TrackSelector (ExoPlayer library) - Exoplayer

Package com.google.android.exoplayer2.trackselection

Class TrackSelector

java.lang.Object
- com.google.android.exoplayer2.trackselection.TrackSelector
Direct Known Subclasses:MappingTrackSelector

[@Deprecated](https://developer.android.com/reference/java/lang/Deprecated.html "class or interface in java.lang")public abstract classTrackSelectorextends[Object](https://developer.android.com/reference/java/lang/Object.html "class or interface in java.lang")

Deprecated. com.google.android.exoplayer2 is deprecated. Please migrate to androidx.media3 (which contains the same ExoPlayer code). See the migration guide for more details, including a script to help with the migration.

The component of an ExoPlayer responsible for selecting tracks to be consumed by each of the player's Renderers. The DefaultTrackSelector implementation should be suitable for most use cases.

Interactions with the player

The following interactions occur between the player and its track selector during playback.

When the player is created it will initialize the track selector by calling init(InvalidationListener, BandwidthMeter).
When the player needs to make a track selection it will call selectTracks(RendererCapabilities[], TrackGroupArray, MediaPeriodId, Timeline). This typically occurs at the start of playback, when the player starts to buffer a new period of the media being played, and when the track selector invalidates its previous selections.
The player may perform a track selection well in advance of the selected tracks becoming active, where active is defined to mean that the renderers are actually consuming media corresponding to the selection that was made. For example when playing media containing multiple periods, the track selection for a period is made when the player starts to buffer that period. Hence if the player's buffering policy is to maintain a 30 second buffer, the selection will occur approximately 30 seconds in advance of it becoming active. In fact the selection may never become active, for example if the user seeks to some other period of the media during the 30 second gap. The player indicates to the track selector when a selection it has previously made becomes active by calling onSelectionActivated(Object).
If the track selector wishes to indicate to the player that selections it has previously made are invalid, it can do so by calling TrackSelector.InvalidationListener.onTrackSelectionsInvalidated() on the TrackSelector.InvalidationListener that was passed to init(InvalidationListener, BandwidthMeter). A track selector may wish to do this if its configuration has changed, for example if it now wishes to prefer audio tracks in a particular language. This will trigger the player to make new track selections. Note that the player will have to re-buffer in the case that the new track selection for the currently playing period differs from the one that was invalidated. Implementing subclasses can trigger invalidation by calling invalidate(), which will call TrackSelector.InvalidationListener.onTrackSelectionsInvalidated().
When the player is released, it will release the track selector by calling release().

Renderer configuration

The TrackSelectorResult returned by selectTracks(RendererCapabilities[], TrackGroupArray, MediaPeriodId, Timeline) contains not only TrackSelections for each renderer, but also RendererConfigurations defining configuration parameters that the renderers should apply when consuming the corresponding media. Whilst it may seem counter- intuitive for a track selector to also specify renderer configuration information, in practice the two are tightly bound together. It may only be possible to play a certain combination tracks if the renderers are configured in a particular way. Equally, it may only be possible to configure renderers in a particular way if certain tracks are selected. Hence it makes sense to determine the track selection and corresponding renderer configurations in a single step.

Threading model

All calls made by the player into the track selector are on the player's internal playback thread. The track selector may call TrackSelector.InvalidationListener.onTrackSelectionsInvalidated() from any thread.

Nested Class Summary

Nested Classes | Modifier and Type | Class | Description | | --- | --- | --- | | static interface | TrackSelector.InvalidationListener | Deprecated.

Notified when selections previously made by a TrackSelector are no longer valid. |

Constructor Summary

Constructors | Constructor | Description | | --- | --- | | TrackSelector() | Deprecated. |

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods | Modifier and Type | Method | Description | | --- | --- | --- | | protected BandwidthMeter | getBandwidthMeter() | Deprecated.

Returns a bandwidth meter which can be used by track selections to select tracks. | | TrackSelectionParameters | getParameters() | Deprecated.

Returns the current parameters for track selection. | | RendererCapabilities.Listener | getRendererCapabilitiesListener() | Deprecated.

Returns the RendererCapabilities.Listener that the concrete instance uses to listen to the renderer capabilities changes. | | void | init(TrackSelector.InvalidationListener listener, BandwidthMeter bandwidthMeter) | Deprecated.

Called by the player to initialize the selector. | | protected void | invalidate() | Deprecated.

Calls TrackSelector.InvalidationListener.onTrackSelectionsInvalidated() to invalidate all previously generated track selections. | | protected void | invalidateForRendererCapabilitiesChange(Renderer renderer) | Deprecated.

Calls TrackSelector.InvalidationListener.onRendererCapabilitiesChanged(Renderer) to invalidate all previously generated track selections because a renderer's capabilities have changed. | | boolean | isSetParametersSupported() | Deprecated.

Returns if this TrackSelector supports setParameters(TrackSelectionParameters). | | abstract void | onSelectionActivated(Object info) | Deprecated.

Called by the player when a TrackSelectorResult previously generated by selectTracks(RendererCapabilities[], TrackGroupArray, MediaPeriodId, Timeline) is activated. | | void | release() | Deprecated.

