TrackSelectionUtil.java
/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.media3.exoplayer.trackselection;
import android.os.SystemClock;
import androidx.annotation.Nullable;
import androidx.media3.common.TrackGroupArray;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.exoplayer.trackselection.DefaultTrackSelector.SelectionOverride;
import androidx.media3.exoplayer.trackselection.ExoTrackSelection.Definition;
import androidx.media3.exoplayer.upstream.LoadErrorHandlingPolicy;
import org.checkerframework.checker.nullness.compatqual.NullableType;
/** Track selection related utility methods. */
@UnstableApi
public final class TrackSelectionUtil {
private TrackSelectionUtil() {}
/** Functional interface to create a single adaptive track selection. */
public interface AdaptiveTrackSelectionFactory {
/**
* Creates an adaptive track selection for the provided track selection definition.
*
* @param trackSelectionDefinition A {@link Definition} for the track selection.
* @return The created track selection.
*/
ExoTrackSelection createAdaptiveTrackSelection(Definition trackSelectionDefinition);
}
/**
* Creates track selections for an array of track selection definitions, with at most one
* multi-track adaptive selection.
*
* @param definitions The list of track selection {@link Definition definitions}. May include null
* values.
* @param adaptiveTrackSelectionFactory A factory for the multi-track adaptive track selection.
* @return The array of created track selection. For null entries in {@code definitions} returns
* null values.
*/
public static @NullableType ExoTrackSelection[] createTrackSelectionsForDefinitions(
@NullableType Definition[] definitions,
AdaptiveTrackSelectionFactory adaptiveTrackSelectionFactory) {
ExoTrackSelection[] selections = new ExoTrackSelection[definitions.length];
boolean createdAdaptiveTrackSelection = false;
for (int i = 0; i < definitions.length; i++) {
Definition definition = definitions[i];
if (definition == null) {
continue;
}
if (definition.tracks.length > 1 && !createdAdaptiveTrackSelection) {
createdAdaptiveTrackSelection = true;
selections[i] = adaptiveTrackSelectionFactory.createAdaptiveTrackSelection(definition);
} else {
selections[i] =
new FixedTrackSelection(
definition.group, definition.tracks[0], /* type= */ definition.type);
}
}
return selections;
}
/**
* Updates {@link DefaultTrackSelector.Parameters} with an override.
*
* @param parameters The current {@link DefaultTrackSelector.Parameters} to build upon.
* @param rendererIndex The renderer index to update.
* @param trackGroupArray The {@link TrackGroupArray} of the renderer.
* @param isDisabled Whether the renderer should be set disabled.
* @param override An optional override for the renderer. If null, no override will be set and an
* existing override for this renderer will be cleared.
* @return The updated {@link DefaultTrackSelector.Parameters}.
*/
public static DefaultTrackSelector.Parameters updateParametersWithOverride(
DefaultTrackSelector.Parameters parameters,
int rendererIndex,
TrackGroupArray trackGroupArray,
boolean isDisabled,
@Nullable SelectionOverride override) {
DefaultTrackSelector.ParametersBuilder builder =
parameters
.buildUpon()
.clearSelectionOverrides(rendererIndex)
.setRendererDisabled(rendererIndex, isDisabled);
if (override != null) {
builder.setSelectionOverride(rendererIndex, trackGroupArray, override);
}
return builder.build();
}
/**
* Returns the {@link LoadErrorHandlingPolicy.FallbackOptions} with the tracks of the given {@link
* ExoTrackSelection} and with a single location option indicating that there are no alternative
* locations available.
*
* @param trackSelection The track selection to get the number of total and excluded tracks.
* @return The {@link LoadErrorHandlingPolicy.FallbackOptions} for the given track selection.
*/
public static LoadErrorHandlingPolicy.FallbackOptions createFallbackOptions(
ExoTrackSelection trackSelection) {
long nowMs = SystemClock.elapsedRealtime();
int numberOfTracks = trackSelection.length();
int numberOfExcludedTracks = 0;
for (int i = 0; i < numberOfTracks; i++) {
if (trackSelection.isBlacklisted(i, nowMs)) {
numberOfExcludedTracks++;
}
}
return new LoadErrorHandlingPolicy.FallbackOptions(
/* numberOfLocations= */ 1,
/* numberOfExcludedLocations= */ 0,
numberOfTracks,
numberOfExcludedTracks);
}
}