diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/H264Reader.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/H264Reader.java | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/H264Reader.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/H264Reader.java new file mode 100644 index 0000000000..164c115159 --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/ts/H264Reader.java @@ -0,0 +1,567 @@ +/* + * 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 static org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.FLAG_RANDOM_ACCESS_INDICATOR; + +import android.util.SparseArray; +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.Format; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorOutput; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.TrackOutput; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ts.TsPayloadReader.TrackIdGenerator; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.CodecSpecificDataUtil; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.MimeTypes; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.NalUnitUtil; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.NalUnitUtil.SpsData; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableNalUnitBitArray; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; + +/** + * Parses a continuous H264 byte stream and extracts individual frames. + */ +public final class H264Reader implements ElementaryStreamReader { + + private static final int NAL_UNIT_TYPE_SEI = 6; // Supplemental enhancement information + private static final int NAL_UNIT_TYPE_SPS = 7; // Sequence parameter set + private static final int NAL_UNIT_TYPE_PPS = 8; // Picture parameter set + + private final SeiReader seiReader; + private final boolean allowNonIdrKeyframes; + private final boolean detectAccessUnits; + private final NalUnitTargetBuffer sps; + private final NalUnitTargetBuffer pps; + private final NalUnitTargetBuffer sei; + private long totalBytesWritten; + private final boolean[] prefixFlags; + + private String formatId; + private TrackOutput output; + private SampleReader sampleReader; + + // State that should not be reset on seek. + private boolean hasOutputFormat; + + // Per PES packet state that gets reset at the start of each PES packet. + private long pesTimeUs; + + // State inherited from the TS packet header. + private boolean randomAccessIndicator; + + // Scratch variables to avoid allocations. + private final ParsableByteArray seiWrapper; + + /** + * @param seiReader An SEI reader for consuming closed caption channels. + * @param allowNonIdrKeyframes Whether to treat samples consisting of non-IDR I slices as + * synchronization samples (key-frames). + * @param detectAccessUnits Whether to split the input stream into access units (samples) based on + * slice headers. Pass {@code false} if the stream contains access unit delimiters (AUDs). + */ + public H264Reader(SeiReader seiReader, boolean allowNonIdrKeyframes, boolean detectAccessUnits) { + this.seiReader = seiReader; + this.allowNonIdrKeyframes = allowNonIdrKeyframes; + this.detectAccessUnits = detectAccessUnits; + prefixFlags = new boolean[3]; + sps = new NalUnitTargetBuffer(NAL_UNIT_TYPE_SPS, 128); + pps = new NalUnitTargetBuffer(NAL_UNIT_TYPE_PPS, 128); + sei = new NalUnitTargetBuffer(NAL_UNIT_TYPE_SEI, 128); + seiWrapper = new ParsableByteArray(); + } + + @Override + public void seek() { + NalUnitUtil.clearPrefixFlags(prefixFlags); + sps.reset(); + pps.reset(); + sei.reset(); + sampleReader.reset(); + totalBytesWritten = 0; + randomAccessIndicator = false; + } + + @Override + public void createTracks(ExtractorOutput extractorOutput, TrackIdGenerator idGenerator) { + idGenerator.generateNewId(); + formatId = idGenerator.getFormatId(); + output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_VIDEO); + sampleReader = new SampleReader(output, allowNonIdrKeyframes, detectAccessUnits); + seiReader.createTracks(extractorOutput, idGenerator); + } + + @Override + public void packetStarted(long pesTimeUs, @TsPayloadReader.Flags int flags) { + this.pesTimeUs = pesTimeUs; + randomAccessIndicator |= (flags & FLAG_RANDOM_ACCESS_INDICATOR) != 0; + } + + @Override + public void consume(ParsableByteArray data) { + int offset = data.getPosition(); + int limit = data.limit(); + byte[] dataArray = data.data; + + // Append the data to the buffer. + totalBytesWritten += data.bytesLeft(); + output.sampleData(data, data.bytesLeft()); + + // Scan the appended data, processing NAL units as they are encountered + while (true) { + int nalUnitOffset = NalUnitUtil.findNalUnit(dataArray, offset, limit, prefixFlags); + + if (nalUnitOffset == limit) { + // We've scanned to the end of the data without finding the start of another NAL unit. + nalUnitData(dataArray, offset, limit); + return; + } + + // We've seen the start of a NAL unit of the following type. + int nalUnitType = NalUnitUtil.getNalUnitType(dataArray, nalUnitOffset); + + // This is the number of bytes from the current offset to the start of the next NAL unit. + // It may be negative if the NAL unit started in the previously consumed data. + int lengthToNalUnit = nalUnitOffset - offset; + if (lengthToNalUnit > 0) { + nalUnitData(dataArray, offset, nalUnitOffset); + } + int bytesWrittenPastPosition = limit - nalUnitOffset; + long absolutePosition = totalBytesWritten - bytesWrittenPastPosition; + // Indicate the end of the previous NAL unit. If the length to the start of the next unit + // is negative then we wrote too many bytes to the NAL buffers. Discard the excess bytes + // when notifying that the unit has ended. + endNalUnit(absolutePosition, bytesWrittenPastPosition, + lengthToNalUnit < 0 ? -lengthToNalUnit : 0, pesTimeUs); + // Indicate the start of the next NAL unit. + startNalUnit(absolutePosition, nalUnitType, pesTimeUs); + // Continue scanning the data. + offset = nalUnitOffset + 3; + } + } + + @Override + public void packetFinished() { + // Do nothing. + } + + private void startNalUnit(long position, int nalUnitType, long pesTimeUs) { + if (!hasOutputFormat || sampleReader.needsSpsPps()) { + sps.startNalUnit(nalUnitType); + pps.startNalUnit(nalUnitType); + } + sei.startNalUnit(nalUnitType); + sampleReader.startNalUnit(position, nalUnitType, pesTimeUs); + } + + private void nalUnitData(byte[] dataArray, int offset, int limit) { + if (!hasOutputFormat || sampleReader.needsSpsPps()) { + sps.appendToNalUnit(dataArray, offset, limit); + pps.appendToNalUnit(dataArray, offset, limit); + } + sei.appendToNalUnit(dataArray, offset, limit); + sampleReader.appendToNalUnit(dataArray, offset, limit); + } + + private void endNalUnit(long position, int offset, int discardPadding, long pesTimeUs) { + if (!hasOutputFormat || sampleReader.needsSpsPps()) { + sps.endNalUnit(discardPadding); + pps.endNalUnit(discardPadding); + if (!hasOutputFormat) { + if (sps.isCompleted() && pps.isCompleted()) { + List<byte[]> initializationData = new ArrayList<>(); + initializationData.add(Arrays.copyOf(sps.nalData, sps.nalLength)); + initializationData.add(Arrays.copyOf(pps.nalData, pps.nalLength)); + NalUnitUtil.SpsData spsData = NalUnitUtil.parseSpsNalUnit(sps.nalData, 3, sps.nalLength); + NalUnitUtil.PpsData ppsData = NalUnitUtil.parsePpsNalUnit(pps.nalData, 3, pps.nalLength); + output.format( + Format.createVideoSampleFormat( + formatId, + MimeTypes.VIDEO_H264, + CodecSpecificDataUtil.buildAvcCodecString( + spsData.profileIdc, + spsData.constraintsFlagsAndReservedZero2Bits, + spsData.levelIdc), + /* bitrate= */ Format.NO_VALUE, + /* maxInputSize= */ Format.NO_VALUE, + spsData.width, + spsData.height, + /* frameRate= */ Format.NO_VALUE, + initializationData, + /* rotationDegrees= */ Format.NO_VALUE, + spsData.pixelWidthAspectRatio, + /* drmInitData= */ null)); + hasOutputFormat = true; + sampleReader.putSps(spsData); + sampleReader.putPps(ppsData); + sps.reset(); + pps.reset(); + } + } else if (sps.isCompleted()) { + NalUnitUtil.SpsData spsData = NalUnitUtil.parseSpsNalUnit(sps.nalData, 3, sps.nalLength); + sampleReader.putSps(spsData); + sps.reset(); + } else if (pps.isCompleted()) { + NalUnitUtil.PpsData ppsData = NalUnitUtil.parsePpsNalUnit(pps.nalData, 3, pps.nalLength); + sampleReader.putPps(ppsData); + pps.reset(); + } + } + if (sei.endNalUnit(discardPadding)) { + int unescapedLength = NalUnitUtil.unescapeStream(sei.nalData, sei.nalLength); + seiWrapper.reset(sei.nalData, unescapedLength); + seiWrapper.setPosition(4); // NAL prefix and nal_unit() header. + seiReader.consume(pesTimeUs, seiWrapper); + } + boolean sampleIsKeyFrame = + sampleReader.endNalUnit(position, offset, hasOutputFormat, randomAccessIndicator); + if (sampleIsKeyFrame) { + // This is either an IDR frame or the first I-frame since the random access indicator, so mark + // it as a keyframe. Clear the flag so that subsequent non-IDR I-frames are not marked as + // keyframes until we see another random access indicator. + randomAccessIndicator = false; + } + } + + /** Consumes a stream of NAL units and outputs samples. */ + private static final class SampleReader { + + private static final int DEFAULT_BUFFER_SIZE = 128; + + private static final int NAL_UNIT_TYPE_NON_IDR = 1; // Coded slice of a non-IDR picture + private static final int NAL_UNIT_TYPE_PARTITION_A = 2; // Coded slice data partition A + private static final int NAL_UNIT_TYPE_IDR = 5; // Coded slice of an IDR picture + private static final int NAL_UNIT_TYPE_AUD = 9; // Access unit delimiter + + private final TrackOutput output; + private final boolean allowNonIdrKeyframes; + private final boolean detectAccessUnits; + private final SparseArray<NalUnitUtil.SpsData> sps; + private final SparseArray<NalUnitUtil.PpsData> pps; + private final ParsableNalUnitBitArray bitArray; + + private byte[] buffer; + private int bufferLength; + + // Per NAL unit state. A sample consists of one or more NAL units. + private int nalUnitType; + private long nalUnitStartPosition; + private boolean isFilling; + private long nalUnitTimeUs; + private SliceHeaderData previousSliceHeader; + private SliceHeaderData sliceHeader; + + // Per sample state that gets reset at the start of each sample. + private boolean readingSample; + private long samplePosition; + private long sampleTimeUs; + private boolean sampleIsKeyframe; + + public SampleReader(TrackOutput output, boolean allowNonIdrKeyframes, + boolean detectAccessUnits) { + this.output = output; + this.allowNonIdrKeyframes = allowNonIdrKeyframes; + this.detectAccessUnits = detectAccessUnits; + sps = new SparseArray<>(); + pps = new SparseArray<>(); + previousSliceHeader = new SliceHeaderData(); + sliceHeader = new SliceHeaderData(); + buffer = new byte[DEFAULT_BUFFER_SIZE]; + bitArray = new ParsableNalUnitBitArray(buffer, 0, 0); + reset(); + } + + public boolean needsSpsPps() { + return detectAccessUnits; + } + + public void putSps(NalUnitUtil.SpsData spsData) { + sps.append(spsData.seqParameterSetId, spsData); + } + + public void putPps(NalUnitUtil.PpsData ppsData) { + pps.append(ppsData.picParameterSetId, ppsData); + } + + public void reset() { + isFilling = false; + readingSample = false; + sliceHeader.clear(); + } + + public void startNalUnit(long position, int type, long pesTimeUs) { + nalUnitType = type; + nalUnitTimeUs = pesTimeUs; + nalUnitStartPosition = position; + if ((allowNonIdrKeyframes && nalUnitType == NAL_UNIT_TYPE_NON_IDR) + || (detectAccessUnits && (nalUnitType == NAL_UNIT_TYPE_IDR + || nalUnitType == NAL_UNIT_TYPE_NON_IDR + || nalUnitType == NAL_UNIT_TYPE_PARTITION_A))) { + // Store the previous header and prepare to populate the new one. + SliceHeaderData newSliceHeader = previousSliceHeader; + previousSliceHeader = sliceHeader; + sliceHeader = newSliceHeader; + sliceHeader.clear(); + bufferLength = 0; + isFilling = true; + } + } + + /** + * Called to pass stream data. The data passed should not include the 3 byte start code. + * + * @param data Holds the data being passed. + * @param offset The offset of the data in {@code data}. + * @param limit The limit (exclusive) of the data in {@code data}. + */ + public void appendToNalUnit(byte[] data, int offset, int limit) { + if (!isFilling) { + return; + } + int readLength = limit - offset; + if (buffer.length < bufferLength + readLength) { + buffer = Arrays.copyOf(buffer, (bufferLength + readLength) * 2); + } + System.arraycopy(data, offset, buffer, bufferLength, readLength); + bufferLength += readLength; + + bitArray.reset(buffer, 0, bufferLength); + if (!bitArray.canReadBits(8)) { + return; + } + bitArray.skipBit(); // forbidden_zero_bit + int nalRefIdc = bitArray.readBits(2); + bitArray.skipBits(5); // nal_unit_type + + // Read the slice header using the syntax defined in ITU-T Recommendation H.264 (2013) + // subsection 7.3.3. + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + bitArray.readUnsignedExpGolombCodedInt(); // first_mb_in_slice + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + int sliceType = bitArray.readUnsignedExpGolombCodedInt(); + if (!detectAccessUnits) { + // There are AUDs in the stream so the rest of the header can be ignored. + isFilling = false; + sliceHeader.setSliceType(sliceType); + return; + } + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + int picParameterSetId = bitArray.readUnsignedExpGolombCodedInt(); + if (pps.indexOfKey(picParameterSetId) < 0) { + // We have not seen the PPS yet, so don't try to decode the slice header. + isFilling = false; + return; + } + NalUnitUtil.PpsData ppsData = pps.get(picParameterSetId); + NalUnitUtil.SpsData spsData = sps.get(ppsData.seqParameterSetId); + if (spsData.separateColorPlaneFlag) { + if (!bitArray.canReadBits(2)) { + return; + } + bitArray.skipBits(2); // colour_plane_id + } + if (!bitArray.canReadBits(spsData.frameNumLength)) { + return; + } + boolean fieldPicFlag = false; + boolean bottomFieldFlagPresent = false; + boolean bottomFieldFlag = false; + int frameNum = bitArray.readBits(spsData.frameNumLength); + if (!spsData.frameMbsOnlyFlag) { + if (!bitArray.canReadBits(1)) { + return; + } + fieldPicFlag = bitArray.readBit(); + if (fieldPicFlag) { + if (!bitArray.canReadBits(1)) { + return; + } + bottomFieldFlag = bitArray.readBit(); + bottomFieldFlagPresent = true; + } + } + boolean idrPicFlag = nalUnitType == NAL_UNIT_TYPE_IDR; + int idrPicId = 0; + if (idrPicFlag) { + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + idrPicId = bitArray.readUnsignedExpGolombCodedInt(); + } + int picOrderCntLsb = 0; + int deltaPicOrderCntBottom = 0; + int deltaPicOrderCnt0 = 0; + int deltaPicOrderCnt1 = 0; + if (spsData.picOrderCountType == 0) { + if (!bitArray.canReadBits(spsData.picOrderCntLsbLength)) { + return; + } + picOrderCntLsb = bitArray.readBits(spsData.picOrderCntLsbLength); + if (ppsData.bottomFieldPicOrderInFramePresentFlag && !fieldPicFlag) { + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + deltaPicOrderCntBottom = bitArray.readSignedExpGolombCodedInt(); + } + } else if (spsData.picOrderCountType == 1 + && !spsData.deltaPicOrderAlwaysZeroFlag) { + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + deltaPicOrderCnt0 = bitArray.readSignedExpGolombCodedInt(); + if (ppsData.bottomFieldPicOrderInFramePresentFlag && !fieldPicFlag) { + if (!bitArray.canReadExpGolombCodedNum()) { + return; + } + deltaPicOrderCnt1 = bitArray.readSignedExpGolombCodedInt(); + } + } + sliceHeader.setAll(spsData, nalRefIdc, sliceType, frameNum, picParameterSetId, fieldPicFlag, + bottomFieldFlagPresent, bottomFieldFlag, idrPicFlag, idrPicId, picOrderCntLsb, + deltaPicOrderCntBottom, deltaPicOrderCnt0, deltaPicOrderCnt1); + isFilling = false; + } + + public boolean endNalUnit( + long position, int offset, boolean hasOutputFormat, boolean randomAccessIndicator) { + if (nalUnitType == NAL_UNIT_TYPE_AUD + || (detectAccessUnits && sliceHeader.isFirstVclNalUnitOfPicture(previousSliceHeader))) { + // If the NAL unit ending is the start of a new sample, output the previous one. + if (hasOutputFormat && readingSample) { + int nalUnitLength = (int) (position - nalUnitStartPosition); + outputSample(offset + nalUnitLength); + } + samplePosition = nalUnitStartPosition; + sampleTimeUs = nalUnitTimeUs; + sampleIsKeyframe = false; + readingSample = true; + } + boolean treatIFrameAsKeyframe = + allowNonIdrKeyframes ? sliceHeader.isISlice() : randomAccessIndicator; + sampleIsKeyframe |= + nalUnitType == NAL_UNIT_TYPE_IDR + || (treatIFrameAsKeyframe && nalUnitType == NAL_UNIT_TYPE_NON_IDR); + return sampleIsKeyframe; + } + + private void outputSample(int offset) { + @C.BufferFlags int flags = sampleIsKeyframe ? C.BUFFER_FLAG_KEY_FRAME : 0; + int size = (int) (nalUnitStartPosition - samplePosition); + output.sampleMetadata(sampleTimeUs, flags, size, offset, null); + } + + private static final class SliceHeaderData { + + private static final int SLICE_TYPE_I = 2; + private static final int SLICE_TYPE_ALL_I = 7; + + private boolean isComplete; + private boolean hasSliceType; + + private SpsData spsData; + private int nalRefIdc; + private int sliceType; + private int frameNum; + private int picParameterSetId; + private boolean fieldPicFlag; + private boolean bottomFieldFlagPresent; + private boolean bottomFieldFlag; + private boolean idrPicFlag; + private int idrPicId; + private int picOrderCntLsb; + private int deltaPicOrderCntBottom; + private int deltaPicOrderCnt0; + private int deltaPicOrderCnt1; + + public void clear() { + hasSliceType = false; + isComplete = false; + } + + public void setSliceType(int sliceType) { + this.sliceType = sliceType; + hasSliceType = true; + } + + public void setAll( + SpsData spsData, + int nalRefIdc, + int sliceType, + int frameNum, + int picParameterSetId, + boolean fieldPicFlag, + boolean bottomFieldFlagPresent, + boolean bottomFieldFlag, + boolean idrPicFlag, + int idrPicId, + int picOrderCntLsb, + int deltaPicOrderCntBottom, + int deltaPicOrderCnt0, + int deltaPicOrderCnt1) { + this.spsData = spsData; + this.nalRefIdc = nalRefIdc; + this.sliceType = sliceType; + this.frameNum = frameNum; + this.picParameterSetId = picParameterSetId; + this.fieldPicFlag = fieldPicFlag; + this.bottomFieldFlagPresent = bottomFieldFlagPresent; + this.bottomFieldFlag = bottomFieldFlag; + this.idrPicFlag = idrPicFlag; + this.idrPicId = idrPicId; + this.picOrderCntLsb = picOrderCntLsb; + this.deltaPicOrderCntBottom = deltaPicOrderCntBottom; + this.deltaPicOrderCnt0 = deltaPicOrderCnt0; + this.deltaPicOrderCnt1 = deltaPicOrderCnt1; + isComplete = true; + hasSliceType = true; + } + + public boolean isISlice() { + return hasSliceType && (sliceType == SLICE_TYPE_ALL_I || sliceType == SLICE_TYPE_I); + } + + private boolean isFirstVclNalUnitOfPicture(SliceHeaderData other) { + // See ISO 14496-10 subsection 7.4.1.2.4. + return isComplete + && (!other.isComplete + || frameNum != other.frameNum + || picParameterSetId != other.picParameterSetId + || fieldPicFlag != other.fieldPicFlag + || (bottomFieldFlagPresent + && other.bottomFieldFlagPresent + && bottomFieldFlag != other.bottomFieldFlag) + || (nalRefIdc != other.nalRefIdc && (nalRefIdc == 0 || other.nalRefIdc == 0)) + || (spsData.picOrderCountType == 0 + && other.spsData.picOrderCountType == 0 + && (picOrderCntLsb != other.picOrderCntLsb + || deltaPicOrderCntBottom != other.deltaPicOrderCntBottom)) + || (spsData.picOrderCountType == 1 + && other.spsData.picOrderCountType == 1 + && (deltaPicOrderCnt0 != other.deltaPicOrderCnt0 + || deltaPicOrderCnt1 != other.deltaPicOrderCnt1)) + || idrPicFlag != other.idrPicFlag + || (idrPicFlag && other.idrPicFlag && idrPicId != other.idrPicId)); + } + } + } +} |