MaskingMediaPeriod (ExoPlayer library)

java.lang.Object
- com.google.android.exoplayer2.source.MaskingMediaPeriod

All Implemented Interfaces:

MediaPeriod, MediaPeriod.Callback, SequenceableLoader, SequenceableLoader.Callback<MediaPeriod>
```
public final class MaskingMediaPeriod
extends Object
implements MediaPeriod, MediaPeriod.Callback
```
Media period that defers calling MediaSource.createPeriod(MediaPeriodId, Allocator, long) on a given source until createPeriod(MediaPeriodId) has been called. This is useful if you need to return a media period immediately but the media source that should create it is not yet available or prepared.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface MaskingMediaPeriod.PrepareListener
Listener for preparation events.
- Nested classes/interfaces inherited from interface com.google.android.exoplayer2.source.MediaPeriod
  MediaPeriod.Callback

Nested Classes
Modifier and Type	Class	Description
`static interface`	`MaskingMediaPeriod.PrepareListener`	Listener for preparation events.

Field Summary

Fields
Modifier and Type Field Description

MediaSource.MediaPeriodId id
The MediaSource.MediaPeriodId used to create the masking media period.

Fields
Modifier and Type	Field	Description
`MediaSource.MediaPeriodId`	`id`	The `MediaSource.MediaPeriodId` used to create the masking media period.

Constructor Summary

Constructors
Constructor	Description
`MaskingMediaPeriod(MediaSource.MediaPeriodId id, Allocator allocator, long preparePositionUs)`	Creates a new masking media period.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`continueLoading(long positionUs)`	Attempts to continue loading.
`void`	`createPeriod(MediaSource.MediaPeriodId id)`	Calls `MediaSource.createPeriod(MediaPeriodId, Allocator, long)` on the wrapped source then prepares it if `prepare(Callback, long)` has been called.
`void`	`discardBuffer(long positionUs, boolean toKeyframe)`	Discards buffered media up to the specified position.
`long`	`getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters)`	Returns the position to which a seek will be performed, given the specified seek position and `SeekParameters`.
`long`	`getBufferedPositionUs()`	Returns an estimate of the position up to which data is buffered for the enabled tracks.
`long`	`getNextLoadPositionUs()`	Returns the next load time, or `C.TIME_END_OF_SOURCE` if loading has finished.
`long`	`getPreparePositionOverrideUs()`	Returns the prepare position override set by `overridePreparePositionUs(long)`.
`long`	`getPreparePositionUs()`	Returns the position at which the masking media period was prepared, in microseconds.
`TrackGroupArray`	`getTrackGroups()`	Returns the `TrackGroup`s exposed by the period.
`boolean`	`isLoading()`	Returns whether the media period is currently loading.
`void`	`maybeThrowPrepareError()`	Throws an error that's preventing the period from becoming prepared.
`void`	`onContinueLoadingRequested(MediaPeriod source)`	Called by the loader to indicate that it wishes for its `SequenceableLoader.continueLoading(long)` method to be called when it can continue to load data.
`void`	`onPrepared(MediaPeriod mediaPeriod)`	Called when preparation completes.
`void`	`overridePreparePositionUs(long preparePositionUs)`	Overrides the default prepare position at which to prepare the media period.
`void`	`prepare(MediaPeriod.Callback callback, long preparePositionUs)`	Prepares this media period asynchronously.
`long`	`readDiscontinuity()`	Attempts to read a discontinuity.
`void`	`reevaluateBuffer(long positionUs)`	Re-evaluates the buffer given the playback position.
`void`	`releasePeriod()`	Releases the period.
`long`	`seekToUs(long positionUs)`	Attempts to seek to the specified position in microseconds.
`long`	`selectTracks(@NullableType ExoTrackSelection[] selections, boolean[] mayRetainStreamFlags, @NullableType SampleStream[] streams, boolean[] streamResetFlags, long positionUs)`	Performs a track selection.
`void`	`setMediaSource(MediaSource mediaSource)`	Sets the `MediaSource` that will create the underlying media period.
`void`	`setPrepareListener(MaskingMediaPeriod.PrepareListener listener)`	Sets a listener for preparation events.

