/*
* 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.metadata;
import static androidx.media3.common.util.Assertions.checkState;
import static androidx.media3.common.util.Util.castNonNull;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.Looper;
import android.os.Message;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.Metadata;
import androidx.media3.common.util.Assertions;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.common.util.Util;
import androidx.media3.exoplayer.BaseRenderer;
import androidx.media3.exoplayer.FormatHolder;
import androidx.media3.exoplayer.RendererCapabilities;
import androidx.media3.exoplayer.source.MediaSource;
import androidx.media3.exoplayer.source.SampleStream.ReadDataResult;
import androidx.media3.extractor.metadata.MetadataDecoder;
import androidx.media3.extractor.metadata.MetadataInputBuffer;
import java.util.ArrayList;
import java.util.List;
import org.checkerframework.dataflow.qual.SideEffectFree;
/**
* A renderer for metadata.
*
* <p>The renderer can be configured to render metadata as soon as they are available using {@link
* #MetadataRenderer(MetadataOutput, Looper, MetadataDecoderFactory, boolean)}.
*/
@UnstableApi
public final class MetadataRenderer extends BaseRenderer implements Callback {
private static final String TAG = "MetadataRenderer";
private static final int MSG_INVOKE_RENDERER = 0;
private final MetadataDecoderFactory decoderFactory;
private final MetadataOutput output;
@Nullable private final Handler outputHandler;
private final MetadataInputBuffer buffer;
private final boolean outputMetadataEarly;
@Nullable private MetadataDecoder decoder;
private boolean inputStreamEnded;
private boolean outputStreamEnded;
private long subsampleOffsetUs;
@Nullable private Metadata pendingMetadata;
private long outputStreamOffsetUs;
/**
* Creates an instance that uses {@link MetadataDecoderFactory#DEFAULT} to create {@link
* MetadataDecoder} instances.
*
* @param output The output.
* @param outputLooper The looper associated with the thread on which the output should be called.
* If the output makes use of standard Android UI components, then this should normally be the
* looper associated with the application's main thread, which can be obtained using {@link
* android.app.Activity#getMainLooper()}. Null may be passed if the output should be called
* directly on the player's internal rendering thread.
*/
public MetadataRenderer(MetadataOutput output, @Nullable Looper outputLooper) {
this(output, outputLooper, MetadataDecoderFactory.DEFAULT);
}
/**
* Creates an instance.
*
* @param output The output.
* @param outputLooper The looper associated with the thread on which the output should be called.
* If the output makes use of standard Android UI components, then this should normally be the
* looper associated with the application's main thread, which can be obtained using {@link
* android.app.Activity#getMainLooper()}. Null may be passed if the output should be called
* directly on the player's internal rendering thread.
* @param decoderFactory A factory from which to obtain {@link MetadataDecoder} instances.
*/
public MetadataRenderer(
MetadataOutput output, @Nullable Looper outputLooper, MetadataDecoderFactory decoderFactory) {
this(output, outputLooper, decoderFactory, /* outputMetadataEarly= */ false);
}
/**
* Creates an instance.
*
* @param output The output.
* @param outputLooper The looper associated with the thread on which the output should be called.
* If the output makes use of standard Android UI components, then this should normally be the
* looper associated with the application's main thread, which can be obtained using {@link
* android.app.Activity#getMainLooper()}. Null may be passed if the output should be called
* directly on the player's internal rendering thread.
* @param decoderFactory A factory from which to obtain {@link MetadataDecoder} instances.
* @param outputMetadataEarly Whether the renderer outputs metadata early. When {@code true},
* {@link #render} will output metadata as soon as they are available to the renderer,
* otherwise {@link #render} will output metadata in sync with the rendering position.
*/
public MetadataRenderer(
MetadataOutput output,
@Nullable Looper outputLooper,
MetadataDecoderFactory decoderFactory,
boolean outputMetadataEarly) {
super(C.TRACK_TYPE_METADATA);
this.output = Assertions.checkNotNull(output);
this.outputHandler =
outputLooper == null ? null : Util.createHandler(outputLooper, /* callback= */ this);
this.decoderFactory = Assertions.checkNotNull(decoderFactory);
this.outputMetadataEarly = outputMetadataEarly;
buffer = new MetadataInputBuffer();
outputStreamOffsetUs = C.TIME_UNSET;
}
@Override
public String getName() {
return TAG;
}
@Override
public @Capabilities int supportsFormat(Format format) {
if (decoderFactory.supportsFormat(format)) {
return RendererCapabilities.create(
format.cryptoType == C.CRYPTO_TYPE_NONE ? C.FORMAT_HANDLED : C.FORMAT_UNSUPPORTED_DRM);
} else {
return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_TYPE);
}
}
@Override
protected void onStreamChanged(
Format[] formats,
long startPositionUs,
long offsetUs,
MediaSource.MediaPeriodId mediaPeriodId) {
decoder = decoderFactory.createDecoder(formats[0]);
if (pendingMetadata != null) {
pendingMetadata =
pendingMetadata.copyWithPresentationTimeUs(
pendingMetadata.presentationTimeUs + outputStreamOffsetUs - offsetUs);
}
outputStreamOffsetUs = offsetUs;
}
@Override
protected void onPositionReset(long positionUs, boolean joining) {
pendingMetadata = null;
inputStreamEnded = false;
outputStreamEnded = false;
}
@Override
public void render(long positionUs, long elapsedRealtimeUs) {
boolean working = true;
while (working) {
readMetadata();
working = outputMetadata(positionUs);
}
}
/**
* Iterates through {@code metadata.entries} and checks each one to see if contains wrapped
* metadata. If it does, then we recursively decode the wrapped metadata. If it doesn't (recursion
* base-case), we add the {@link Metadata.Entry} to {@code decodedEntries} (output parameter).
