Class: shaka.util.PeriodCombiner

Constructor

new PeriodCombiner()

Implements:
Source:

Members

BetterOrWorse :number

Type:
  • number
Properties:
Name Value Type Description
BETTER 1 number
EQUAL 0 number
WORSE -1 number
Source:

audioStreams_ :Array.<shaka.extern.Stream>

Type:
Source:

imageStreams_ :Array.<shaka.extern.Stream>

Type:
Source:

textStreams_ :Array.<shaka.extern.Stream>

Type:
Source:

usedPeriodIds_ :Set.<string>

The IDs of the periods we have already used to generate streams. This helps us identify the periods which have been added when a live stream is updated.
Type:
  • Set.<string>
Source:

variants_ :Array.<shaka.extern.Variant>

Type:
Source:

videoStreams_ :Array.<shaka.extern.Stream>

Type:
Source:

Methods

areAVStreamsCompatible_(outputStream, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T An audio or video output stream
candidate T A candidate stream to be combined with the output
Source:
Returns:
True if the candidate could be combined with the output stream
Type
boolean

areImageStreamsCompatible_(outputStream, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T A image output stream
candidate T A candidate stream to be combined with the output
Source:
Returns:
True if the candidate could be combined with the output
Type
boolean

areTextStreamsCompatible_(outputStream, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T A text output stream
candidate T A candidate stream to be combined with the output
Source:
Returns:
True if the candidate could be combined with the output
Type
boolean

cloneStream_(stream) → {shaka.extern.Stream}

Clone a Stream to make an output Stream for combining others across periods.
Parameters:
Name Type Description
stream shaka.extern.Stream
Source:
Returns:
Type
shaka.extern.Stream

cloneStreamDB_(streamDb) → {shaka.extern.StreamDB}

Clone a StreamDB to make an output stream for combining others across periods.
Parameters:
Name Type Description
streamDb shaka.extern.StreamDB
Source:
Returns:
Type
shaka.extern.StreamDB

combine_(outputStreamsnon-null, streamsPerPeriodnon-null, firstNewPeriodIndex, clone, concat) → {Promise.<!Array.<T>>}

Combine input Streams per period into flat output Streams. Templatized to handle both DASH Streams and offline StreamDBs.
Parameters:
Name Type Description
outputStreams Array.<T> A list of existing output streams, to facilitate updates for live DASH content. Will be modified and returned.
streamsPerPeriod Array.<!Array.<T>> A list of lists of Streams from each period.
firstNewPeriodIndex number An index into streamsPerPeriod which represents the first new period that hasn't been processed yet.
clone function(T):T Make a clone of an input stream.
concat function(T, T) Concatenate the second stream onto the end of the first.
Source:
Returns:
The same array passed to outputStreams, modified to include any newly-created streams.
Type
Promise.<!Array.<T>>

combineDbStreams(streamDbsPerPeriodnon-null) → {Promise.<!Array.<shaka.extern.StreamDB>>}

Stitch together DB streams across periods, taking a mix of stream types. The offline database does not separate these by type. Unlike the DASH case, this does not need to maintain any state for manifest updates.
Parameters:
Name Type Description
streamDbsPerPeriod Array.<!Array.<shaka.extern.StreamDB>>
Source:
Returns:
Type
Promise.<!Array.<shaka.extern.StreamDB>>

compareClosestPreferLower(outputValue, bestValue, candidateValue) → {shaka.util.PeriodCombiner.BetterOrWorse}

Compare the best value so far with the candidate value and the output value. Decide if the candidate is better, equal, or worse than the best so far. Any value less than or equal to the output is preferred over a larger value, and closer to the output is better than farther. This provides us a generic way to choose things that should match as closely as possible, like resolution, frame rate, audio channels, or sample rate. If we have to go higher to make a match, we will. But if the user selects 480p, for example, we don't want to surprise them with 720p and waste bandwidth if there's another choice available to us.
Parameters:
Name Type Description
outputValue number
bestValue number
candidateValue number
Source:
Returns:
Type
shaka.util.PeriodCombiner.BetterOrWorse

compareClosestPreferMinimalAbsDiff_(outputValue, bestValue, candidateValue) → {shaka.util.PeriodCombiner.BetterOrWorse}

Parameters:
Name Type Description
outputValue number
bestValue number
candidateValue number
Source:
Returns:
Type
shaka.util.PeriodCombiner.BetterOrWorse

concatenateStreamDBs_(output, input)

Combine the various fields of the input StreamDB into the output.
Parameters:
Name Type Description
output shaka.extern.StreamDB
input shaka.extern.StreamDB
Source:

concatenateStreams_(output, input)

Combine the various fields of the input Stream into the output.
Parameters:
Name Type Description
output shaka.extern.Stream
input shaka.extern.Stream
Source:

createNewOutputStream_(stream, streamsPerPeriodnon-null, clone, concat, unusedStreamsPerPeriodnon-null) → {Promise.<?T>}