Called by the player to release the selector. | | abstract TrackSelectorResult | selectTracks(RendererCapabilities[] rendererCapabilities, TrackGroupArray trackGroups, MediaSource.MediaPeriodId periodId, Timeline timeline) | Deprecated.

Called by the player to perform a track selection. | | void | setAudioAttributes(AudioAttributes audioAttributes) | Deprecated.

Called by the player to set the AudioAttributes that will be used for playback. | | void | setParameters(TrackSelectionParameters parameters) | Deprecated.

Called by the player to provide parameters for track selection. |

Methods inherited from class java.lang.Object

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

Constructor Detail

TrackSelector

public TrackSelector()

Deprecated.

Method Detail

init

@CallSuper
public void init([TrackSelector.InvalidationListener](TrackSelector.InvalidationListener.html "interface in com.google.android.exoplayer2.trackselection")listener,[BandwidthMeter](../upstream/BandwidthMeter.html "interface in com.google.android.exoplayer2.upstream")bandwidthMeter)

Deprecated.

Called by the player to initialize the selector. Parameters:listener - An invalidation listener that the selector can call to indicate that selections it has previously made are no longer valid.bandwidthMeter - A bandwidth meter which can be used by track selections to select tracks.

release

@CallSuper
public void release()

Deprecated.

Called by the player to release the selector. The selector cannot be used until init(InvalidationListener, BandwidthMeter) is called again.

selectTracks

public abstract[TrackSelectorResult](TrackSelectorResult.html "class in com.google.android.exoplayer2.trackselection")selectTracks([RendererCapabilities](../RendererCapabilities.html "interface in com.google.android.exoplayer2")[] rendererCapabilities,[TrackGroupArray](../source/TrackGroupArray.html "class in com.google.android.exoplayer2.source")trackGroups,[MediaSource.MediaPeriodId](../source/MediaSource.MediaPeriodId.html "class in com.google.android.exoplayer2.source")periodId,[Timeline](../Timeline.html "class in com.google.android.exoplayer2")timeline)
                                          throws[ExoPlaybackException](../ExoPlaybackException.html "class in com.google.android.exoplayer2")

Deprecated.

Called by the player to perform a track selection. Parameters:rendererCapabilities - The RendererCapabilities of the renderers for which tracks are to be selected.trackGroups - The available track groups.periodId - The MediaSource.MediaPeriodId of the period for which tracks are to be selected.timeline - The Timeline holding the period for which tracks are to be selected.Returns:A TrackSelectorResult describing the track selections.Throws:ExoPlaybackException - If an error occurs selecting tracks.

onSelectionActivated

public abstract void onSelectionActivated(@Nullable[Object](https://developer.android.com/reference/java/lang/Object.html "class or interface in java.lang")info)

Deprecated.

getParameters

public[TrackSelectionParameters](TrackSelectionParameters.html "class in com.google.android.exoplayer2.trackselection")getParameters()

Deprecated.

Returns the current parameters for track selection.

setParameters

public void setParameters([TrackSelectionParameters](TrackSelectionParameters.html "class in com.google.android.exoplayer2.trackselection")parameters)

Deprecated.

Called by the player to provide parameters for track selection.

Only supported if isSetParametersSupported() returns true.

Parameters:parameters - The parameters for track selection.

isSetParametersSupported

public boolean isSetParametersSupported()

Deprecated.

Returns if this TrackSelector supports setParameters(TrackSelectionParameters).

The same value is always returned for a given TrackSelector instance.

setAudioAttributes

public void setAudioAttributes([AudioAttributes](../audio/AudioAttributes.html "class in com.google.android.exoplayer2.audio")audioAttributes)

Deprecated.

Called by the player to set the AudioAttributes that will be used for playback.

getRendererCapabilitiesListener

@Nullable
public[RendererCapabilities.Listener](../RendererCapabilities.Listener.html "interface in com.google.android.exoplayer2")getRendererCapabilitiesListener()

Deprecated.

Returns the RendererCapabilities.Listener that the concrete instance uses to listen to the renderer capabilities changes. May be null if the implementation does not listen to the renderer capabilities changes.

invalidate

protected final void invalidate()

Deprecated.

Calls TrackSelector.InvalidationListener.onTrackSelectionsInvalidated() to invalidate all previously generated track selections.

invalidateForRendererCapabilitiesChange

protected final void invalidateForRendererCapabilitiesChange([Renderer](../Renderer.html "interface in com.google.android.exoplayer2")renderer)

Deprecated.

Calls TrackSelector.InvalidationListener.onRendererCapabilitiesChanged(Renderer) to invalidate all previously generated track selections because a renderer's capabilities have changed. Parameters:renderer - The renderer whose capabilities changed.

getBandwidthMeter

protected final[BandwidthMeter](../upstream/BandwidthMeter.html "interface in com.google.android.exoplayer2.upstream")getBandwidthMeter()

Deprecated.

Returns a bandwidth meter which can be used by track selections to select tracks. Must only be called when the track selector is initialized.