Methods inherited from interface com.google.android.exoplayer2.source.MediaPeriod
getStreamKeys

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - id
```
public final MediaSource.MediaPeriodId id
```
    The MediaSource.MediaPeriodId used to create the masking media period.
- Constructor Detail
  - MaskingMediaPeriod
```
public MaskingMediaPeriod(MediaSource.MediaPeriodId id,
                          Allocator allocator,
                          long preparePositionUs)
```
    Creates a new masking media period. The media source must be set via setMediaSource(MediaSource) before preparation can start.
    
    Parameters:
    
    id - The identifier used to create the masking media period.
    
    allocator - The allocator used to create the media period.
    
    preparePositionUs - The expected start position, in microseconds.
- Method Detail
  - setPrepareListener
```
public void setPrepareListener(MaskingMediaPeriod.PrepareListener listener)
```
    Sets a listener for preparation events.
    
    Parameters:
    
    listener - An listener to be notified of media period preparation events. If a listener is set, maybeThrowPrepareError() will not throw but will instead pass the first preparation error (if any) to the listener.
  - getPreparePositionUs
```
public long getPreparePositionUs()
```
    Returns the position at which the masking media period was prepared, in microseconds.
  - overridePreparePositionUs
```
public void overridePreparePositionUs(long preparePositionUs)
```
    Overrides the default prepare position at which to prepare the media period. This method must be called before createPeriod(MediaPeriodId).
    
    Parameters:
    
    preparePositionUs - The default prepare position to use, in microseconds.
  - getPreparePositionOverrideUs
```
public long getPreparePositionOverrideUs()
```
    Returns the prepare position override set by overridePreparePositionUs(long).
  - setMediaSource
```
public void setMediaSource(MediaSource mediaSource)
```
    Sets the MediaSource that will create the underlying media period.
  - createPeriod
```
public void createPeriod(MediaSource.MediaPeriodId id)
```
    Calls MediaSource.createPeriod(MediaPeriodId, Allocator, long) on the wrapped source then prepares it if prepare(Callback, long) has been called. Call releasePeriod() to release the period.
    
    Parameters:
    
    id - The identifier that should be used to create the media period from the media source.
  - releasePeriod
```
public void releasePeriod()
```
    Releases the period.
  - prepare
```
public void prepare(MediaPeriod.Callback callback,
                    long preparePositionUs)
```
    Description copied from interface: MediaPeriod
    
    Prepares this media period asynchronously.
    callback.onPrepared is called when preparation completes. If preparation fails, MediaPeriod.maybeThrowPrepareError() will throw an IOException.
    If preparation succeeds and results in a source timeline change (e.g. the period duration becoming known), MediaSource.MediaSourceCaller.onSourceInfoRefreshed(MediaSource, Timeline) will be called before callback.onPrepared.
    
    Specified by:
    
    prepare in interface MediaPeriod
    
    Parameters:
    
    callback - Callback to receive updates from this period, including being notified when preparation completes.
    
    preparePositionUs - The expected starting position, in microseconds.
  - maybeThrowPrepareError
```
public void maybeThrowPrepareError()
                            throws IOException
```
    Description copied from interface: MediaPeriod
    
    Throws an error that's preventing the period from becoming prepared. Does nothing if no such error exists.
    This method is only called before the period has completed preparation.
    
    Specified by:
    
    maybeThrowPrepareError in interface MediaPeriod
    
    Throws:
    
    IOException - The underlying error.
  - getTrackGroups
```
public TrackGroupArray getTrackGroups()
```
    Description copied from interface: MediaPeriod
    
    Returns the TrackGroups exposed by the period.
    This method is only called after the period has been prepared.
    