Create a new output Stream based on a particular input Stream. Locates matching Streams in all other periods and combines them into an output Stream. Templatized to handle both DASH Streams and offline StreamDBs.
Parameters:
Name Type Description
stream T An input stream on which to base the output stream.
streamsPerPeriod Array.<!Array.<T>> A list of lists of Streams from each period.
clone function(T):T Make a clone of an input stream.
concat function(T, T) Concatenate the second stream onto the end of the first.
unusedStreamsPerPeriod Array.<!Set.<T>> An array of sets of unused streams from each period.
Source:
Returns:
A newly-created output Stream, or null if matches could not be found.`
Type
Promise.<?T>

createSegmentIndexes_(streamsnon-null) → {Promise}

Creates all segment indexes for an array of streams. Returns once every segment index is created.
Parameters:
Name Type Description
streams Array.<!shaka.extern.Stream>
Source:
Returns:
Type
Promise

dummyStream_(type) → {shaka.extern.Stream}

Create a dummy Stream to fill in periods that are missing a certain type, to avoid failing the general flattening algorithm. This won't be used for audio or video, since those are strictly required in all periods if they exist in any period.
Parameters:
Name Type Description
type shaka.util.ManifestParserUtils.ContentType
Source:
Returns:
Type
shaka.extern.Stream

dummyStreamDB_(type) → {shaka.extern.StreamDB}

Create a dummy StreamDB to fill in periods that are missing a certain type, to avoid failing the general flattening algorithm. This won't be used for audio or video, since those are strictly required in all periods if they exist in any period.
Parameters:
Name Type Description
type shaka.util.ManifestParserUtils.ContentType
Source:
Returns:
Type
shaka.extern.StreamDB

extendExistingOutputStream_(outputStream, streamsPerPeriodnon-null, firstNewPeriodIndex, concat, unusedStreamsPerPeriodnon-null) → {Promise.<boolean>}

Parameters:
Name Type Description
outputStream T An existing output stream which needs to be extended into new periods.
streamsPerPeriod Array.<!Array.<T>> A list of lists of Streams from each period.
firstNewPeriodIndex number An index into streamsPerPeriod which represents the first new period that hasn't been processed yet.
concat function(T, T) Concatenate the second stream onto the end of the first.
unusedStreamsPerPeriod Array.<!Set.<T>> An array of sets of unused streams from each period.
Source:
Returns:
Type
Promise.<boolean>

extendOutputStream_(outputStream, matchesnon-null, firstNewPeriodIndex, concat, unusedStreamsPerPeriodnon-null)

Parameters:
Name Type Description
outputStream T An existing output stream which needs to be extended into new periods.
matches Array.<T> A list of matching Streams from each period.
firstNewPeriodIndex number An index into streamsPerPeriod which represents the first new period that hasn't been processed yet.
concat function(T, T) Concatenate the second stream onto the end of the first.
unusedStreamsPerPeriod Array.<!Set.<T>> An array of sets of unused streams from each period.
Source:

filterOutAudioStreamDuplicates_(periodsnon-null)

Parameters:
Name Type Description
periods Array.<shaka.util.PeriodCombiner.Period>
Source:

filterOutImageStreamDuplicates_(periodsnon-null)

Parameters:
Name Type Description
periods Array.<shaka.util.PeriodCombiner.Period>
Source:

filterOutTextStreamDuplicates_(periodsnon-null)

Parameters:
Name Type Description
periods Array.<shaka.util.PeriodCombiner.Period>
Source:

filterOutVideoStreamDuplicates_(periodsnon-null)

Parameters:
Name Type Description
periods Array.<shaka.util.PeriodCombiner.Period>
Source:

findBestMatchInPeriod_(streamsnon-null, outputStream) → {T}

Find the best match for the output stream.
Parameters:
Name Type Description
streams Array.<T>
outputStream T
Source:
Returns:
Returns null if no match can be found.
Type
T

findMatchesInAllPeriods_(streamsPerPeriodnon-null, outputStream) → {Array.<T>}

Finds streams in all periods which match the output stream.
Parameters:
Name Type Description
streamsPerPeriod Array.<!Array.<T>>
outputStream T
Source:
Returns:
Type
Array.<T>

isAudioStreamBetterMatch_(outputStream, best, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T An audio output stream
best T The best match so far for this period
candidate T A candidate stream which might be better
Source:
Returns:
True if the candidate is a better match
Type
boolean

isImageStreamBetterMatch_(outputStream, best, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T A image output stream
best T The best match so far for this period
candidate T A candidate stream which might be better
Source:
Returns:
True if the candidate is a better match
Type
boolean

isTextStreamBetterMatch_(outputStream, best, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T A text output stream
best T The best match so far for this period
candidate T A candidate stream which might be better
Source:
Returns:
True if the candidate is a better match
Type
boolean

isVideoStreamBetterMatch_(outputStream, best, candidate) → {boolean}

Parameters:
Name Type Description
outputStream T A video output stream
best T The best match so far for this period
candidate T A candidate stream which might be better
Source:
Returns:
True if the candidate is a better match
Type
boolean

combinePeriods(periodsnon-null, isDynamic) → {Promise}

Parameters:
Name Type Description
periods Array.<shaka.util.PeriodCombiner.Period>
isDynamic boolean
Source:
Returns:
Type
Promise

getImageStreams() → {Array.<shaka.extern.Stream>}

Source:
Returns:
Type
Array.<shaka.extern.Stream>

getTextStreams() → {Array.<shaka.extern.Stream>}

Source:
Returns:
Type
Array.<shaka.extern.Stream>

getVariants() → {Array.<shaka.extern.Variant>}

Source:
Returns:
Type
Array.<shaka.extern.Variant>

release()

Request that this object release all internal references.
Implements:
Source:

Type Definitions

Period

Contains the streams from one DASH period.
Type:
Properties:
Name Type Description
id string The Period ID.
audioStreams Array.<shaka.extern.Stream> The audio streams from one Period.
videoStreams Array.<shaka.extern.Stream> The video streams from one Period.
textStreams Array.<shaka.extern.Stream> The text streams from one Period.
imageStreams Array.<shaka.extern.Stream> The image streams from one Period.
Source: