ExoTrackSelection

abstract void disable()

Disables this track selection. No further dynamic changes via updateSelectedTrack, evaluateQueueSize or shouldCancelChunkLoad will happen after this call.

This method may only be called when the track selection is already enabled.

abstract void enable()

Enables the track selection. Dynamic changes via updateSelectedTrack, evaluateQueueSize or shouldCancelChunkLoad will only happen after this call.

This method may not be called when the track selection is already enabled.

abstract int evaluateQueueSize(long playbackPositionUs, List<MediaChunk> queue)

Returns the number of chunks that should be retained in the queue.

May be called by sources that load media in discrete MediaChunks and support discarding of buffered chunks.

To avoid excessive re-buffering, implementations should normally return the size of the queue. An example of a case where a smaller value may be returned is if network conditions have improved dramatically, allowing chunks to be discarded and re-buffered in a track of significantly higher quality. Discarding chunks may allow faster switching to a higher quality track in this case.

Note that even if the source supports discarding of buffered chunks, the actual number of discarded chunks is not guaranteed. The source will call updateSelectedTrack with the updated queue of chunks before loading a new chunk to allow switching to another quality.

This method will only be called when the selection is enabled and none of the MediaChunks in the queue are currently loading.

abstract boolean excludeTrack(int index, long exclusionDurationMs)

Attempts to exclude the track at the specified index in the selection, making it ineligible for selection by calls to updateSelectedTrack for the specified period of time.

Exclusion will fail if all other tracks are currently excluded. If excluding the currently selected track, note that it will remain selected until the next call to updateSelectedTrack.

This method will only be called when the selection is enabled.

default long getLatestBitrateEstimate()

Returns the most recent bitrate estimate utilised for track selection.

The default behavior is to return RATE_UNSET_INT, indicating that the bitrate estimate was not computed for the track selection decision.

abstract Format getSelectedFormat()

Returns the Format of the individual selected track.

abstract int getSelectedIndex()

Returns the index of the selected track.

abstract int getSelectedIndexInTrackGroup()

Returns the index in the track group of the individual selected track.

abstract @Nullable Object getSelectionData()

Returns optional data associated with the current track selection.

@C.SelectionReason
abstract int getSelectionReason()

Returns the reason for the current track selection.

abstract boolean isTrackExcluded(int index, long nowMs)

Returns whether the track at the specified index in the selection is excluded.

default void onDiscontinuity()

Called to notify the selection of a position discontinuity.

This happens when the playback position jumps, e.g., as a result of a seek being performed.

default void onPlayWhenReadyChanged(boolean playWhenReady)

Called to notify when the playback is paused or resumed.

abstract void onPlaybackSpeed(float playbackSpeed)

Called to notify the selection of the current playback speed. The playback speed may affect adaptive track selection.

default void onRebuffer()

Called to notify when a rebuffer occurred.

A rebuffer is defined to be caused by buffer depletion rather than a user action. Hence this method is not called during initial buffering or when buffering as a result of a seek operation.

default boolean shouldCancelChunkLoad(
    long playbackPositionUs,
    Chunk loadingChunk,
    List<MediaChunk> queue
)

Returns whether an ongoing load of a chunk should be canceled.

May be called by sources that load media in discrete MediaChunks and support canceling the ongoing chunk load. The ongoing chunk load is either the last in the queue or another type of Chunk, for example, if the source loads initialization or encryption data.

To avoid excessive re-buffering, implementations should normally return false. An example where true might be returned is if a load of a high quality chunk gets stuck and canceling this load in favor of a lower quality alternative may avoid a rebuffer.

The source will call evaluateQueueSize after the cancelation finishes to allow discarding of chunks, and updateSelectedTrack before loading a new chunk to allow switching to another quality.

This method will only be called when the selection is enabled.

abstract void updateSelectedTrack(
    long playbackPositionUs,
    long bufferedDurationUs,
    long availableDurationUs,
    List<MediaChunk> queue,
    MediaChunkIterator[] mediaChunkIterators
)

Updates the selected track for sources that load media in discrete MediaChunks.

This method will only be called when the selection is enabled.