    Specified by:
    
    getTrackGroups in interface MediaPeriod
    
    Returns:
    
    The TrackGroups.
  - selectTracks
```
public long selectTracks(@NullableType ExoTrackSelection[] selections,
                         boolean[] mayRetainStreamFlags,
                         @NullableType SampleStream[] streams,
                         boolean[] streamResetFlags,
                         long positionUs)
```
    Description copied from interface: MediaPeriod
    
    Performs a track selection.
    The call receives track selections for each renderer, mayRetainStreamFlags indicating whether the existing SampleStream can be retained for each selection, and the existing streams themselves. The call will update streams to reflect the provided selections, clearing, setting and replacing entries as required. If an existing sample stream is retained but with the requirement that the consuming renderer be reset, then the corresponding flag in streamResetFlags will be set to true. This flag will also be set if a new sample stream is created.
    Note that previously passed TrackSelections are no longer valid, and any references to them must be updated to point to the new selections.
    This method is only called after the period has been prepared.
    
    Specified by:
    
    selectTracks in interface MediaPeriod
    
    Parameters:
    
    selections - The renderer track selections.
    
    mayRetainStreamFlags - Flags indicating whether the existing sample stream can be retained for each track selection. A true value indicates that the selection is equivalent to the one that was previously passed, and that the caller does not require that the sample stream be recreated. If a retained sample stream holds any references to the track selection then they must be updated to point to the new selection.
    
    streams - The existing sample streams, which will be updated to reflect the provided selections.
    
    streamResetFlags - Will be updated to indicate new sample streams, and sample streams that have been retained but with the requirement that the consuming renderer be reset.
    
    positionUs - The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position.
    
    Returns:
    
    The actual position at which the tracks were enabled, in microseconds.
  - discardBuffer
```
public void discardBuffer(long positionUs,
                          boolean toKeyframe)
```
    Description copied from interface: MediaPeriod
    
    Discards buffered media up to the specified position.
    This method is only called after the period has been prepared.
    
    Specified by:
    
    discardBuffer in interface MediaPeriod
    
    Parameters:
    
    positionUs - The position in microseconds.
    
    toKeyframe - If true then for each track discards samples up to the keyframe before or at the specified position, rather than any sample before or at that position.
  - readDiscontinuity
```
public long readDiscontinuity()
```
    Description copied from interface: MediaPeriod
    
    Attempts to read a discontinuity.
    After this method has returned a value other than C.TIME_UNSET, all SampleStreams provided by the period are guaranteed to start from a key frame.
    This method is only called after the period has been prepared and before reading from any SampleStreams provided by the period.
    
    Specified by:
    
    readDiscontinuity in interface MediaPeriod
    
    Returns:
    
    If a discontinuity was read then the playback position in microseconds after the discontinuity. Else C.TIME_UNSET.
  - getBufferedPositionUs
```
public long getBufferedPositionUs()
```
    Description copied from interface: MediaPeriod
    
    Returns an estimate of the position up to which data is buffered for the enabled tracks.
    This method is only called when at least one track is selected.
    
    Specified by:
    
    getBufferedPositionUs in interface MediaPeriod
    
    Specified by:
    
    getBufferedPositionUs in interface SequenceableLoader
    
    Returns:
    
    An estimate of the absolute position in microseconds up to which data is buffered, or C.TIME_END_OF_SOURCE if the track is fully buffered.
  - seekToUs
```
public long seekToUs(long positionUs)
```
    Description copied from interface: MediaPeriod
    
    Attempts to seek to the specified position in microseconds.
    After this method has been called, all SampleStreams provided by the period are guaranteed to start from a key frame.
    This method is only called when at least one track is selected.
    
    Specified by:
    
    seekToUs in interface MediaPeriod
    
    Parameters:
    
    positionUs - The seek position in microseconds.
    
    Returns:
    
    The actual position to which the period was seeked, in microseconds.
  - getAdjustedSeekPositionUs
```
public long getAdjustedSeekPositionUs(long positionUs,
                                      SeekParameters seekParameters)
```
    Description copied from interface: MediaPeriod
    
    Returns the position to which a seek will be performed, given the specified seek position and SeekParameters.
    This method is only called after the period has been prepared.
    
    Specified by:
    
    getAdjustedSeekPositionUs in interface MediaPeriod
    
    Parameters:
    
    positionUs - The seek position in microseconds.
    
    seekParameters - Parameters that control how the seek is performed. Implementations may apply seek parameters on a best effort basis.
    
