Class: shaka.media.MediaSourceEngine

Constructor

new MediaSourceEngine(video, mediaSource, textTrack)

MediaSourceEngine wraps all operations on MediaSource and SourceBuffers. All asynchronous operations return a Promise, and all operations are internally synchronized and serialized as needed. Operations that can be done in parallel will be done in parallel.
Parameters:
Name Type Description
video HTMLMediaElement The video element, used to read error codes when MediaSource operations fail.
mediaSource MediaSource The MediaSource, which must be in the 'open' state.
textTrack TextTrack The TextTrack to use for subtitles/captions.
Implements:
Source:

Members

(private) destroyed_ :boolean

Type:
  • boolean
Source:

(private) eventManager_ :shaka.util.EventManager

Type:
Source:

(private) mediaSource_ :MediaSource

Type:
  • MediaSource
Source:

(private, non-null) queues_ :Object.<string, !Array.<shaka.media.MediaSourceEngine.Operation>>

Type:
Source:

(private, non-null) sourceBuffers_ :Object.<string, SourceBuffer>

Type:
  • Object.<string, SourceBuffer>
Source:

(private) textEngine_ :shaka.media.TextEngine

Type:
Source:

(private) textTrack_ :TextTrack

Type:
  • TextTrack
Source:

(private) video_ :HTMLMediaElement

Type:
  • HTMLMediaElement
Source:

Methods

(static) isBrowserSupported() → {boolean}

Returns true if the browser has the basic APIs we need.
Source:
Returns:
Type
boolean

(static) isTypeSupported(mimeType) → {boolean}

Checks if a certain type is supported.
Parameters:
Name Type Description
mimeType string
Source:
Returns:
Type
boolean

(static) probeSupport() → (non-null) {Object.<string, boolean>}

Returns a map of MediaSource support for well-known types.
Source:
Returns:
Type
Object.<string, boolean>

(private) abort_(contentType)

Call abort() on the SourceBuffer. This resets MSE's last_decode_timestamp on all track buffers, which should trigger the splicing logic for overlapping segments.
Parameters:
Name Type Description
contentType string
Source:

(private) append_(contentType, datanon-null)

Append data to the SourceBuffer.
Parameters:
Name Type Description
contentType string
data ArrayBuffer
Source:
Throws:
QuotaExceededError if the browser's buffer is full

appendBuffer(contentType, datanon-null, startTimenullable, endTimenullable) → (non-null) {Promise}

Enqueue an operation to append data to the SourceBuffer. Start and end times are needed for TextEngine, but not for MediaSource. Start and end times may be null for initialization segments, if present they are relative to the presentation timeline.
Parameters:
Name Type Attributes Description
contentType string
data ArrayBuffer
startTime number <nullable>
endTime number <nullable>
Source:
Returns:
Type
Promise

bufferedAheadOf(contentType, time, opt_toleranceopt) → {number}

Computes how far ahead of the given timestamp is buffered for the given content type.
Parameters:
Name Type Attributes Description
contentType string
time number
opt_tolerance number <optional>
 An optional tolerance for range start times. Counts a range starting anywhere from time to time + opt_tolerance.
Source:
Returns:
The amount of time buffered ahead in seconds.
Type
number

bufferEnd(contentType) → (nullable) {number}

Gets the last timestamp in buffer for the given content type.
Parameters:
Name Type Description
contentType string
Source:
Returns:
The timestamp in seconds, or null if nothing is buffered.
Type
number

bufferStart(contentType) → (nullable) {number}

Gets the first timestamp in buffer for the given content type.
Parameters:
Name Type Description
contentType string
Source:
Returns:
The timestamp in seconds, or null if nothing is buffered.
Type
number

clear(contentType) → (non-null) {Promise}

Enqueue an operation to clear the SourceBuffer.
Parameters:
Name Type Description
contentType string
Source:
Returns:
Type
Promise

destroy() → (non-null) {Promise}

Destroys the object, releasing all resources and shutting down all operations. Returns a Promise which is resolved when destruction is complete. This Promise should never be rejected.
Implements:
Source:
Returns:
Type
Promise

endOfStream(opt_reasonopt) → (non-null) {Promise}

Parameters:
Name Type Attributes Description
opt_reason string <optional>
 Valid reasons are 'network' and 'decode'.
Source:
See:
Returns:
Type
Promise

