diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/PsExtractor.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/PsExtractor.java | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/PsExtractor.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/PsExtractor.java new file mode 100644 index 0000000000..8dcccbe459 --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/PsExtractor.java @@ -0,0 +1,397 @@ +/* + * 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 org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts; + +import android.util.SparseArray; +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.ParserException; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.Extractor; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorInput; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorOutput; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorsFactory; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.PositionHolder; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.SeekMap; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableBitArray; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.TimestampAdjuster; +import java.io.IOException; + +/** + * Extracts data from the MPEG-2 PS container format. + */ +public final class PsExtractor implements Extractor { + + /** Factory for {@link PsExtractor} instances. */ + public static final ExtractorsFactory FACTORY = () -> new Extractor[] {new PsExtractor()}; + + /* package */ static final int PACK_START_CODE = 0x000001BA; + /* package */ static final int SYSTEM_HEADER_START_CODE = 0x000001BB; + /* package */ static final int PACKET_START_CODE_PREFIX = 0x000001; + /* package */ static final int MPEG_PROGRAM_END_CODE = 0x000001B9; + private static final int MAX_STREAM_ID_PLUS_ONE = 0x100; + + // Max search length for first audio and video track in input data. + private static final long MAX_SEARCH_LENGTH = 1024 * 1024; + // Max search length for additional audio and video tracks in input data after at least one audio + // and video track has been found. + private static final long MAX_SEARCH_LENGTH_AFTER_AUDIO_AND_VIDEO_FOUND = 8 * 1024; + + public static final int PRIVATE_STREAM_1 = 0xBD; + public static final int AUDIO_STREAM = 0xC0; + public static final int AUDIO_STREAM_MASK = 0xE0; + public static final int VIDEO_STREAM = 0xE0; + public static final int VIDEO_STREAM_MASK = 0xF0; + + private final TimestampAdjuster timestampAdjuster; + private final SparseArray<PesReader> psPayloadReaders; // Indexed by pid + private final ParsableByteArray psPacketBuffer; + private final PsDurationReader durationReader; + + private boolean foundAllTracks; + private boolean foundAudioTrack; + private boolean foundVideoTrack; + private long lastTrackPosition; + + // Accessed only by the loading thread. + private PsBinarySearchSeeker psBinarySearchSeeker; + private ExtractorOutput output; + private boolean hasOutputSeekMap; + + public PsExtractor() { + this(new TimestampAdjuster(0)); + } + + public PsExtractor(TimestampAdjuster timestampAdjuster) { + this.timestampAdjuster = timestampAdjuster; + psPacketBuffer = new ParsableByteArray(4096); + psPayloadReaders = new SparseArray<>(); + durationReader = new PsDurationReader(); + } + + // Extractor implementation. + + @Override + public boolean sniff(ExtractorInput input) throws IOException, InterruptedException { + byte[] scratch = new byte[14]; + input.peekFully(scratch, 0, 14); + + // Verify the PACK_START_CODE for the first 4 bytes + if (PACK_START_CODE != (((scratch[0] & 0xFF) << 24) | ((scratch[1] & 0xFF) << 16) + | ((scratch[2] & 0xFF) << 8) | (scratch[3] & 0xFF))) { + return false; + } + // Verify the 01xxx1xx marker on the 5th byte + if ((scratch[4] & 0xC4) != 0x44) { + return false; + } + // Verify the xxxxx1xx marker on the 7th byte + if ((scratch[6] & 0x04) != 0x04) { + return false; + } + // Verify the xxxxx1xx marker on the 9th byte + if ((scratch[8] & 0x04) != 0x04) { + return false; + } + // Verify the xxxxxxx1 marker on the 10th byte + if ((scratch[9] & 0x01) != 0x01) { + return false; + } + // Verify the xxxxxx11 marker on the 13th byte + if ((scratch[12] & 0x03) != 0x03) { + return false; + } + // Read the stuffing length from the 14th byte (last 3 bits) + int packStuffingLength = scratch[13] & 0x07; + input.advancePeekPosition(packStuffingLength); + // Now check that the next 3 bytes are the beginning of an MPEG start code + input.peekFully(scratch, 0, 3); + return (PACKET_START_CODE_PREFIX == (((scratch[0] & 0xFF) << 16) | ((scratch[1] & 0xFF) << 8) + | (scratch[2] & 0xFF))); + } + + @Override + public void init(ExtractorOutput output) { + this.output = output; + } + + @Override + public void seek(long position, long timeUs) { + boolean hasNotEncounteredFirstTimestamp = + timestampAdjuster.getTimestampOffsetUs() == C.TIME_UNSET; + if (hasNotEncounteredFirstTimestamp + || (timestampAdjuster.getFirstSampleTimestampUs() != 0 + && timestampAdjuster.getFirstSampleTimestampUs() != timeUs)) { + // - If the timestamp adjuster in the PS stream has not encountered any sample, it's going to + // treat the first timestamp encountered as sample time 0, which is incorrect. In this case, + // we have to set the first sample timestamp manually. + // - If the timestamp adjuster has its timestamp set manually before, and now we seek to a + // different position, we need to set the first sample timestamp manually again. + timestampAdjuster.reset(); + timestampAdjuster.setFirstSampleTimestampUs(timeUs); + } + + if (psBinarySearchSeeker != null) { + psBinarySearchSeeker.setSeekTargetUs(timeUs); + } + for (int i = 0; i < psPayloadReaders.size(); i++) { + psPayloadReaders.valueAt(i).seek(); + } + } + + @Override + public void release() { + // Do nothing + } + + @Override + public int read(ExtractorInput input, PositionHolder seekPosition) + throws IOException, InterruptedException { + + long inputLength = input.getLength(); + boolean canReadDuration = inputLength != C.LENGTH_UNSET; + if (canReadDuration && !durationReader.isDurationReadFinished()) { + return durationReader.readDuration(input, seekPosition); + } + maybeOutputSeekMap(inputLength); + if (psBinarySearchSeeker != null && psBinarySearchSeeker.isSeeking()) { + return psBinarySearchSeeker.handlePendingSeek(input, seekPosition); + } + + input.resetPeekPosition(); + long peekBytesLeft = + inputLength != C.LENGTH_UNSET ? inputLength - input.getPeekPosition() : C.LENGTH_UNSET; + if (peekBytesLeft != C.LENGTH_UNSET && peekBytesLeft < 4) { + return RESULT_END_OF_INPUT; + } + // First peek and check what type of start code is next. + if (!input.peekFully(psPacketBuffer.data, 0, 4, true)) { + return RESULT_END_OF_INPUT; + } + + psPacketBuffer.setPosition(0); + int nextStartCode = psPacketBuffer.readInt(); + if (nextStartCode == MPEG_PROGRAM_END_CODE) { + return RESULT_END_OF_INPUT; + } else if (nextStartCode == PACK_START_CODE) { + // Now peek the rest of the pack_header. + input.peekFully(psPacketBuffer.data, 0, 10); + + // We only care about the pack_stuffing_length in here, skip the first 77 bits. + psPacketBuffer.setPosition(9); + + // Last 3 bits is the length. + int packStuffingLength = psPacketBuffer.readUnsignedByte() & 0x07; + + // Now skip the stuffing and the pack header. + input.skipFully(packStuffingLength + 14); + return RESULT_CONTINUE; + } else if (nextStartCode == SYSTEM_HEADER_START_CODE) { + // We just skip all this, but we need to get the length first. + input.peekFully(psPacketBuffer.data, 0, 2); + + // Length is the next 2 bytes. + psPacketBuffer.setPosition(0); + int systemHeaderLength = psPacketBuffer.readUnsignedShort(); + input.skipFully(systemHeaderLength + 6); + return RESULT_CONTINUE; + } else if (((nextStartCode & 0xFFFFFF00) >> 8) != PACKET_START_CODE_PREFIX) { + input.skipFully(1); // Skip bytes until we see a valid start code again. + return RESULT_CONTINUE; + } + + // We're at the start of a regular PES packet now. + // Get the stream ID off the last byte of the start code. + int streamId = nextStartCode & 0xFF; + + // Check to see if we have this one in our map yet, and if not, then add it. + PesReader payloadReader = psPayloadReaders.get(streamId); + if (!foundAllTracks) { + if (payloadReader == null) { + ElementaryStreamReader elementaryStreamReader = null; + if (streamId == PRIVATE_STREAM_1) { + // Private stream, used for AC3 audio. + // NOTE: This may need further parsing to determine if its DTS, but that's likely only + // valid for DVDs. + elementaryStreamReader = new Ac3Reader(); + foundAudioTrack = true; + lastTrackPosition = input.getPosition(); + } else if ((streamId & AUDIO_STREAM_MASK) == AUDIO_STREAM) { + elementaryStreamReader = new MpegAudioReader(); + foundAudioTrack = true; + lastTrackPosition = input.getPosition(); + } else if ((streamId & VIDEO_STREAM_MASK) == VIDEO_STREAM) { + elementaryStreamReader = new H262Reader(); + foundVideoTrack = true; + lastTrackPosition = input.getPosition(); + } + if (elementaryStreamReader != null) { + TrackIdGenerator idGenerator = new TrackIdGenerator(streamId, MAX_STREAM_ID_PLUS_ONE); + elementaryStreamReader.createTracks(output, idGenerator); + payloadReader = new PesReader(elementaryStreamReader, timestampAdjuster); + psPayloadReaders.put(streamId, payloadReader); + } + } + long maxSearchPosition = + foundAudioTrack && foundVideoTrack + ? lastTrackPosition + MAX_SEARCH_LENGTH_AFTER_AUDIO_AND_VIDEO_FOUND + : MAX_SEARCH_LENGTH; + if (input.getPosition() > maxSearchPosition) { + foundAllTracks = true; + output.endTracks(); + } + } + + // The next 2 bytes are the length. Once