com.google.android.exoplayer2.source

Class ClippingMediaPeriod

java.lang.Object

com.google.android.exoplayer2.source.ClippingMediaPeriod

All Implemented Interfaces:

MediaPeriod, MediaPeriod.Callback, SequenceableLoader, SequenceableLoader.Callback<MediaPeriod>

public final class ClippingMediaPeriod
extends java.lang.Object
implements MediaPeriod, MediaPeriod.Callback

Wraps a MediaPeriod and clips its SampleStreams to provide a subsequence of their samples.

Nested Class Summary

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

MediaPeriod.Callback

Field Summary

Fields

Modifier and Type	Field and Description
MediaPeriod	mediaPeriod The MediaPeriod wrapped by this clipping media period.

Constructor Summary

Constructors

Constructor and Description
ClippingMediaPeriod(MediaPeriod mediaPeriod, boolean enableInitialDiscontinuity) Creates a new clipping media period that provides a clipped view of the specified MediaPeriod's sample streams.

Method Summary

Modifier and Type	Method and Description
boolean	continueLoading(long positionUs) Attempts to continue loading.
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.
TrackGroupArray	getTrackGroups() Returns the TrackGroups exposed by the period.
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	prepare(MediaPeriod.Callback callback, long positionUs) Prepares this media period asynchronously.
long	readDiscontinuity() Attempts to read a discontinuity.
void	reevaluateBuffer(long positionUs) Re-evaluates the buffer given the playback position.
long	seekToUs(long positionUs) Attempts to seek to the specified position in microseconds.
long	selectTracks(TrackSelection[] selections, boolean[] mayRetainStreamFlags, SampleStream[] streams, boolean[] streamResetFlags, long positionUs) Performs a track selection.
void	setClipping(long startUs, long endUs) Sets the clipping start/end times for this period, in microseconds.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

mediaPeriod

public final MediaPeriod mediaPeriod

The MediaPeriod wrapped by this clipping media period.

Constructor Detail

ClippingMediaPeriod

public ClippingMediaPeriod(MediaPeriod mediaPeriod,
                           boolean enableInitialDiscontinuity)

Creates a new clipping media period that provides a clipped view of the specified MediaPeriod's sample streams.

The clipping start/end positions must be specified by calling setClipping(long, long) on the playback thread before preparation completes.

If the start point is guaranteed to be a key frame, pass false to enableInitialPositionDiscontinuity to suppress an initial discontinuity when the period is first read from.

Parameters:

mediaPeriod - The media period to clip.

enableInitialDiscontinuity - Whether the initial discontinuity should be enabled.

Method Detail

setClipping

public void setClipping(long startUs,
                        long endUs)

Sets the clipping start/end times for this period, in microseconds.

Parameters:

startUs - The clipping start time, in microseconds.

endUs - The clipping end time, in microseconds, or C.TIME_END_OF_SOURCE to indicate the end of the period.

prepare

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

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.Listener.onSourceInfoRefreshed(MediaSource, Timeline, Object) 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.

positionUs - The expected starting position, in microseconds.

maybeThrowPrepareError

public void maybeThrowPrepareError()
                            throws java.io.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 should only be called before the period has completed preparation.

Specified by:

maybeThrowPrepareError in interface MediaPeriod

Throws:

java.io.IOException - The underlying error.

getTrackGroups

public TrackGroupArray getTrackGroups()

Description copied from interface: MediaPeriod

Returns the TrackGroups exposed by the period.

This method should only be called after the period has been prepared.

Specified by:

getTrackGroups in interface MediaPeriod

Returns:

The TrackGroups.

selectTracks

public long selectTracks(TrackSelection[] selections,
                         boolean[] mayRetainStreamFlags,
                         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.

This method should only be 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 selection. A true value indicates that the selection is unchanged, and that the caller does not require that the sample stream be recreated.

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 should only be 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.

reevaluateBuffer

public void reevaluateBuffer(long positionUs)

Description copied from interface: MediaPeriod

Re-evaluates the buffer given the playback position.

This method should only be called after the period has been prepared.

A period may choose to discard buffered media so that it 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.

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 should only be called after the period has been prepared.

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 should only be 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 should only be 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 should only be 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 should only be 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

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.

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(TrackSelection[], boolean[], SampleStream[], boolean[], long) to be called with the initial track selection.

Specified by:

onPrepared in interface MediaPeriod.Callback

Parameters:

mediaPeriod - The prepared MediaPeriod.

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>