android-34/com/google/android/exoplayer2/extractor/flv/FlvExtractor.java - platform/prebuilts/fullsdk/sources - Gitiles

 /*
  * 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.extractor.flv;

 import static java.lang.Math.max;

 import androidx.annotation.IntDef;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.extractor.Extractor;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.extractor.ExtractorOutput;
 import com.google.android.exoplayer2.extractor.ExtractorsFactory;
 import com.google.android.exoplayer2.extractor.IndexSeekMap;
 import com.google.android.exoplayer2.extractor.PositionHolder;
 import com.google.android.exoplayer2.extractor.SeekMap;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import java.io.IOException;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 import org.checkerframework.checker.nullness.qual.RequiresNonNull;

 /** Extracts data from the FLV container format. */
 public final class FlvExtractor implements Extractor {

   /** Factory for {@link FlvExtractor} instances. */
   public static final ExtractorsFactory FACTORY = () -> new Extractor[] {new FlvExtractor()};

   /** Extractor states. */
   @Documented
   @Retention(RetentionPolicy.SOURCE)
   @IntDef({
     STATE_READING_FLV_HEADER,
     STATE_SKIPPING_TO_TAG_HEADER,
     STATE_READING_TAG_HEADER,
     STATE_READING_TAG_DATA
   })
   private @interface States {}

   private static final int STATE_READING_FLV_HEADER = 1;
   private static final int STATE_SKIPPING_TO_TAG_HEADER = 2;
   private static final int STATE_READING_TAG_HEADER = 3;
   private static final int STATE_READING_TAG_DATA = 4;

   // Header sizes.
   private static final int FLV_HEADER_SIZE = 9;
   private static final int FLV_TAG_HEADER_SIZE = 11;

   // Tag types.
   private static final int TAG_TYPE_AUDIO = 8;
   private static final int TAG_TYPE_VIDEO = 9;
   private static final int TAG_TYPE_SCRIPT_DATA = 18;

   // FLV container identifier.
   private static final int FLV_TAG = 0x00464c56;

   private final ParsableByteArray scratch;
   private final ParsableByteArray headerBuffer;
   private final ParsableByteArray tagHeaderBuffer;
   private final ParsableByteArray tagData;
   private final ScriptTagPayloadReader metadataReader;

   private @MonotonicNonNull ExtractorOutput extractorOutput;
   private @States int state;
   private boolean outputFirstSample;
   private long mediaTagTimestampOffsetUs;
   private int bytesToNextTagHeader;
   private int tagType;
   private int tagDataSize;
   private long tagTimestampUs;
   private boolean outputSeekMap;
   private @MonotonicNonNull AudioTagPayloadReader audioReader;
   private @MonotonicNonNull VideoTagPayloadReader videoReader;

   public FlvExtractor() {
     scratch = new ParsableByteArray(4);
     headerBuffer = new ParsableByteArray(FLV_HEADER_SIZE);
     tagHeaderBuffer = new ParsableByteArray(FLV_TAG_HEADER_SIZE);
     tagData = new ParsableByteArray();
     metadataReader = new ScriptTagPayloadReader();
     state = STATE_READING_FLV_HEADER;
   }

   @Override
   public boolean sniff(ExtractorInput input) throws IOException {
     // Check if file starts with "FLV" tag
     input.peekFully(scratch.getData(), 0, 3);
     scratch.setPosition(0);
     if (scratch.readUnsignedInt24() != FLV_TAG) {
       return false;
     }

     // Checking reserved flags are set to 0
     input.peekFully(scratch.getData(), 0, 2);
     scratch.setPosition(0);
     if ((scratch.readUnsignedShort() & 0xFA) != 0) {
       return false;
     }

     // Read data offset
     input.peekFully(scratch.getData(), 0, 4);
     scratch.setPosition(0);
     int dataOffset = scratch.readInt();

     input.resetPeekPosition();
     input.advancePeekPosition(dataOffset);

     // Checking first "previous tag size" is set to 0
     input.peekFully(scratch.getData(), 0, 4);
     scratch.setPosition(0);

     return scratch.readInt() == 0;
   }

   @Override
   public void init(ExtractorOutput output) {
     this.extractorOutput = output;
   }

   @Override
   public void seek(long position, long timeUs) {
     if (position == 0) {
       state = STATE_READING_FLV_HEADER;
       outputFirstSample = false;
     } else {
       state = STATE_READING_TAG_HEADER;
     }
     bytesToNextTagHeader = 0;
   }

