied on CMSD estimated throuhgput compared to measured throughput when calculating throughput.
Source:

CmsdSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
enabled boolean <optional>
 false

Enable or disable the CMSD response headers parsing.
abr module:Settings~CmsdAbrSettings <optional>

Sets additional ABR rules based on CMSD response headers.
Source:

DebugSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
logLevel number <optional>
 dashjs.Debug.LOG_LEVEL_WARNING

Sets up the log level. The levels are cumulative.

For example, if you set the log level to dashjs.Debug.LOG_LEVEL_WARNING all warnings, errors and fatals will be logged.

Possible values.

  • dashjs.Debug.LOG_LEVEL_NONE
    No message is written in the browser console.

  • dashjs.Debug.LOG_LEVEL_FATAL
    Log fatal errors.
    An error is considered fatal when it causes playback to fail completely.

  • dashjs.Debug.LOG_LEVEL_ERROR
    Log error messages.

  • dashjs.Debug.LOG_LEVEL_WARNING
    Log warning messages.

  • dashjs.Debug.LOG_LEVEL_INFO
    Log info messages.

  • dashjs.Debug.LOG_LEVEL_DEBUG
    Log debug messages.
dispatchEvent boolean <optional>
 false

Enable to trigger a Events.LOG event whenever log output is generated.

Note this will be dispatched regardless of log level.
Source:

ErrorSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
recoverAttempts object <optional>
 {mediaErrorDecode: 5}

Defines the maximum number of recover attempts for specific media errors.

For mediaErrorDecode the player will reset the MSE and skip the blacklisted segment that caused the decode error. The resulting gap will be handled by the GapController.
Source:

Gaps

Type:
  • Object
Properties:
Name Type Argument Default Description
jumpGaps boolean <optional>
 true

Sets whether player should jump small gaps (discontinuities) in the buffer.
jumpLargeGaps boolean <optional>
 true

Sets whether player should jump large gaps (discontinuities) in the buffer.
smallGapLimit number <optional>
 1.5

Time in seconds for a gap to be considered small.
threshold number <optional>
 0.3

Threshold at which the gap handling is executed. If currentRangeEnd - currentTime < threshold the gap jump will be triggered.
For live stream the jump might be delayed to keep a consistent live edge.
Note that the amount of buffer at which platforms automatically stall might differ.
enableSeekFix boolean <optional>
 true

Enables the adjustment of the seek target once no valid segment request could be generated for a specific seek time. This can happen if the user seeks to a position for which there is a gap in the timeline.
enableStallFix boolean <optional>
 false

If playback stalled in a buffered range this fix will perform a seek by the value defined in stallSeek to trigger playback again.
stallSeek number <optional>
 0.1

Value to be used in case enableStallFix is set to true
Source:

LiveCatchupSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
maxDrift number <optional>
 NaN

Use this method to set the maximum latency deviation allowed before dash.js to do a seeking to live position.

In low latency mode, when the difference between the measured latency and the target one, as an absolute number, is higher than the one sets with this method, then dash.js does a seek to live edge position minus the target live delay.

LowLatencyMaxDriftBeforeSeeking should be provided in seconds.

If 0, then seeking operations won't be used for fixing latency deviations.

Note: Catch-up mechanism is only applied when playing low latency live streams.
playbackRate number <optional>
 {min: NaN, max: NaN}

Use this parameter to set the minimum and maximum catch up rates, as percentages, for low latency live streams.

In low latency mode, when measured latency is higher/lower than the target one, dash.js increases/decreases playback rate respectively up to (+/-) the percentage defined with this method until target is reached.

Valid values for min catch up rate are in the range -0.5 to 0 (-50% to 0% playback rate decrease)

Valid values for max catch up rate are in the range 0 to 1 (0% to 100% playback rate increase).

Set min and max to NaN to turn off live catch up feature.

These playback rate limits take precedence over any PlaybackRate values in ServiceDescription elements in an MPD. If only one of the min/max properties is given a value, the property without a value will not fall back to a ServiceDescription value. Its default value of NaN will be used.

