MaskingMediaPeriod


@UnstableApi
public final class MaskingMediaPeriod implements MediaPeriod, MediaPeriod.Callback


Media period that defers calling createPeriod on a given source until createPeriod 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.

Summary

Nested types

Listener for preparation events.

Public fields

final MediaSource.MediaPeriodId

The MediaPeriodId used to create the masking media period.

long
final long

Public constructors

MaskingMediaPeriod(
    MediaSource.MediaPeriodId id,
    Allocator allocator,
    long preparePositionUs
)

Creates a new masking media period.

Public methods

boolean

Attempts to continue loading.

void

Calls createPeriod on the wrapped source then prepares it if prepare 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

Returns an estimate of the position up to which data is buffered for the enabled tracks.

long

Returns the next load time, or TIME_END_OF_SOURCE if loading has finished.

long

Returns the prepare position override set by overridePreparePositionUs.

long

Returns the position at which the masking media period was prepared, in microseconds.

TrackGroupArray

Returns the TrackGroups exposed by the period.

boolean

Returns whether the media period is currently loading.

void

Throws an error that's preventing the period from becoming prepared.

void

Called by the loader to indicate that it wishes for its continueLoading 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 positionUs)

Prepares this media period asynchronously.

long

Attempts to read a discontinuity.

void
reevaluateBuffer(long positionUs)

Re-evaluates the buffer given the playback position.

void

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

Sets the MediaSource that will create the underlying media period.

void

Sets a listener for preparation events.

Inherited methods

From androidx.media3.exoplayer.source.MediaPeriod
List<StreamKey>

Returns a list of StreamKeys which allow to filter the media in this period to load only the parts needed to play the provided TrackSelections.

Public fields

id

public final MediaSource.MediaPeriodId id

The MediaPeriodId used to create the masking media period.

preparePositionOverrideUs

public long preparePositionOverrideUs

preparePositionUs

public final long preparePositionUs

Public constructors

MaskingMediaPeriod

public MaskingMediaPeriod(
    MediaSource.MediaPeriodId id,
    Allocator allocator,
    long preparePositionUs
)

Creates a new masking media period. The media source must be set via setMediaSource before preparation can start.

Parameters
MediaSource.MediaPeriodId id

The identifier used to create the masking media period.

Allocator allocator

The allocator used to create the media period.

long preparePositionUs

The expected start position, in microseconds.

Public methods

continueLoading

public boolean continueLoading(LoadingInfo loadingInfo)

Attempts to continue loading.

This method may be called both during and after the period has been prepared.

A period may call onContinueLoadingRequested on the Callback passed to prepare 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.

Parameters
LoadingInfo loadingInfo

The LoadingInfo when attempting to continue loading.

Returns
boolean

True if progress was made, meaning that getNextLoadPositionUs will return a different value than prior to the call. False otherwise.

createPeriod

public void createPeriod(MediaSource.MediaPeriodId id)

Calls createPeriod on the wrapped source then prepares it if prepare has been called. Call releasePeriod to release the period.

Parameters
MediaSource.MediaPeriodId id

The identifier that should be used to create the media period from the media source.

discardBuffer

public void discardBuffer(long positionUs, boolean toKeyframe)

Discards buffered media up to the specified position.

This method is only called after the period has been prepared.

Parameters
long positionUs

The position in microseconds.

boolean 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.

getAdjustedSeekPositionUs

public long getAdjustedSeekPositionUs(
    long positionUs,
    SeekParameters seekParameters
)

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.

Parameters
long positionUs

The seek position in microseconds.

SeekParameters seekParameters

Parameters that control how the seek is performed. Implementations may apply seek parameters on a best effort basis.

Returns
long

The actual position to which a seek will be performed, in microseconds.

getBufferedPositionUs

public long getBufferedPositionUs()

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.

Returns
long

An estimate of the absolute position in microseconds up to which data is buffered, or TIME_END_OF_SOURCE if the track is fully buffered.

getNextLoadPositionUs

public long getNextLoadPositionUs()

Returns the next load time, or 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.

getPreparePositionOverrideUs

public long getPreparePositionOverrideUs()

Returns the prepare position override set by overridePreparePositionUs.

getPreparePositionUs

public long getPreparePositionUs()

Returns the position at which the masking media period was prepared, in microseconds.

getTrackGroups

public TrackGroupArray getTrackGroups()

Returns the TrackGroups exposed by the period.

This method is only called after the period has been prepared.

Returns
TrackGroupArray

The TrackGroups.

isLoading

public boolean isLoading()

Returns whether the media period is currently loading.

maybeThrowPrepareError

public void maybeThrowPrepareError()

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.

Throws
java.io.IOException

The underlying error.

onContinueLoadingRequested

public void onContinueLoadingRequested(MediaPeriod source)

Called by the loader to indicate that it wishes for its continueLoading method to be called when it can continue to load data. Called on the playback thread.

onPrepared

public void onPrepared(MediaPeriod mediaPeriod)

Called when preparation completes.

Called on the playback thread. After invoking this method, the MediaPeriod can expect for selectTracks to be called with the initial track selection.

Parameters
MediaPeriod mediaPeriod

The prepared MediaPeriod.

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.

Parameters
long preparePositionUs

The default prepare position to use, in microseconds.

prepare

public void prepare(MediaPeriod.Callback callback, long positionUs)

Prepares this media period asynchronously.

callback.onPrepared is called when preparation completes. If preparation fails, maybeThrowPrepareError will throw an IOException.

If preparation succeeds and results in a source timeline change (e.g. the period duration becoming known), onSourceInfoRefreshed will be called before callback.onPrepared.

Parameters
MediaPeriod.Callback callback

Callback to receive updates from this period, including being notified when preparation completes.

long positionUs

The expected starting position, in microseconds.

readDiscontinuity

public long readDiscontinuity()

Attempts to read a discontinuity.

A discontinuity implies that the provided SampleStreams will start from a new playback position and any output pipelines need to be reset. This happens for example if the streams provide decode-only samples before the intended playback start position that need to be dropped.

After this method has returned a value other than 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.

Returns
long

The playback position after the discontinuity, in microseconds, or TIME_UNSET if there is no discontinuity.

reevaluateBuffer

public void reevaluateBuffer(long positionUs)

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.

Parameters
long 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.

releasePeriod

public void releasePeriod()

Releases the period.

seekToUs

public long seekToUs(long positionUs)

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.

Parameters
long positionUs

The seek position in microseconds.

Returns
long

The actual position to which the period was seeked, in microseconds.

selectTracks

public long selectTracks(
    @NullableType ExoTrackSelection[] selections,
    boolean[] mayRetainStreamFlags,
    @NullableType SampleStream[] streams,
    boolean[] streamResetFlags,
    long positionUs
)

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.

Parameters
@NullableType ExoTrackSelection[] selections

The renderer track selections.

boolean[] 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.

@NullableType SampleStream[] streams

The existing sample streams, which will be updated to reflect the provided selections.

boolean[] 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.

long positionUs

The current playback position in microseconds. If playback of this period has not yet started, the value will be the starting position.

Returns
long

The actual position at which the tracks were enabled, in microseconds.

setMediaSource

public void setMediaSource(MediaSource mediaSource)

Sets the MediaSource that will create the underlying media period.

setPrepareListener

public void setPrepareListener(MaskingMediaPeriod.PrepareListener listener)

Sets a listener for preparation events.

Parameters
MaskingMediaPeriod.PrepareListener 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.