    Returns:
    
    The actual position to which a seek will be performed, in microseconds.
  - getNextLoadPositionUs
```
public long getNextLoadPositionUs()
```
    Description copied from interface: MediaPeriod
    
    Returns the next load time, or C.TIME_END_OF_SOURCE if loading has finished.
    This method is only called after the period has been prepared. It may be called when no tracks are selected.
    
    Specified by:
    
    getNextLoadPositionUs in interface MediaPeriod
    
    Specified by:
    
    getNextLoadPositionUs in interface SequenceableLoader
  - reevaluateBuffer
```
public void reevaluateBuffer(long positionUs)
```
    Description copied from interface: MediaPeriod
    
    Re-evaluates the buffer given the playback position.
    This method is only called after the period has been prepared.
    A period may choose to discard buffered media or cancel ongoing loads so that media can be re-buffered in a different quality.
    
    Specified by:
    
    reevaluateBuffer in interface MediaPeriod
    
    Specified by:
    
    reevaluateBuffer in interface SequenceableLoader
    
    Parameters:
    
    positionUs - The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position in this period minus the duration of any media in previous periods still to be played.
  - continueLoading
```
public boolean continueLoading(long positionUs)
```
    Description copied from interface: MediaPeriod
    
    Attempts to continue loading.
    This method may be called both during and after the period has been prepared.
    A period may call SequenceableLoader.Callback.onContinueLoadingRequested(SequenceableLoader) on the MediaPeriod.Callback passed to MediaPeriod.prepare(Callback, long) to request that this method be called when the period is permitted to continue loading data. A period may do this both during and after preparation.
    
    Specified by:
    
    continueLoading in interface MediaPeriod
    
    Specified by:
    
    continueLoading in interface SequenceableLoader
    
    Parameters:
    
    positionUs - The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position in this period minus the duration of any media in previous periods still to be played.
    
    Returns:
    
    True if progress was made, meaning that MediaPeriod.getNextLoadPositionUs() will return a different value than prior to the call. False otherwise.
  - isLoading
```
public boolean isLoading()
```
    Description copied from interface: MediaPeriod
    
    Returns whether the media period is currently loading.
    
    Specified by:
    
    isLoading in interface MediaPeriod
    
    Specified by:
    
    isLoading in interface SequenceableLoader
  - onContinueLoadingRequested
```
public void onContinueLoadingRequested(MediaPeriod source)
```
    Description copied from interface: SequenceableLoader.Callback
    
    Called by the loader to indicate that it wishes for its SequenceableLoader.continueLoading(long) method to be called when it can continue to load data. Called on the playback thread.
    
    Specified by:
    
    onContinueLoadingRequested in interface SequenceableLoader.Callback<MediaPeriod>
  - onPrepared
```
public void onPrepared(MediaPeriod mediaPeriod)
```
    Description copied from interface: MediaPeriod.Callback
    
    Called when preparation completes.
    Called on the playback thread. After invoking this method, the MediaPeriod can expect for MediaPeriod.selectTracks(ExoTrackSelection[], boolean[], SampleStream[], boolean[], long) to be called with the initial track selection.
    
    Specified by:
    
    onPrepared in interface MediaPeriod.Callback
    
    Parameters:
    
    mediaPeriod - The prepared MediaPeriod.

Class MaskingMediaPeriod

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.android.exoplayer2.source.MediaPeriod

Field Summary

Constructor Summary

Method Summary

Methods inherited from interface com.google.android.exoplayer2.source.MediaPeriod

Methods inherited from class java.lang.Object

Field Detail

id

Constructor Detail

MaskingMediaPeriod

Method Detail

setPrepareListener

getPreparePositionUs

overridePreparePositionUs

getPreparePositionOverrideUs

setMediaSource

createPeriod

releasePeriod

prepare

maybeThrowPrepareError

getTrackGroups

selectTracks

discardBuffer

readDiscontinuity

getBufferedPositionUs

seekToUs

getAdjustedSeekPositionUs

getNextLoadPositionUs

reevaluateBuffer

continueLoading

isLoading

onContinueLoadingRequested

onPrepared