Note: Catch-up mechanism is only applied when playing low latency live streams.
playbackBufferMin number <optional>
 0.5

Use this parameter to specify the minimum buffer which is used for LoL+ based playback rate reduction.
enabled boolean <optional>
 null

Use this parameter to enable the catchup mode for non low-latency streams.
mode string <optional>
 "liveCatchupModeDefault"

Use this parameter to switch between different catchup modes.

Options: "liveCatchupModeDefault" or "liveCatchupModeLOLP".

Note: Catch-up mechanism is automatically applied when playing low latency live streams.
Source:

LiveDelay

Type:
  • Object
Properties:
Name Type Argument Default Description
liveDelayFragmentCount number <optional>
 NaN

Changing this value will lower or increase live stream latency.

The detected segment duration will be multiplied by this value to define a time in seconds to delay a live stream from the live edge.

Lowering this value will lower latency but may decrease the player's ability to build a stable buffer.
liveDelay number <optional>
 NaN

Equivalent in seconds of setLiveDelayFragmentCount.

Lowering this value will lower latency but may decrease the player's ability to build a stable buffer.

This value should be less than the manifest duration by a couple of segment durations to avoid playback issues.

If set, this parameter will take precedence over setLiveDelayFragmentCount and manifest info.
useSuggestedPresentationDelay boolean <optional>
 true

Set to true if you would like to overwrite the default live delay and honor the SuggestedPresentationDelay attribute in by the manifest.
Source:

Metrics

Type:
  • Object
Properties:
Name Type Argument Default Description
metricsMaxListDepth number <optional>
 100

Maximum number of metrics that are persisted per type.
Source:

PlayerSettings

Type:
  • Object
Properties:
Name Type Argument Description
debug module:Settings~DebugSettings <optional>

Debug related settings.
errors module:Settings~ErrorSettings <optional>

Error related settings
streaming module:Settings~StreamingSettings <optional>

Streaming related settings.
Source:
Example
// Full settings object
settings = {
       debug: {
           logLevel: Debug.LOG_LEVEL_WARNING,
           dispatchEvent: false
       },
       streaming: {
           abandonLoadTimeout: 10000,
           wallclockTimeUpdateInterval: 100,
           manifestUpdateRetryInterval: 100,
           cacheInitSegments: false,
           applyServiceDescription: true,
           applyProducerReferenceTime: true,
           applyContentSteering: true,
           eventControllerRefreshDelay: 100,
           enableManifestDurationMismatchFix: true,
           enableManifestTimescaleMismatchFix: false,
           parseInbandPrft: false,
           capabilities: {
              filterUnsupportedEssentialProperties: true,
              useMediaCapabilitiesApi: false
           },
           timeShiftBuffer: {
               calcFromSegmentTimeline: false,
               fallbackToSegmentTimeline: true
           },
           metrics: {
             maxListDepth: 100
           },
           delay: {
               liveDelayFragmentCount: NaN,
               liveDelay: NaN,
               useSuggestedPresentationDelay: true
           },
           protection: {
               keepProtectionMediaKeys: false,
               ignoreEmeEncryptedEvent: false,
               detectPlayreadyMessageFormat: true,
           },
           buffer: {
               enableSeekDecorrelationFix: false,
               fastSwitchEnabled: true,
               flushBufferAtTrackSwitch: false,
               reuseExistingSourceBuffers: true,
               bufferPruningInterval: 10,
               bufferToKeep: 20,
               bufferTimeAtTopQuality: 30,
               bufferTimeAtTopQualityLongForm: 60,
               initialBufferLevel: NaN,
               stableBufferTime: 12,
               longFormContentDurationThreshold: 600,
               stallThreshold: 0.3,
               useAppendWindow: true,
               setStallState: true,
               avoidCurrentTimeRangePruning: false,
               useChangeTypeForTrackSwitch: true,
               mediaSourceDurationInfinity: true,
               resetSourceBuffersForTrackSwitch: false
           },
           gaps: {
               jumpGaps: true,
               jumpLargeGaps: true,
               smallGapLimit: 1.5,
               threshold: 0.3,
               enableSeekFix: true,
               enableStallFix: false,
               stallSeek: 0.1
           },
           utcSynchronization: {
               enabled: true,
               useManifestDateHeaderTimeSource: true,
               backgroundAttempts: 2,
               timeBetweenSyncAttempts: 30,
               maximumTimeBetweenSyncAttempts: 600,
               minimumTimeBetweenSyncAttempts: 2,
               timeBetweenSyncAttemptsAdjustmentFactor: 2,
               maximumAllowedDrift: 100,
               enableBackgroundSyncAfterSegmentDownloadError: true,
               defaultTimingSource: {
                   scheme: 'urn:mpeg:dash:utc:http-xsdate:2014',
                   value: 'http://time.akamai.com/?iso&ms'
               }
           },
           scheduling: {
               defaultTimeout: 500,
               lowLatencyTimeout: 0,
               scheduleWhilePaused: true
           },
           text: {
               defaultEnabled: true,
               extendSegmentedCues: true,
               webvtt: {
                   customRenderingEnabled: false
               }
           },
           liveCatchup: {
               maxDrift: NaN,
               playbackRate: {min: NaN, max: NaN},
               playbackBufferMin: 0.5,
               enabled: null,
               mode: Constants.LIVE_CATCHUP_MODE_DEFAULT
           },
           lastBitrateCachingInfo: { enabled: true, ttl: 360000 },
           lastMediaSettingsCachingInfo: { enabled: true, ttl: 360000 },
           saveLastMediaSettingsForCurrentStreamingSession: true,
           cacheLoadThresholds: { video: 50, audio: 5 },
           trackSwitchMode: {
               audio: Constants.TRACK_SWITCH_MODE_ALWAYS_REPLACE,
               video: Constants.TRACK_SWITCH_MODE_NEVER_REPLACE
           },
           selectionModeForInitialTrack: Constants.TRACK_SELECTION_MODE_HIGHEST_SELECTION_PRIORITY,
           fragmentRequestTimeout: 20000,
           fragmentRequestProgressTimeout: -1,
           manifestRequestTimeout: 10000,
           retryIntervals: {
               [HTTPRequest.MPD_TYPE]: 500,
               [HTTPRequest.XLINK_EXPANSION_TYPE]: 500,
               [HTTPRequest.MEDIA_SEGMENT_TYPE]: 1000,
               [HTTPRequest.INIT_SEGMENT_TYPE]: 1000,
               [HTTPRequest.BITSTREAM_SWITCHING_SEGMENT_TYPE]: 1000,
               [HTTPRequest.INDEX_SEGMENT_TYPE]: 1000,
               [HTTPRequest.MSS_FRAGMENT_INFO_SEGMENT_TYPE]: 1000,
               [HTTPRequest.LICENSE]: 1000,
               [HTTPRequest.OTHER_TYPE]: 1000,
               lowLatencyReductionFactor: 10
           },
           retryAttempts: {
               [HTTPRequest.MPD_TYPE]: 3,
               [HTTPRequest.XLINK_EXPANSION_TYPE]: 1,
               [HTTPRequest.MEDIA_SEGMENT_TYPE]: 3,
               [HTTPRequest.INIT_SEGMENT_TYPE]: 3,
               [HTTPRequest.BITSTREAM_SWITCHING_SEGMENT_TYPE]: 3,
               [HTTPRequest.INDEX_SEGMENT_TYPE]: 3,
               [HTTPRequest.MSS_FRAGMENT_INFO_SEGMENT_TYPE]: 3,
               [HTTPRequest.LICENSE]: 3,
               [HTTPRequest.OTHER_TYPE]: 3,
               lowLatencyMultiplyFactor: 5
           },
           abr: {
               movingAverageMethod: Constants.MOVING_AVERAGE_SLIDING_WINDOW,
               ABRStrategy: Constants.ABR_STRATEGY_DYNAMIC,
               additionalAbrRules: {
                  insufficientBufferRule: true,
                  switchHistoryRule: true,
                  droppedFramesRule: true,
                  abandonRequestsRule: true
               },
               bandwidthSafetyFactor: 0.9,
               useDefaultABRRules: true,
               useDeadTimeLatency: true,
               limitBitrateByPortal: false,
               usePixelRatioInLimitBitrateByPortal: false,
               maxBitrate: { audio: -1, video: -1 },
               minBitrate: { audio: -1, video: -1 },
               maxRepresentationRatio: { audio: 1, video: 1 },
               initialBitrate: { audio: -1, video: -1 },
               initialRepresentationRatio: { audio: -1, video: -1 },
               autoSwitchBitrate: { audio: true, video: true },
               fetchThroughputCalculationMode: Constants.ABR_FETCH_THROUGHPUT_CALCULATION_DOWNLOADED_DATA
           },
           cmcd: {
               enabled: false,
               sid: null,
               cid: null,
               rtp: null,
               rtpSafetyFactor: 5,
               mode: Constants.CMCD_MODE_QUERY,
               enabledKeys: ['br', 'd', 'ot', 'tb' , 'bl', 'dl', 'mtp', 'nor', 'nrr', 'su' , 'bs', 'rtp' , 'cid', 'pr', 'sf', 'sid', 'st', 'v']
           },
           cmsd: {
               enabled: false,
               abr: {
                   applyMb: false,
                   etpWeightRatio: 0
               }
          }
         },
         errors: {
           recoverAttempts: {
               mediaErrorDecode: 5
            }
         }
}

Protection

Type:
  • Object
Properties:
Name Type Argument Default Description
keepProtectionMediaKeys boolean <optional>
 false

Set the value for the ProtectionController and MediaKeys life cycle.

If true, the ProtectionController and then created MediaKeys and MediaKeySessions will be preserved during the MediaPlayer lifetime.
ignoreEmeEncryptedEvent boolean <optional>
 false

If set to true the player will ignore "encrypted" and "needkey" events thrown by the EME.
detectPlayreadyMessageFormat boolean <optional>
 true

If set to true the player will use the raw unwrapped message from the Playready CDM
Source:

RequestTypeSettings

Type:
  • Object
Properties:
Name Type Argument Description
MPD number <optional>

Manifest type of requests.
XLinkExpansion number <optional>

XLink expansion type of requests.
InitializationSegment number <optional>

Request to retrieve an initialization segment.
IndexSegment number <optional>

Request to retrieve an index segment (SegmentBase).
MediaSegment number <optional>

Request to retrieve a media segment (video/audio/image/text chunk).
BitstreamSwitchingSegment number <optional>

Bitrate stream switching type of request.
FragmentInfoSegment number <optional>

Request to retrieve a FragmentInfo segment (specific to Smooth Streaming live streams).
other number <optional>

Other type of request.
lowLatencyReductionFactor number <optional>

For low latency mode, values of type of request are divided by lowLatencyReductionFactor.

Note: It's not type of request.
lowLatencyMultiplyFactor number <optional>

For low latency mode, values of type of request are multiplied by lowLatencyMultiplyFactor.

Note: It's not type of request.
Source:

Scheduling

Type:
  • Object
Properties:
Name Type Argument Default Description
defaultTimeout number <optional>
 500

Default timeout between two consecutive segment scheduling attempts
lowLatencyTimeout number <optional>
 0

Default timeout between two consecutive low-latency segment scheduling attempts
scheduleWhilePaused boolean <optional>
 true

Set to true if you would like dash.js to keep downloading fragments in the background when the video element is paused.
Source:

StreamingSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
abandonLoadTimeout number <optional>
 10000

A timeout value in seconds, which during the ABRController will block switch-up events.

This will only take effect after an abandoned fragment event occurs.
wallclockTimeUpdateInterval number <optional>
 100

How frequently the wallclockTimeUpdated internal event is triggered (in milliseconds).
manifestUpdateRetryInterval number <optional>
 100

For live streams, set the interval-frequency in milliseconds at which dash.js will check if the current manifest is still processed before downloading the next manifest once the minimumUpdatePeriod time has.
cacheInitSegments boolean <optional>
 false

Enables the caching of init segments to avoid requesting the init segments before each representation switch.
applyServiceDescription boolean <optional>
 true

Set to true if dash.js should use the parameters defined in ServiceDescription elements
applyProducerReferenceTime boolean <optional>
 true

Set to true if dash.js should use the parameters defined in ProducerReferenceTime elements in combination with ServiceDescription elements.
applyContentSteering boolean <optional>
 true

Set to true if dash.js should apply content steering during playback.
eventControllerRefreshDelay number <optional>
 100

For multi-period streams, overwrite the manifest mediaPresentationDuration attribute with the sum of period durations if the manifest mediaPresentationDuration is greater than the sum of period durations
enableManifestDurationMismatchFix boolean <optional>
 true

Overwrite the manifest segments base information timescale attributes with the timescale set in initialization segments
enableManifestTimescaleMismatchFix boolean <optional>
 false

Defines the delay in milliseconds between two consecutive checks for events to be fired.
parseInbandPrft boolean <optional>
 false

Set to true if dash.js should parse inband prft boxes (ProducerReferenceTime) and trigger events.
metrics module:Settings~Metrics

Metric settings
delay module:Settings~LiveDelay

Live Delay settings
timeShiftBuffer module:Settings~TimeShiftBuffer

TimeShiftBuffer settings
protection module:Settings~Protection

DRM related settings
capabilities module:Settings~Capabilities

Capability related settings
buffer module:Settings~Buffer

Buffer related settings
gaps module:Settings~Gaps

Gap related settings
utcSynchronization module:Settings~UtcSynchronizationSettings

Settings related to UTC clock synchronization
scheduling module:Settings~Scheduling

Settings related to segment scheduling
text module:Settings~Text

Settings related to Subtitles and captions
liveCatchup module:Settings~LiveCatchupSettings

Settings related to live catchup.
lastBitrateCachingInfo module:Settings~CachingInfoSettings <optional>
 {enabled: true, ttl: 360000}

Set to false if you would like to disable the last known bit rate from being stored during playback and used to set the initial bit rate for subsequent playback within the expiration window.

The default expiration is one hour, defined in milliseconds.

If expired, the default initial bit rate (closest to 1000 kbps) will be used for that session and a new bit rate will be stored during that session.
lastMediaSettingsCachingInfo module:Settings~CachingInfoSettings <optional>
 {enabled: true, ttl: 360000}

Set to false if you would like to disable the last media settings from being stored to localStorage during playback and used to set the initial track for subsequent playback within the expiration window.

The default expiration is one hour, defined in milliseconds.
saveLastMediaSettingsForCurrentStreamingSession boolean <optional>
 true

Set to true if dash.js should save media settings from last selected track for incoming track selection during current streaming session.
cacheLoadThresholds module:Settings~AudioVideoSettings <optional>
 {video: 50, audio: 5}

For a given media type, the threshold which defines if the response to a fragment request is coming from browser cache or not.
trackSwitchMode module:Settings~AudioVideoSettings <optional>
 {video: "neverReplace", audio: "alwaysReplace"}

For a given media type defines if existing segments in the buffer should be overwritten once the track is switched. For instance if the user switches the audio language the existing segments in the audio buffer will be replaced when setting this value to "alwaysReplace".

Possible values

  • Constants.TRACK_SWITCH_MODE_ALWAYS_REPLACE
    Replace existing segments in the buffer

  • Constants.TRACK_SWITCH_MODE_NEVER_REPLACE
    Do not replace existing segments in the buffer
selectionModeForInitialTrack string <optional>
 "highestSelectionPriority"

Sets the selection mode for the initial track. This mode defines how the initial track will be selected if no initial media settings are set. If initial media settings are set this parameter will be ignored. Available options are:

Possible values

  • Constants.TRACK_SELECTION_MODE_HIGHEST_SELECTION_PRIORITY
    This mode makes the player select the track with the highest selectionPriority as defined in the manifest. If not selectionPriority is given we fallback to TRACK_SELECTION_MODE_HIGHEST_BITRATE. This mode is a default mode.

  • Constants.TRACK_SELECTION_MODE_HIGHEST_BITRATE
    This mode makes the player select the track with a highest bitrate.

  • Constants.TRACK_SELECTION_MODE_FIRST_TRACK
    This mode makes the player select the first track found in the manifest.

  • Constants.TRACK_SELECTION_MODE_HIGHEST_EFFICIENCY
    This mode makes the player select the track with the lowest bitrate per pixel average.

  • Constants.TRACK_SELECTION_MODE_WIDEST_RANGE
    This mode makes the player select the track with a widest range of bitrates.
fragmentRequestTimeout number <optional>
 20000

Time in milliseconds before timing out on loading a media fragment.
fragmentRequestProgressTimeout number <optional>
 -1

Time in milliseconds before timing out on loading progress of a media fragment.
manifestRequestTimeout number <optional>
 10000

Time in milliseconds before timing out on loading a manifest.

Fragments that timeout are retried as if they failed.
retryIntervals module:Settings~RequestTypeSettings <optional>

Time in milliseconds of which to reload a failed file load attempt.

For low latency mode these values are divided by lowLatencyReductionFactor.
retryAttempts module:Settings~RequestTypeSettings <optional>

Total number of retry attempts that will occur on a file load before it fails.

For low latency mode these values are multiplied by lowLatencyMultiplyFactor.
abr module:Settings~AbrSettings

Adaptive Bitrate algorithm related settings.
cmcd module:Settings~CmcdSettings

Settings related to Common Media Client Data reporting.
cmsd module:Settings~CmsdSettings

Settings related to Common Media Server Data parsing.
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Text

Type:
  • Object
Properties:
Name Type Argument Default Description
defaultEnabled boolean <optional>
 true

Enable/disable subtitle rendering by default.
extendSegmentedCues boolean <optional>
 true

Enable/disable patching of segmented cues in order to merge as a single cue by extending cue end time.
webvtt object <optional>
 {customRenderingEnabled=false}

Enables the custom rendering for WebVTT captions. For details refer to the "Subtitles and Captions" sample section of dash.js.
Custom WebVTT rendering requires the external library vtt.js that can be found in the contrib folder.
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TimeShiftBuffer

Type:
  • Object
Properties:
Name Type Argument Default Description
calcFromSegmentTimeline boolean <optional>
 false

Enable calculation of the DVR window for SegmentTimeline manifests based on the entries in <SegmentTimeline>.

  • @property {boolean} [fallbackToSegmentTimeline=true]
    In case the MPD uses <SegmentTimeline\ and no segment is found within the DVR window the DVR window is calculated based on the entries in <SegmentTimeline>.
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UtcSynchronizationSettings

Type:
  • Object
Properties:
Name Type Argument Default Description
enabled boolean <optional>
 true

Enables or disables the UTC clock synchronization
useManifestDateHeaderTimeSource boolean <optional>
 true

Allows you to enable the use of the Date Header, if exposed with CORS, as a timing source for live edge detection.

The use of the date header will happen only after the other timing source that take precedence fail or are omitted as described.
backgroundAttempts number <optional>
 2

Number of synchronization attempts to perform in the background after an initial synchronization request has been done. This is used to verify that the derived client-server offset is correct.

The background requests are async and done in parallel to the start of the playback.

This value is also used to perform a resync after 404 errors on segments.
timeBetweenSyncAttempts number <optional>
 30

The time in seconds between two consecutive sync attempts.

Note: This value is used as an initial starting value. The internal value of the TimeSyncController is adjusted during playback based on the drift between two consecutive synchronization attempts.

Note: A sync is only performed after an MPD update. In case the @minimumUpdatePeriod is larger than this value the sync will be delayed until the next MPD update.
maximumTimeBetweenSyncAttempts number <optional>
 600

The maximum time in seconds between two consecutive sync attempts.
minimumTimeBetweenSyncAttempts number <optional>
 2

The minimum time in seconds between two consecutive sync attempts.
timeBetweenSyncAttemptsAdjustmentFactor number <optional>
 2

The factor used to multiply or divide the timeBetweenSyncAttempts parameter after a sync. The maximumAllowedDrift defines whether this value is used as a factor or a dividend.
maximumAllowedDrift number <optional>
 100

The maximum allowed drift specified in milliseconds between two consecutive synchronization attempts.
enableBackgroundSyncAfterSegmentDownloadError boolean <optional>
 true

Enables or disables the background sync after the player ran into a segment download error.
defaultTimingSource object <optional>
 {scheme:'urn:mpeg:dash:utc:http-xsdate:2014',value: 'http://time.akamai.com/?iso&ms'}

The default timing source to be used. The timing sources in the MPD take precedence over this one.
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