InitializationChunk.java
/*
* Copyright (C) 2016 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.source.chunk;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.datasource.DataSource;
import androidx.media3.datasource.DataSourceUtil;
import androidx.media3.datasource.DataSpec;
import androidx.media3.exoplayer.source.chunk.ChunkExtractor.TrackOutputProvider;
import androidx.media3.extractor.DefaultExtractorInput;
import androidx.media3.extractor.Extractor;
import androidx.media3.extractor.ExtractorInput;
import java.io.IOException;
import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
/**
* A {@link Chunk} that uses an {@link Extractor} to decode initialization data for single track.
*/
@UnstableApi
public final class InitializationChunk extends Chunk {
private final ChunkExtractor chunkExtractor;
private @MonotonicNonNull TrackOutputProvider trackOutputProvider;
private long nextLoadPosition;
private volatile boolean loadCanceled;
/**
* @param dataSource The source from which the data should be loaded.
* @param dataSpec Defines the data to be loaded.
* @param trackFormat See {@link #trackFormat}.
* @param trackSelectionReason See {@link #trackSelectionReason}.
* @param trackSelectionData See {@link #trackSelectionData}.
* @param chunkExtractor A wrapped extractor to use for parsing the initialization data.
*/
public InitializationChunk(
DataSource dataSource,
DataSpec dataSpec,
Format trackFormat,
@C.SelectionReason int trackSelectionReason,
@Nullable Object trackSelectionData,
ChunkExtractor chunkExtractor) {
super(
dataSource,
dataSpec,
C.DATA_TYPE_MEDIA_INITIALIZATION,
trackFormat,
trackSelectionReason,
trackSelectionData,
C.TIME_UNSET,
C.TIME_UNSET);
this.chunkExtractor = chunkExtractor;
}
/**
* Initializes the chunk for loading, setting a {@link TrackOutputProvider} for track outputs to
* which formats will be written as they are loaded.
*
* @param trackOutputProvider The {@link TrackOutputProvider} for track outputs to which formats
* will be written as they are loaded.
*/
public void init(TrackOutputProvider trackOutputProvider) {
this.trackOutputProvider = trackOutputProvider;
}
// Loadable implementation.
@Override
public void cancelLoad() {
loadCanceled = true;
}
@SuppressWarnings("NonAtomicVolatileUpdate")
@Override
public void load() throws IOException {
if (nextLoadPosition == 0) {
chunkExtractor.init(
trackOutputProvider, /* startTimeUs= */ C.TIME_UNSET, /* endTimeUs= */ C.TIME_UNSET);
}
try {
// Create and open the input.
DataSpec loadDataSpec = dataSpec.subrange(nextLoadPosition);
ExtractorInput input =
new DefaultExtractorInput(
dataSource, loadDataSpec.position, dataSource.open(loadDataSpec));
// Load and decode the initialization data.
try {
while (!loadCanceled && chunkExtractor.read(input)) {}
} finally {
nextLoadPosition = input.getPosition() - dataSpec.position;
}
} finally {
DataSourceUtil.closeQuietly(dataSource);
}
}
}