   @Override
   public void release() {
     // Do nothing
   }

   @Override
   public int read(ExtractorInput input, PositionHolder seekPosition) throws IOException {
     Assertions.checkStateNotNull(extractorOutput); // Asserts that init has been called.
     while (true) {
       switch (state) {
         case STATE_READING_FLV_HEADER:
           if (!readFlvHeader(input)) {
             return RESULT_END_OF_INPUT;
           }
           break;
         case STATE_SKIPPING_TO_TAG_HEADER:
           skipToTagHeader(input);
           break;
         case STATE_READING_TAG_HEADER:
           if (!readTagHeader(input)) {
             return RESULT_END_OF_INPUT;
           }
           break;
         case STATE_READING_TAG_DATA:
           if (readTagData(input)) {
             return RESULT_CONTINUE;
           }
           break;
         default:
           // Never happens.
           throw new IllegalStateException();
       }
     }
   }

   /**
    * Reads an FLV container header from the provided {@link ExtractorInput}.
    *
    * @param input The {@link ExtractorInput} from which to read.
    * @return True if header was read successfully. False if the end of stream was reached.
    * @throws IOException If an error occurred reading or parsing data from the source.
    */
   @RequiresNonNull("extractorOutput")
   private boolean readFlvHeader(ExtractorInput input) throws IOException {
     if (!input.readFully(headerBuffer.getData(), 0, FLV_HEADER_SIZE, true)) {
       // We've reached the end of the stream.
       return false;
     }

     headerBuffer.setPosition(0);
     headerBuffer.skipBytes(4);
     int flags = headerBuffer.readUnsignedByte();
     boolean hasAudio = (flags & 0x04) != 0;
     boolean hasVideo = (flags & 0x01) != 0;
     if (hasAudio && audioReader == null) {
       audioReader =
           new AudioTagPayloadReader(extractorOutput.track(TAG_TYPE_AUDIO, C.TRACK_TYPE_AUDIO));
     }
     if (hasVideo && videoReader == null) {
       videoReader =
           new VideoTagPayloadReader(extractorOutput.track(TAG_TYPE_VIDEO, C.TRACK_TYPE_VIDEO));
     }
     extractorOutput.endTracks();

     // We need to skip any additional content in the FLV header, plus the 4 byte previous tag size.
     bytesToNextTagHeader = headerBuffer.readInt() - FLV_HEADER_SIZE + 4;
     state = STATE_SKIPPING_TO_TAG_HEADER;
     return true;
   }

   /**
    * Skips over data to reach the next tag header.
    *
    * @param input The {@link ExtractorInput} from which to read.
    * @throws IOException If an error occurred skipping data from the source.
    */
   private void skipToTagHeader(ExtractorInput input) throws IOException {
     input.skipFully(bytesToNextTagHeader);
     bytesToNextTagHeader = 0;
     state = STATE_READING_TAG_HEADER;
   }

   /**
    * Reads a tag header from the provided {@link ExtractorInput}.
    *
    * @param input The {@link ExtractorInput} from which to read.
    * @return True if tag header was read successfully. Otherwise, false.
    * @throws IOException If an error occurred reading or parsing data from the source.
    */
   private boolean readTagHeader(ExtractorInput input) throws IOException {
     if (!input.readFully(tagHeaderBuffer.getData(), 0, FLV_TAG_HEADER_SIZE, true)) {
       // We've reached the end of the stream.
       return false;
     }

     tagHeaderBuffer.setPosition(0);
     tagType = tagHeaderBuffer.readUnsignedByte();
     tagDataSize = tagHeaderBuffer.readUnsignedInt24();
     tagTimestampUs = tagHeaderBuffer.readUnsignedInt24();
     tagTimestampUs = ((tagHeaderBuffer.readUnsignedByte() << 24) | tagTimestampUs) * 1000L;
     tagHeaderBuffer.skipBytes(3); // streamId
     state = STATE_READING_TAG_DATA;
     return true;
   }

