RandomTrackSelection

@UnstableApi
public final class RandomTrackSelection extends BaseTrackSelection

java.lang.Object
   ↳ androidx.media3.exoplayer.trackselection.BaseTrackSelection
     ↳ androidx.media3.exoplayer.trackselection.RandomTrackSelection

An ExoTrackSelection whose selected track is updated randomly.

Summary

Nested types

Factory for RandomTrackSelection instances.

Public fields
int

Public constructors
RandomTrackSelection(
    TrackGroup group,
    int[] tracks,
    @TrackSelection.Type int type,
    Random random
)

Creates a new instance.

Public methods
int

Returns the index of the selected track.
@Nullable Object

Returns optional data associated with the current track selection.
int

Returns the reason for the current track selection.
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.

Inherited Constants
From androidx.media3.exoplayer.trackselection.TrackSelection
static final int

The first value that can be used for application specific track selection types.
static final int

An unspecified track selection type.

Inherited fields
From androidx.media3.exoplayer.trackselection.BaseTrackSelection
final TrackGroup

The selected TrackGroup.
final int

The number of selected tracks within the TrackGroup.
boolean

The current value of whether playback will proceed when ready.
final int[]

The indices of the selected tracks in group, in order of decreasing bandwidth.
final int

The type of the selection.

Inherited methods
From androidx.media3.exoplayer.trackselection.BaseTrackSelection
void

Disables this track selection.
void

Enables the track selection.
boolean
int
evaluateQueueSize(long playbackPositionUs, List<MediaChunk> queue)

Returns the number of chunks that should be retained in the queue.
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.
final Format
getFormat(int index)

Returns the format of the track at a given index in the selection.
final int

Returns the index in the track group of the track at a given index in the selection.
final boolean

Returns whether the playback using this track selection will proceed when ready.
final Format

Returns the Format of the individual selected track.
final int

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

Returns the TrackGroup to which the selected tracks belong.
final int

Returns an integer specifying the type of the selection, or TYPE_UNSET if not specified.
int
final int
indexOf(Format format)

Returns the index in the selection of the track with the specified format.
final int
indexOf(int indexInTrackGroup)

Returns the index in the selection of the track with the specified index in the track group.
boolean
isTrackExcluded(int index, long nowMs)

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

Returns the number of tracks in the selection.
void
@CallSuper
onPlayWhenReadyChanged(boolean playWhenReady)

Called to notify when the playback is paused or resumed.
void
onPlaybackSpeed(float playbackSpeed)

Called to notify the selection of the current playback speed.
From androidx.media3.exoplayer.trackselection.ExoTrackSelection
long

Returns the most recent bitrate estimate utilised for track selection.
void

Called to notify the selection of a position discontinuity.
void

Called to notify when a rebuffer occurred.
boolean
shouldCancelChunkLoad(
    long playbackPositionUs,
    Chunk loadingChunk,
    List<MediaChunk> queue
)

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

Public fields

selectedIndex

public int selectedIndex

Public constructors

RandomTrackSelection

public RandomTrackSelection(
    TrackGroup group,
    int[] tracks,
    @TrackSelection.Type int type,
    Random random
)

Creates a new instance.

Parameters
TrackGroup group

The TrackGroup. Must not be null.
int[] tracks

The indices of the selected tracks within the TrackGroup. Must not be null or empty. May be in any order.
@TrackSelection.Type int type

The Type of this track selection.
Random random

A source of random numbers.

Public methods

getSelectedIndex

public int getSelectedIndex()

Returns the index of the selected track.

getSelectionData

public @Nullable Object getSelectionData()

Returns optional data associated with the current track selection.

getSelectionReason

public int getSelectionReason()

Returns the reason for the current track selection.

updateSelectedTrack

public 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.

Parameters
long playbackPositionUs

The current playback position in microseconds. If playback of the period to which this track selection belongs has not yet started, the value will be the starting position in the period minus the duration of any media in previous periods still to be played.
long bufferedDurationUs

The duration of media currently buffered from the current playback position, in microseconds. Note that the next load position can be calculated as (playbackPositionUs + bufferedDurationUs).
long availableDurationUs

The duration of media available for buffering from the current playback position, in microseconds, or TIME_UNSET if media can be buffered to the end of the current period. Note that if not set to TIME_UNSET, the position up to which media is available for buffering can be calculated as (playbackPositionUs + availableDurationUs).
List<MediaChunk> queue

The queue of already buffered MediaChunks. Must not be modified.
MediaChunkIterator[] mediaChunkIterators

An array of MediaChunkIterators providing information about the sequence of upcoming media chunks for each track in the selection. All iterators start from the media chunk which will be loaded next if the respective track is selected. Note that this information may not be available for all tracks, and so some iterators may be empty.