*/
private void decodeWrappedMetadata(Metadata metadata, List<Metadata.Entry> decodedEntries) {
for (int i = 0; i < metadata.length(); i++) {
@Nullable Format wrappedMetadataFormat = metadata.get(i).getWrappedMetadataFormat();
if (wrappedMetadataFormat != null && decoderFactory.supportsFormat(wrappedMetadataFormat)) {
MetadataDecoder wrappedMetadataDecoder =
decoderFactory.createDecoder(wrappedMetadataFormat);
// wrappedMetadataFormat != null so wrappedMetadataBytes must be non-null too.
byte[] wrappedMetadataBytes =
Assertions.checkNotNull(metadata.get(i).getWrappedMetadataBytes());
buffer.clear();
buffer.ensureSpaceForWrite(wrappedMetadataBytes.length);
castNonNull(buffer.data).put(wrappedMetadataBytes);
buffer.flip();
@Nullable Metadata innerMetadata = wrappedMetadataDecoder.decode(buffer);
if (innerMetadata != null) {
// The decoding succeeded, so we'll try another level of unwrapping.
decodeWrappedMetadata(innerMetadata, decodedEntries);
}
} else {
// Entry doesn't contain any wrapped metadata, so output it directly.
decodedEntries.add(metadata.get(i));
}
}
}
@Override
protected void onDisabled() {
pendingMetadata = null;
decoder = null;
outputStreamOffsetUs = C.TIME_UNSET;
}
@Override
public boolean isEnded() {
return outputStreamEnded;
}
@Override
public boolean isReady() {
return true;
}
@Override
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MSG_INVOKE_RENDERER:
invokeRendererInternal((Metadata) msg.obj);
return true;
default:
// Should never happen.
throw new IllegalStateException();
}
}
private void readMetadata() {
if (!inputStreamEnded && pendingMetadata == null) {
buffer.clear();
FormatHolder formatHolder = getFormatHolder();
@ReadDataResult int result = readSource(formatHolder, buffer, /* readFlags= */ 0);
if (result == C.RESULT_BUFFER_READ) {
if (buffer.isEndOfStream()) {
inputStreamEnded = true;
} else if (buffer.timeUs >= getLastResetPositionUs()) {
// Ignore metadata before start position.
buffer.subsampleOffsetUs = subsampleOffsetUs;
buffer.flip();
@Nullable Metadata metadata = castNonNull(decoder).decode(buffer);
if (metadata != null) {
List<Metadata.Entry> entries = new ArrayList<>(metadata.length());
decodeWrappedMetadata(metadata, entries);
if (!entries.isEmpty()) {
Metadata expandedMetadata =
new Metadata(getPresentationTimeUs(buffer.timeUs), entries);
pendingMetadata = expandedMetadata;
}
}
}
} else if (result == C.RESULT_FORMAT_READ) {
subsampleOffsetUs = Assertions.checkNotNull(formatHolder.format).subsampleOffsetUs;
}
}
}
private boolean outputMetadata(long positionUs) {
boolean didOutput = false;
if (pendingMetadata != null
&& (outputMetadataEarly
|| pendingMetadata.presentationTimeUs <= getPresentationTimeUs(positionUs))) {
invokeRenderer(pendingMetadata);
pendingMetadata = null;
didOutput = true;
}
if (inputStreamEnded && pendingMetadata == null) {
outputStreamEnded = true;
}
return didOutput;
}
private void invokeRenderer(Metadata metadata) {
if (outputHandler != null) {
outputHandler.obtainMessage(MSG_INVOKE_RENDERER, metadata).sendToTarget();
} else {
invokeRendererInternal(metadata);
}
}
private void invokeRendererInternal(Metadata metadata) {
output.onMetadata(metadata);
}
@SideEffectFree
private long getPresentationTimeUs(long positionUs) {
checkState(positionUs != C.TIME_UNSET);
checkState(outputStreamOffsetUs != C.TIME_UNSET);
return positionUs - outputStreamOffsetUs;
}
}