we have that we can consume the complete packet. + input.peekFully(psPacketBuffer.data, 0, 2); + psPacketBuffer.setPosition(0); + int payloadLength = psPacketBuffer.readUnsignedShort(); + int pesLength = payloadLength + 6; + + if (payloadReader == null) { + // Just skip this data. + input.skipFully(pesLength); + } else { + psPacketBuffer.reset(pesLength); + // Read the whole packet and the header for consumption. + input.readFully(psPacketBuffer.data, 0, pesLength); + psPacketBuffer.setPosition(6); + payloadReader.consume(psPacketBuffer); + psPacketBuffer.setLimit(psPacketBuffer.capacity()); + } + + return RESULT_CONTINUE; + } + + // Internals. + + private void maybeOutputSeekMap(long inputLength) { + if (!hasOutputSeekMap) { + hasOutputSeekMap = true; + if (durationReader.getDurationUs() != C.TIME_UNSET) { + psBinarySearchSeeker = + new PsBinarySearchSeeker( + durationReader.getScrTimestampAdjuster(), + durationReader.getDurationUs(), + inputLength); + output.seekMap(psBinarySearchSeeker.getSeekMap()); + } else { + output.seekMap(new SeekMap.Unseekable(durationReader.getDurationUs())); + } + } + } + + /** + * Parses PES packet data and extracts samples. + */ + private static final class PesReader { + + private static final int PES_SCRATCH_SIZE = 64; + + private final ElementaryStreamReader pesPayloadReader; + private final TimestampAdjuster timestampAdjuster; + private final ParsableBitArray pesScratch; + + private boolean ptsFlag; + private boolean dtsFlag; + private boolean seenFirstDts; + private int extendedHeaderLength; + private long timeUs; + + public PesReader(ElementaryStreamReader pesPayloadReader, TimestampAdjuster timestampAdjuster) { + this.pesPayloadReader = pesPayloadReader; + this.timestampAdjuster = timestampAdjuster; + pesScratch = new ParsableBitArray(new byte[PES_SCRATCH_SIZE]); + } + + /** + * Notifies the reader that a seek has occurred. + * <p> + * Following a call to this method, the data passed to the next invocation of + * {@link #consume(ParsableByteArray)} will not be a continuation of the data that was + * previously passed. Hence the reader should reset any internal state. + */ + public void seek() { + seenFirstDts = false; + pesPayloadReader.seek(); + } + + /** + * Consumes the payload of a PS packet. + * + * @param data The PES packet. The position will be set to the start of the payload. + * @throws ParserException If the payload could not be parsed. + */ + public void consume(ParsableByteArray data) throws ParserException { + data.readBytes(pesScratch.data, 0, 3); + pesScratch.setPosition(0); + parseHeader(); + data.readBytes(pesScratch.data, 0, extendedHeaderLength); + pesScratch.setPosition(0); + parseHeaderExtension(); + pesPayloadReader.packetStarted(timeUs, TsPayloadReader.FLAG_DATA_ALIGNMENT_INDICATOR); + pesPayloadReader.consume(data); + // We always have complete PES packets with program stream. + pesPayloadReader.packetFinished(); + } + + private void parseHeader() { + // Note: see ISO/IEC 13818-1, section 2.4.3.6 for detailed information on the format of + // the header. + // First 8 bits are skipped: '10' (2), PES_scrambling_control (2), PES_priority (1), + // data_alignment_indicator (1), copyright (1), original_or_copy (1) + pesScratch.skipBits(8); + ptsFlag = pesScratch.readBit(); + dtsFlag = pesScratch.readBit(); + // ESCR_flag (1), ES_rate_flag (1), DSM_trick_mode_flag (1), + // additional_copy_info_flag (1), PES_CRC_flag (1), PES_extension_flag (1) + pesScratch.skipBits(6); + extendedHeaderLength = pesScratch.readBits(8); + } + + private void parseHeaderExtension() { + timeUs = 0; + if (ptsFlag) { + pesScratch.skipBits(4); // '0010' or '0011' + long pts = (long) pesScratch.readBits(3) << 30; + pesScratch.skipBits(1); // marker_bit + pts |= pesScratch.readBits(15) << 15; + pesScratch.skipBits(1); // marker_bit + pts |= pesScratch.readBits(15); + pesScratch.skipBits(1); // marker_bit + if (!seenFirstDts && dtsFlag) { + pesScratch.skipBits(4); // '0011' + long dts = (long) pesScratch.readBits(3) << 30; + pesScratch.skipBits(1); // marker_bit + dts |= pesScratch.readBits(15) << 15; + pesScratch.skipBits(1); // marker_bit + dts |= pesScratch.readBits(15); + pesScratch.skipBits(1); // marker_bit + // Subsequent PES packets may have earlier presentation timestamps than this one, but they + // should all be greater than or equal to this packet's decode timestamp. We feed the + // decode timestamp to the adjuster here so that in the case that this is the first to be + // fed, the adjuster will be able to compute an offset to apply such that the adjusted + // presentation timestamps of all future packets are non-negative. + timestampAdjuster.adjustTsTimestamp(dts); + seenFirstDts = true; + } + timeUs = timestampAdjuster.adjustTsTimestamp(pts); + } + } + + } + +} |