(private) enqueueBlockingOperation_(run) → (non-null) {Promise}

Enqueue an operation which must block all other operations on all SourceBuffers.
Parameters:
Name Type Description
run function()
Source:
Returns:
Type
Promise

(private) enqueueOperation_(contentType, start) → (non-null) {Promise}

Enqueue an operation and start it if appropriate.
Parameters:
Name Type Description
contentType string
start function()
Source:
Returns:
Type
Promise

flush(contentType) → (non-null) {Promise}

Enqueue an operation to flush the SourceBuffer. This is a workaround for what we believe is a Chromecast bug.
Parameters:
Name Type Description
contentType string
Source:
Returns:
Type
Promise

(private) flush_(contentType)

Nudge the playhead to force the media pipeline to be flushed. This seems to be necessary on Chromecast to get new content to replace old content.
Parameters:
Name Type Description
contentType string
Source:

(private) getBuffered_(contentType) → {TimeRanges}

Parameters:
Name Type Description
contentType string
Source:
Returns:
The buffered ranges for the given content type, or null if the buffered ranges could not be obtained.
Type
TimeRanges

getDuration() → {number}

Get the current MediaSource duration.
Source:
Returns:
Type
number

init(typeConfignon-null, useRelativeCueTimestamps)

Parameters:
Name Type Description
typeConfig Object.<string, string> A map of content types to full MIME types. For example: { 'audio': 'audio/webm; codecs="vorbis"', 'video': 'video/webm; codecs="vp9"', 'text': 'text/vtt' }. All types given must be supported.
useRelativeCueTimestamps boolean
Source:
Throws:
  • InvalidAccessError if blank MIME types are given
  • NotSupportedError if unsupported MIME types are given
  • QuotaExceededError if the browser can't support that many buffers

(private) onError_(contentType, eventnon-null)

Parameters:
Name Type Description
contentType string
event Event
Source:

(private) onUpdateEnd_(contentType)

Parameters:
Name Type Description
contentType string
Source:

(private) popFromQueue_(contentType)

Pop from the front of the queue and start a new operation.
Parameters:
Name Type Description
contentType string
Source:

remove(contentType, startTime, endTime) → (non-null) {Promise}

Enqueue an operation to remove data from the SourceBuffer.
Parameters:
Name Type Description
contentType string
startTime number
endTime number
Source:
Returns:
Type
Promise

(private) remove_(contentType, startTime, endTime)

Remove data from the SourceBuffer.
Parameters:
Name Type Description
contentType string
startTime number
endTime number
Source:

setAppendWindowEnd(contentType, appendWindowEnd) → (non-null) {Promise}

Sets the append window end for the given content type.
Parameters:
Name Type Description
contentType string
appendWindowEnd number The timestamp to set the append window end to. Media beyond this value will be truncated.
Source:
Returns:
Type
Promise

(private) setAppendWindowEnd_(contentType, appendWindowEnd)

Set the SourceBuffer's append window end.
Parameters:
Name Type Description
contentType string
appendWindowEnd number
Source:

setDuration(duration) → (non-null) {Promise}

We only support increasing duration at this time. Decreasing duration causes the MSE removal algorithm to run, which results in an 'updateend' event. Supporting this scenario would be complicated, and is not currently needed.
Parameters:
Name Type Description
duration number
Source:
Returns:
Type
Promise

setTimestampOffset(contentType, timestampOffset) → (non-null) {Promise}

Sets the timestamp offset for the given content type.
Parameters:
Name Type Description
contentType string
timestampOffset number The timestamp offset. Segments which start at time t will be inserted at time t + timestampOffset instead. This value does not affect segments which have already been inserted.
Source:
Returns:
Type
Promise

(private) setTimestampOffset_(contentType, timestampOffset)

Set the SourceBuffer's timestamp offset.
Parameters:
Name Type Description
contentType string
timestampOffset number
Source:

Type Definitions

Operation

An operation in queue.

Type:
Properties:
Name Type Description
start function() The function which starts the operation.
p shaka.util.PublicPromise The PublicPromise which is associated with this operation.
Source: