tree/library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataRenderer.java - platform/external/exoplayer - Git at Google

 /*
  * 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 com.google.android.exoplayer2.metadata;

 import static com.google.android.exoplayer2.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 com.google.android.exoplayer2.BaseRenderer;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.RendererCapabilities;
 import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import org.checkerframework.checker.nullness.compatqual.NullableType;

 /**
  * A renderer for metadata.
  */
 public final class MetadataRenderer extends BaseRenderer implements Callback {

   private static final String TAG = "MetadataRenderer";
   private static final int MSG_INVOKE_RENDERER = 0;
   // TODO: Holding multiple pending metadata objects is temporary mitigation against
   // https://github.com/google/ExoPlayer/issues/1874. It should be removed once this issue has been
   // addressed.
   private static final int MAX_PENDING_METADATA_COUNT = 5;

   private final MetadataDecoderFactory decoderFactory;
   private final MetadataOutput output;
   @Nullable private final Handler outputHandler;
   private final MetadataInputBuffer buffer;
   private final @NullableType Metadata[] pendingMetadata;
   private final long[] pendingMetadataTimestamps;

   private int pendingMetadataIndex;
   private int pendingMetadataCount;
   @Nullable private MetadataDecoder decoder;
   private boolean inputStreamEnded;
   private long subsampleOffsetUs;

   /**
    * @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);
   }

   /**
    * @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) {
     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);
     buffer = new MetadataInputBuffer();
     pendingMetadata = new Metadata[MAX_PENDING_METADATA_COUNT];
     pendingMetadataTimestamps = new long[MAX_PENDING_METADATA_COUNT];
   }

   @Override
   public String getName() {
     return TAG;
   }

   @Override
   @Capabilities
   public int supportsFormat(Format format) {
     if (decoderFactory.supportsFormat(format)) {
       return RendererCapabilities.create(
           format.drmInitData == null ? FORMAT_HANDLED : FORMAT_UNSUPPORTED_DRM);
     } else {
       return RendererCapabilities.create(FORMAT_UNSUPPORTED_TYPE);
     }
   }

   @Override
   protected void onStreamChanged(Format[] formats, long offsetUs) {
     decoder = decoderFactory.createDecoder(formats[0]);
   }

   @Override
   protected void onPositionReset(long positionUs, boolean joining) {
     flushPendingMetadata();
     inputStreamEnded = false;
   }

   @Override
   public void render(long positionUs, long elapsedRealtimeUs) {
     if (!inputStreamEnded && pendingMetadataCount < MAX_PENDING_METADATA_COUNT) {
       buffer.clear();
       FormatHolder formatHolder = getFormatHolder();
       @SampleStream.ReadDataResult int result = readSource(formatHolder, buffer, false);
       if (result == C.RESULT_BUFFER_READ) {
         if (buffer.isEndOfStream()) {
           inputStreamEnded = true;
         } else if (buffer.isDecodeOnly()) {
           // Do nothing. Note this assumes that all metadata buffers can be decoded independently.
           // If we ever need to support a metadata format where this is not the case, we'll need to
           // pass the buffer to the decoder and discard the output.
         } else {
           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(entries);
               int index =
                   (pendingMetadataIndex + pendingMetadataCount) % MAX_PENDING_METADATA_COUNT;
               pendingMetadata[index] = expandedMetadata;
               pendingMetadataTimestamps[index] = buffer.timeUs;
               pendingMetadataCount++;
             }
           }
         }
       } else if (result == C.RESULT_FORMAT_READ) {
         subsampleOffsetUs = Assertions.checkNotNull(formatHolder.format).subsampleOffsetUs;
       }
     }

     if (pendingMetadataCount > 0 && pendingMetadataTimestamps[pendingMetadataIndex] <= positionUs) {
       Metadata metadata = castNonNull(pendingMetadata[pendingMetadataIndex]);
       invokeRenderer(metadata);
       pendingMetadata[pendingMetadataIndex] = null;
       pendingMetadataIndex = (pendingMetadataIndex + 1) % MAX_PENDING_METADATA_COUNT;
       pendingMetadataCount--;
     }
   }

   /**
    * 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() {
     flushPendingMetadata();
     decoder = null;
   }

   @Override
   public boolean isEnded() {
     return inputStreamEnded;
   }

   @Override
   public boolean isReady() {
     return true;
   }

   private void invokeRenderer(Metadata metadata) {
     if (outputHandler != null) {
       outputHandler.obtainMessage(MSG_INVOKE_RENDERER, metadata).sendToTarget();
     } else {
       invokeRendererInternal(metadata);
     }
   }

   private void flushPendingMetadata() {
     Arrays.fill(pendingMetadata, null);
     pendingMetadataIndex = 0;
     pendingMetadataCount = 0;
   }

   @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 invokeRendererInternal(Metadata metadata) {
     output.onMetadata(metadata);
   }

 }
	/*
	* 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 com.google.android.exoplayer2.metadata;

	import static com.google.android.exoplayer2.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 com.google.android.exoplayer2.BaseRenderer;
	import com.google.android.exoplayer2.C;
	import com.google.android.exoplayer2.Format;
	import com.google.android.exoplayer2.FormatHolder;
	import com.google.android.exoplayer2.RendererCapabilities;
	import com.google.android.exoplayer2.source.SampleStream;
	import com.google.android.exoplayer2.util.Assertions;
	import com.google.android.exoplayer2.util.Util;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.List;
	import org.checkerframework.checker.nullness.compatqual.NullableType;

	/**
	* A renderer for metadata.
	*/
	public final class MetadataRenderer extends BaseRenderer implements Callback {

	private static final String TAG = "MetadataRenderer";
	private static final int MSG_INVOKE_RENDERER = 0;
	// TODO: Holding multiple pending metadata objects is temporary mitigation against
	// https://github.com/google/ExoPlayer/issues/1874. It should be removed once this issue has been
	// addressed.
	private static final int MAX_PENDING_METADATA_COUNT = 5;

	private final MetadataDecoderFactory decoderFactory;
	private final MetadataOutput output;
	@Nullable private final Handler outputHandler;
	private final MetadataInputBuffer buffer;
	private final @NullableType Metadata[] pendingMetadata;
	private final long[] pendingMetadataTimestamps;

	private int pendingMetadataIndex;
	private int pendingMetadataCount;
	@Nullable private MetadataDecoder decoder;
	private boolean inputStreamEnded;
	private long subsampleOffsetUs;

	/**
	* @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);
	}

	/**
	* @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) {
	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);
	buffer = new MetadataInputBuffer();
	pendingMetadata = new Metadata[MAX_PENDING_METADATA_COUNT];
	pendingMetadataTimestamps = new long[MAX_PENDING_METADATA_COUNT];
	}

	@Override
	public String getName() {
	return TAG;
	}

	@Override
	@Capabilities
	public int supportsFormat(Format format) {
	if (decoderFactory.supportsFormat(format)) {
	return RendererCapabilities.create(
	format.drmInitData == null ? FORMAT_HANDLED : FORMAT_UNSUPPORTED_DRM);
	} else {
	return RendererCapabilities.create(FORMAT_UNSUPPORTED_TYPE);
	}
	}

	@Override
	protected void onStreamChanged(Format[] formats, long offsetUs) {
	decoder = decoderFactory.createDecoder(formats[0]);
	}

	@Override
	protected void onPositionReset(long positionUs, boolean joining) {
	flushPendingMetadata();
	inputStreamEnded = false;
	}

	@Override
	public void render(long positionUs, long elapsedRealtimeUs) {
	if (!inputStreamEnded && pendingMetadataCount < MAX_PENDING_METADATA_COUNT) {
	buffer.clear();
	FormatHolder formatHolder = getFormatHolder();
	@SampleStream.ReadDataResult int result = readSource(formatHolder, buffer, false);
	if (result == C.RESULT_BUFFER_READ) {
	if (buffer.isEndOfStream()) {
	inputStreamEnded = true;
	} else if (buffer.isDecodeOnly()) {
	// Do nothing. Note this assumes that all metadata buffers can be decoded independently.
	// If we ever need to support a metadata format where this is not the case, we'll need to
	// pass the buffer to the decoder and discard the output.
	} else {
	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(entries);
	int index =
	(pendingMetadataIndex + pendingMetadataCount) % MAX_PENDING_METADATA_COUNT;
	pendingMetadata[index] = expandedMetadata;
	pendingMetadataTimestamps[index] = buffer.timeUs;
	pendingMetadataCount++;
	}
	}
	}
	} else if (result == C.RESULT_FORMAT_READ) {
	subsampleOffsetUs = Assertions.checkNotNull(formatHolder.format).subsampleOffsetUs;
	}
	}

	if (pendingMetadataCount > 0 && pendingMetadataTimestamps[pendingMetadataIndex] <= positionUs) {
	Metadata metadata = castNonNull(pendingMetadata[pendingMetadataIndex]);
	invokeRenderer(metadata);
	pendingMetadata[pendingMetadataIndex] = null;
	pendingMetadataIndex = (pendingMetadataIndex + 1) % MAX_PENDING_METADATA_COUNT;
	pendingMetadataCount--;
	}
	}

	/**
	* 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() {
	flushPendingMetadata();
	decoder = null;
	}

	@Override
	public boolean isEnded() {
	return inputStreamEnded;
	}

	@Override
	public boolean isReady() {
	return true;
	}

	private void invokeRenderer(Metadata metadata) {
	if (outputHandler != null) {
	outputHandler.obtainMessage(MSG_INVOKE_RENDERER, metadata).sendToTarget();
	} else {
	invokeRendererInternal(metadata);
	}
	}

	private void flushPendingMetadata() {
	Arrays.fill(pendingMetadata, null);
	pendingMetadataIndex = 0;
	pendingMetadataCount = 0;
	}

	@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 invokeRendererInternal(Metadata metadata) {
	output.onMetadata(metadata);
	}

	}