   /**
    * Reads the body of a tag from the provided {@link ExtractorInput}.
    *
    * @param input The {@link ExtractorInput} from which to read.
    * @return True if the data was consumed by a reader. False if it was skipped.
    * @throws IOException If an error occurred reading or parsing data from the source.
    */
   @RequiresNonNull("extractorOutput")
   private boolean readTagData(ExtractorInput input) throws IOException {
     boolean wasConsumed = true;
     boolean wasSampleOutput = false;
     long timestampUs = getCurrentTimestampUs();
     if (tagType == TAG_TYPE_AUDIO && audioReader != null) {
       ensureReadyForMediaOutput();
       wasSampleOutput = audioReader.consume(prepareTagData(input), timestampUs);
     } else if (tagType == TAG_TYPE_VIDEO && videoReader != null) {
       ensureReadyForMediaOutput();
       wasSampleOutput = videoReader.consume(prepareTagData(input), timestampUs);
     } else if (tagType == TAG_TYPE_SCRIPT_DATA && !outputSeekMap) {
       wasSampleOutput = metadataReader.consume(prepareTagData(input), timestampUs);
       long durationUs = metadataReader.getDurationUs();
       if (durationUs != C.TIME_UNSET) {
         extractorOutput.seekMap(
             new IndexSeekMap(
                 metadataReader.getKeyFrameTagPositions(),
                 metadataReader.getKeyFrameTimesUs(),
                 durationUs));
         outputSeekMap = true;
       }
     } else {
       input.skipFully(tagDataSize);
       wasConsumed = false;
     }
     if (!outputFirstSample && wasSampleOutput) {
       outputFirstSample = true;
       mediaTagTimestampOffsetUs =
           metadataReader.getDurationUs() == C.TIME_UNSET ? -tagTimestampUs : 0;
     }
     bytesToNextTagHeader = 4; // There's a 4 byte previous tag size before the next header.
     state = STATE_SKIPPING_TO_TAG_HEADER;
     return wasConsumed;
   }

   private ParsableByteArray prepareTagData(ExtractorInput input) throws IOException {
     if (tagDataSize > tagData.capacity()) {
       tagData.reset(new byte[max(tagData.capacity() * 2, tagDataSize)], 0);
     } else {
       tagData.setPosition(0);
     }
     tagData.setLimit(tagDataSize);
     input.readFully(tagData.getData(), 0, tagDataSize);
     return tagData;
   }

   @RequiresNonNull("extractorOutput")
   private void ensureReadyForMediaOutput() {
     if (!outputSeekMap) {
       extractorOutput.seekMap(new SeekMap.Unseekable(C.TIME_UNSET));
       outputSeekMap = true;
     }
   }

   private long getCurrentTimestampUs() {
     return outputFirstSample
         ? (mediaTagTimestampOffsetUs + tagTimestampUs)
         : (metadataReader.getDurationUs() == C.TIME_UNSET ? 0 : tagTimestampUs);
   }
 }
	/*
	* 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.extractor.flv;

	import static java.lang.Math.max;

	import androidx.annotation.IntDef;
	import com.google.android.exoplayer2.C;
	import com.google.android.exoplayer2.extractor.Extractor;
	import com.google.android.exoplayer2.extractor.ExtractorInput;
	import com.google.android.exoplayer2.extractor.ExtractorOutput;
	import com.google.android.exoplayer2.extractor.ExtractorsFactory;
	import com.google.android.exoplayer2.extractor.IndexSeekMap;
	import com.google.android.exoplayer2.extractor.PositionHolder;
	import com.google.android.exoplayer2.extractor.SeekMap;
	import com.google.android.exoplayer2.util.Assertions;
	import com.google.android.exoplayer2.util.ParsableByteArray;
	import java.io.IOException;
	import java.lang.annotation.Documented;
	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
	import org.checkerframework.checker.nullness.qual.RequiresNonNull;

	/** Extracts data from the FLV container format. */
	public final class FlvExtractor implements Extractor {

	/** Factory for {@link FlvExtractor} instances. */
	public static final ExtractorsFactory FACTORY = () -> new Extractor[] {new FlvExtractor()};

	/** Extractor states. */
	@Documented
	@Retention(RetentionPolicy.SOURCE)
	@IntDef({
	STATE_READING_FLV_HEADER,
	STATE_SKIPPING_TO_TAG_HEADER,
	STATE_READING_TAG_HEADER,
	STATE_READING_TAG_DATA
	})
	private @interface States {}

	private static final int STATE_READING_FLV_HEADER = 1;
	private static final int STATE_SKIPPING_TO_TAG_HEADER = 2;
	private static final int STATE_READING_TAG_HEADER = 3;
	private static final int STATE_READING_TAG_DATA = 4;

	// Header sizes.
	private static final int FLV_HEADER_SIZE = 9;
	private static final int FLV_TAG_HEADER_SIZE = 11;

	// Tag types.
	private static final int TAG_TYPE_AUDIO = 8;
	private static final int TAG_TYPE_VIDEO = 9;
	private static final int TAG_TYPE_SCRIPT_DATA = 18;

	// FLV container identifier.
	private static final int FLV_TAG = 0x00464c56;

	private final ParsableByteArray scratch;
	private final ParsableByteArray headerBuffer;
	private final ParsableByteArray tagHeaderBuffer;
	private final ParsableByteArray tagData;
	private final ScriptTagPayloadReader metadataReader;

	private @MonotonicNonNull ExtractorOutput extractorOutput;
	private @States int state;
	private boolean outputFirstSample;
	private long mediaTagTimestampOffsetUs;
	private int bytesToNextTagHeader;
	private int tagType;
	private int tagDataSize;
	private long tagTimestampUs;
	private boolean outputSeekMap;
	private @MonotonicNonNull AudioTagPayloadReader audioReader;
	private @MonotonicNonNull VideoTagPayloadReader videoReader;

	public FlvExtractor() {
	scratch = new ParsableByteArray(4);
	headerBuffer = new ParsableByteArray(FLV_HEADER_SIZE);
	tagHeaderBuffer = new ParsableByteArray(FLV_TAG_HEADER_SIZE);
	tagData = new ParsableByteArray();
	metadataReader = new ScriptTagPayloadReader();
	state = STATE_READING_FLV_HEADER;
	}

	@Override
	public boolean sniff(ExtractorInput input) throws IOException {
	// Check if file starts with "FLV" tag
	input.peekFully(scratch.getData(), 0, 3);
	scratch.setPosition(0);
	if (scratch.readUnsignedInt24() != FLV_TAG) {
	return false;
	}

	// Checking reserved flags are set to 0
	input.peekFully(scratch.getData(), 0, 2);
	scratch.setPosition(0);
	if ((scratch.readUnsignedShort() & 0xFA) != 0) {
	return false;
	}

	// Read data offset
	input.peekFully(scratch.getData(), 0, 4);
	scratch.setPosition(0);
	int dataOffset = scratch.readInt();

	input.resetPeekPosition();
	input.advancePeekPosition(dataOffset);

	// Checking first "previous tag size" is set to 0
	input.peekFully(scratch.getData(), 0, 4);
	scratch.setPosition(0);

	return scratch.readInt() == 0;
	}

	@Override
	public void init(ExtractorOutput output) {
	this.extractorOutput = output;
	}

	@Override
	public void seek(long position, long timeUs) {
	if (position == 0) {
	state = STATE_READING_FLV_HEADER;
	outputFirstSample = false;
	} else {
	state = STATE_READING_TAG_HEADER;
	}
	bytesToNextTagHeader = 0;
	}

	@Override
	public void release() {
	// Do nothing
	}

	@Override
	public int read(ExtractorInput input, PositionHolder seekPosition) throws IOException {
	Assertions.checkStateNotNull(extractorOutput); // Asserts that init has been called.
	while (true) {
	switch (state) {
	case STATE_READING_FLV_HEADER:
	if (!readFlvHeader(input)) {
	return RESULT_END_OF_INPUT;
	}
	break;
	case STATE_SKIPPING_TO_TAG_HEADER:
	skipToTagHeader(input);
	break;
	case STATE_READING_TAG_HEADER:
	if (!readTagHeader(input)) {
	return RESULT_END_OF_INPUT;
	}
	break;
	case STATE_READING_TAG_DATA:
	if (readTagData(input)) {
	return RESULT_CONTINUE;
	}
	break;
	default:
	// Never happens.
	throw new IllegalStateException();
	}
	}
	}

	/**
	* Reads an FLV container header from the provided {@link ExtractorInput}.
	*
	* @param input The {@link ExtractorInput} from which to read.
	* @return True if header was read successfully. False if the end of stream was reached.
	* @throws IOException If an error occurred reading or parsing data from the source.
	*/
	@RequiresNonNull("extractorOutput")
	private boolean readFlvHeader(ExtractorInput input) throws IOException {
	if (!input.readFully(headerBuffer.getData(), 0, FLV_HEADER_SIZE, true)) {
	// We've reached the end of the stream.
	return false;
	}

	headerBuffer.setPosition(0);
	headerBuffer.skipBytes(4);
	int flags = headerBuffer.readUnsignedByte();
	boolean hasAudio = (flags & 0x04) != 0;
	boolean hasVideo = (flags & 0x01) != 0;
	if (hasAudio && audioReader == null) {
	audioReader =
	new AudioTagPayloadReader(extractorOutput.track(TAG_TYPE_AUDIO, C.TRACK_TYPE_AUDIO));
	}
	if (hasVideo && videoReader == null) {
	videoReader =
	new VideoTagPayloadReader(extractorOutput.track(TAG_TYPE_VIDEO, C.TRACK_TYPE_VIDEO));
	}
	extractorOutput.endTracks();

	// We need to skip any additional content in the FLV header, plus the 4 byte previous tag size.
	bytesToNextTagHeader = headerBuffer.readInt() - FLV_HEADER_SIZE + 4;
	state = STATE_SKIPPING_TO_TAG_HEADER;
	return true;
	}

	/**
	* Skips over data to reach the next tag header.
	*
	* @param input The {@link ExtractorInput} from which to read.
	* @throws IOException If an error occurred skipping data from the source.
	*/
	private void skipToTagHeader(ExtractorInput input) throws IOException {
	input.skipFully(bytesToNextTagHeader);
	bytesToNextTagHeader = 0;
	state = STATE_READING_TAG_HEADER;
	}

	/**
	* Reads a tag header from the provided {@link ExtractorInput}.
	*
	* @param input The {@link ExtractorInput} from which to read.
	* @return True if tag header was read successfully. Otherwise, false.
	* @throws IOException If an error occurred reading or parsing data from the source.
	*/
	private boolean readTagHeader(ExtractorInput input) throws IOException {
	if (!input.readFully(tagHeaderBuffer.getData(), 0, FLV_TAG_HEADER_SIZE, true)) {
	// We've reached the end of the stream.
	return false;
	}

	tagHeaderBuffer.setPosition(0);
	tagType = tagHeaderBuffer.readUnsignedByte();
	tagDataSize = tagHeaderBuffer.readUnsignedInt24();
	tagTimestampUs = tagHeaderBuffer.readUnsignedInt24();
	tagTimestampUs = ((tagHeaderBuffer.readUnsignedByte() << 24) \| tagTimestampUs) * 1000L;
	tagHeaderBuffer.skipBytes(3); // streamId
	state = STATE_READING_TAG_DATA;
	return true;
	}

	/**
	* Reads the body of a tag from the provided {@link ExtractorInput}.
	*
	* @param input The {@link ExtractorInput} from which to read.
	* @return True if the data was consumed by a reader. False if it was skipped.
	* @throws IOException If an error occurred reading or parsing data from the source.
	*/
	@RequiresNonNull("extractorOutput")
	private boolean readTagData(ExtractorInput input) throws IOException {
	boolean wasConsumed = true;
	boolean wasSampleOutput = false;
	long timestampUs = getCurrentTimestampUs();
	if (tagType == TAG_TYPE_AUDIO && audioReader != null) {
	ensureReadyForMediaOutput();
	wasSampleOutput = audioReader.consume(prepareTagData(input), timestampUs);
	} else if (tagType == TAG_TYPE_VIDEO && videoReader != null) {
	ensureReadyForMediaOutput();
	wasSampleOutput = videoReader.consume(prepareTagData(input), timestampUs);
	} else if (tagType == TAG_TYPE_SCRIPT_DATA && !outputSeekMap) {
	wasSampleOutput = metadataReader.consume(prepareTagData(input), timestampUs);
	long durationUs = metadataReader.getDurationUs();
	if (durationUs != C.TIME_UNSET) {
	extractorOutput.seekMap(
	new IndexSeekMap(
	metadataReader.getKeyFrameTagPositions(),
	metadataReader.getKeyFrameTimesUs(),
	durationUs));
	outputSeekMap = true;
	}
	} else {
	input.skipFully(tagDataSize);
	wasConsumed = false;
	}
	if (!outputFirstSample && wasSampleOutput) {
	outputFirstSample = true;
	mediaTagTimestampOffsetUs =
	metadataReader.getDurationUs() == C.TIME_UNSET ? -tagTimestampUs : 0;
	}
	bytesToNextTagHeader = 4; // There's a 4 byte previous tag size before the next header.
	state = STATE_SKIPPING_TO_TAG_HEADER;
	return wasConsumed;
	}

	private ParsableByteArray prepareTagData(ExtractorInput input) throws IOException {
	if (tagDataSize > tagData.capacity()) {
	tagData.reset(new byte[max(tagData.capacity() * 2, tagDataSize)], 0);
	} else {
	tagData.setPosition(0);
	}
	tagData.setLimit(tagDataSize);
	input.readFully(tagData.getData(), 0, tagDataSize);
	return tagData;
	}

	@RequiresNonNull("extractorOutput")
	private void ensureReadyForMediaOutput() {
	if (!outputSeekMap) {
	extractorOutput.seekMap(new SeekMap.Unseekable(C.TIME_UNSET));
	outputSeekMap = true;
	}
	}

	private long getCurrentTimestampUs() {
	return outputFirstSample
	? (mediaTagTimestampOffsetUs + tagTimestampUs)
	: (metadataReader.getDurationUs() == C.TIME_UNSET ? 0 : tagTimestampUs);
	}
	}