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further improvements

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This commit is contained in:
Rohit Singh 2024-01-23 12:41:16 +01:00
parent 6ac888ec3b
commit 71673d65f3
2 changed files with 208 additions and 148 deletions
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42
libraries/extractor/src/main/java/androidx/media3/extractor/MpeghUtil.java
View file

@ -52,8 +52,9 @@ public final class MpeghUtil {
/**
* Parses an MHAS packet header. See ISO_IEC_23008-3;2022, 14.2.1, Table 222.
* The reading position of {@code data} will be modified.
*
* @param data The bit array to parse.
* @param data The data to parse, positioned at the start of the MHAS packet header.
* @return The {@link MhasPacketHeader} info.
* @throws ParserException if a valid {@link MhasPacketHeader} cannot be parsed.
*/
@ -93,8 +94,10 @@ public final class MpeghUtil {
/**
* Obtains the sampling rate of the current MPEG-H frame. See ISO_IEC_23003-3;2020, 5.2, Table 7.
* The reading position of {@code data} will be modified.
*
* @param data The bit array holding the bits to be parsed.
* @param data The data to parse, positioned at the start of the fields to obtain the sampling
* rate from.
* @return The sampling frequency.
* @throws ParserException if sampling frequency could not be obtained.
*/
@ -249,8 +252,9 @@ public final class MpeghUtil {
/**
* Obtains an escaped value from an MPEG-H bit stream. See ISO_IEC_23003-3;2020, 5.2, Table 19.
* The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the escaped value.
* @param bits1 number of bits to be parsed.
* @param bits2 number of bits to be parsed.
* @param bits3 number of bits to be parsed.
@ -274,8 +278,10 @@ public final class MpeghUtil {
/**
* Obtains the necessary info of the Mpegh3daConfig from an MPEG-H bit stream. See
* ISO_IEC_23008-3;2022, 5.2.2.1, Table 15.
* The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the payload of an Mpegh3daConfig
* packet.
* @return The {@link Mpegh3daConfig}.
* @throws ParserException if a valid {@link Mpegh3daConfig} cannot be parsed.
*/
@ -332,8 +338,10 @@ public final class MpeghUtil {
/**
* Obtains the number of truncated samples of the AudioTruncationInfo from an MPEG-H bit stream.
* See ISO_IEC_23008-3;2022, 14.2.2, Table 225.
* The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the payload of an AudioTruncation
* packet.
* @return The number of truncated samples.
*/
public static int parseAudioTruncationInfo(ParsableBitArray data) {
@ -346,9 +354,9 @@ public final class MpeghUtil {
/**
* Skips the SpeakerConfig3d from an MPEG-H bit stream. See ISO_IEC_23008-3;2022, 5.2.2.2, Table
* 18.
* 18. The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the SpeakerConfig3d field.
*/
private static void skipSpeakerConfig3d(ParsableBitArray data) {
int speakerLayoutType = data.readBits(2);
@ -367,7 +375,10 @@ public final class MpeghUtil {
/**
* Skips the mpegh3daFlexibleSpeakerConfig from an MPEG-H bit stream. See ISO_IEC_23008-3;2022,
* 5.2.2.2, Table 19.
* 5.2.2.2, Table 19. The reading position of {@code data} will be modified.
*
* @param data The data to parse, positioned at the start of the Mpegh3daFlexibleSpeakerConfig
* field.
*/
private static void skipMpegh3daFlexibleSpeakerConfig(
ParsableBitArray data, int numberOfSpeakers) {
@ -408,9 +419,9 @@ public final class MpeghUtil {
/**
* Obtains the necessary info of Signals3d from an MPEG-H bit stream. See ISO_IEC_23008-3;2022,
* 5.2.2.1, Table 17.
* 5.2.2.1, Table 17. The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the Signals3d field.
* @return The number of overall signals in the bit stream.
*/
private static int parseSignals3d(ParsableBitArray data) {
@ -434,9 +445,9 @@ public final class MpeghUtil {
/**
* Skips the Mpegh3daDecoderConfig from an MPEG-H bit stream. See ISO_IEC_23008-3;2022, 5.2.2.3,
* Table 21.
* Table 21. The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the Mpegh3daDecoderConfig field.
* @param numSignals The number of overall signals.
* @param sbrRatioIndex The SBR ration index.
*/
@ -517,9 +528,9 @@ public final class MpeghUtil {
/**
* Obtains the necessary info of the Mpegh3daCoreConfig from an MPEG-H bit stream. See
* ISO_IEC_23008-3;2022, 5.2.2.3, Table 24.
* ISO_IEC_23008-3;2022, 5.2.2.3, Table 24. The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the Mpegh3daCoreConfig field.
* @return The enhanced noise filling flag.
*/
private static boolean parseMpegh3daCoreConfig(ParsableBitArray data) {
@ -535,8 +546,9 @@ public final class MpeghUtil {
/**
* Skips the SbrConfig from an MPEG-H bit stream. See ISO_IEC_23003-3;2020, 5.2, Table 14.
* The reading position of {@code data} will be modified.
*
* @param data The bit array to be parsed.
* @param data The data to parse, positioned at the start of the SbrConfig field.
*/
private static void skipSbrConfig(ParsableBitArray data) {
data.skipBits(3); // harmonicSBR(1), bs_interTes(1), bs_pvc(1)

314
libraries/extractor/src/main/java/androidx/media3/extractor/ts/MpeghReader.java
View file

@ -132,6 +132,8 @@ public final class MpeghReader implements ElementaryStreamReader {
public void packetStarted(long pesTimeUs, @TsPayloadReader.Flags int flags) {
this.flags = flags;
// check if data is pending (an MPEG-H frame could not be completed or parsing the header
// could not be finished)
if (!rapPending && (frameBytes != 0 || !headerDataFinished)) {
dataPending = true;
}
@ -149,8 +151,6 @@ public final class MpeghReader implements ElementaryStreamReader {
public void consume(ParsableByteArray data) throws ParserException {
Assertions.checkStateNotNull(output); // Asserts that createTracks has been called.
int headerDataPos;
ParsableBitArray bitArray = new ParsableBitArray();
while (data.bytesLeft() > 0) {
switch (state) {
case STATE_FINDING_SYNC:
@ -159,133 +159,29 @@ public final class MpeghReader implements ElementaryStreamReader {
}
break;
case STATE_READING_PACKET_HEADER:
// check if the gathering of data in header scratch buffer was finished and adjust
// remaining bytes
if (headerDataFinished && headerScratchBytes.getPosition() > 0) {
System.arraycopy(
headerScratchBytes.getData(),
headerScratchBytes.getPosition(),
headerScratchBytes.getData(),
0,
headerScratchBytes.bytesLeft());
headerScratchBytes.setPosition(headerScratchBytes.bytesLeft());
headerDataFinished = false;
}
maybeAdjustHeaderScratchBuffer();
// read into header scratch buffer
if (continueRead(data, headerScratchBytes, MpeghUtil.MAX_MHAS_PACKET_HEADER_SIZE)) {
// make the scratch bytes available for parsing
headerScratchBytes.setPosition(0);
bitArray.reset(headerScratchBytes);
// parse the MHAS packet header
header = MpeghUtil.parseMhasPacketHeader(bitArray);
parseHeader();
// write the packet header to output
output.sampleData(headerScratchBytes, header.headerLength);
payloadBytesRead = 0;
frameBytes += header.packetLength + header.headerLength;
if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_AUDIOTRUNCATION
|| header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DACFG) {
dataScratchBytes.ensureCapacity(header.packetLength);
dataScratchBytes.setPosition(0);
dataScratchBytes.setLimit(header.packetLength);
}
// MHAS packet header finished -> obtain the packet payload
state = STATE_READING_PACKET_PAYLOAD;
headerDataFinished = true;
}
break;
case STATE_READING_PACKET_PAYLOAD:
if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DACFG
|| header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_AUDIOTRUNCATION) {
// read bytes from header scratch buffer into the data scratch buffer
headerDataPos = headerScratchBytes.getPosition();
if (headerDataPos != MpeghUtil.MAX_MHAS_PACKET_HEADER_SIZE) {
continueRead(headerScratchBytes, dataScratchBytes, header.packetLength);
}
headerScratchBytes.setPosition(headerDataPos);
// read bytes from input data into the data scratch buffer
int dataStartPos = data.getPosition();
continueRead(data, dataScratchBytes, header.packetLength);
data.setPosition(dataStartPos);
}
int bytesToRead;
// read bytes from header scratch buffer and write them into the output
headerDataPos = headerScratchBytes.getPosition();
if (headerDataPos != MpeghUtil.MAX_MHAS_PACKET_HEADER_SIZE) {
bytesToRead =
min(headerScratchBytes.bytesLeft(), header.packetLength - payloadBytesRead);
output.sampleData(headerScratchBytes, bytesToRead);
payloadBytesRead += bytesToRead;
}
// read bytes from input data and write them into the output
bytesToRead = min(data.bytesLeft(), header.packetLength - payloadBytesRead);
output.sampleData(data, bytesToRead);
payloadBytesRead += bytesToRead;
maybeCopyToDataScratchBuffer(data);
writeSampleData(data);
if (payloadBytesRead == header.packetLength) {
dataScratchBytes.setPosition(0);
bitArray.reset(dataScratchBytes);
ParsableBitArray bitArray = new ParsableBitArray(dataScratchBytes.getData());
if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DACFG) {
MpeghUtil.Mpegh3daConfig config = MpeghUtil.parseMpegh3daConfig(bitArray);
samplingRate = config.samplingFrequency;
standardFrameLength = config.standardFrameSamples;
if (mainStreamLabel != header.packetLabel) {
mainStreamLabel = header.packetLabel;
// set the output format
String codecs = "mhm1";
if (config.profileLevelIndication != C.INDEX_UNSET) {
codecs += String.format(".%02X", config.profileLevelIndication);
}
@Nullable List<byte[]> initializationData = null;
if (config.compatibleProfileLevelSet != null
&& config.compatibleProfileLevelSet.length > 0) {
// The first entry in initializationData is reserved for the audio specific
// config.
initializationData =
ImmutableList.of(Util.EMPTY_BYTE_ARRAY, config.compatibleProfileLevelSet);
}
Format format =
new Format.Builder()
.setId(formatId)
.setSampleMimeType(MimeTypes.AUDIO_MPEGH_MHM1)
.setSampleRate(samplingRate)
.setCodecs(codecs)
.setInitializationData(initializationData)
.build();
output.format(format);
}
configFound = true;
parseConfig(bitArray);
} else if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_AUDIOTRUNCATION) {
truncationSamples = MpeghUtil.parseAudioTruncationInfo(bitArray);
} else if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DAFRAME) {
@C.BufferFlags int flag = 0;
// if we have a frame with an mpegh3daConfig, set the first obtained AU to a key frame
if (configFound) {
flag = C.BUFFER_FLAG_KEY_FRAME;
rapPending = false;
}
double sampleDurationUs =
(double) C.MICROS_PER_SECOND
* (standardFrameLength - truncationSamples)
/ samplingRate;
long pts = Math.round(timeUs);
if (dataPending) {
dataPending = false;
timeUs = timeUsPending;
} else {
timeUs += sampleDurationUs;
}
output.sampleMetadata(pts, flag, frameBytes, 0, null);
configFound = false;
truncationSamples = 0;
frameBytes = 0;
finalizeFrame();
}
header = null;
// MHAS packet payload finished -> obtain a new packet header
state = STATE_READING_PACKET_HEADER;
}
@ -317,6 +213,23 @@ public final class MpeghReader implements ElementaryStreamReader {
return target.getPosition() == targetLength;
}
/**
* Copies data from the provided {@code source} into a given {@code target} without progressing
* the position of the {@code source}.
*
* @param source The source from which to read.
* @param target The target into which data is to be read.
* @param targetLength The target length of the read.
*/
private void copyData(
ParsableByteArray source, ParsableByteArray target, int targetLength) {
int sourcePosition = source.getPosition();
int bytesToRead = min(source.bytesLeft(), targetLength - target.getPosition());
source.readBytes(target.getData(), target.getPosition(), bytesToRead);
target.setPosition(target.getPosition() + bytesToRead);
source.setPosition(sourcePosition);
}
/**
* Locates the next SYNC value in the buffer, advancing the position to the byte that immediately
* follows it. If SYNC was not located, the position is advanced to the limit.
@ -325,31 +238,166 @@ public final class MpeghReader implements ElementaryStreamReader {
* @return Whether SYNC was found.
*/
private boolean skipToNextSync(ParsableByteArray pesBuffer) {
// we are still waiting for a RAP frame
if (rapPending) {
if ((flags & FLAG_RANDOM_ACCESS_INDICATOR) == 0) {
// RAI is not signalled -> drop the PES data
pesBuffer.setPosition(pesBuffer.limit());
return false;
}
if ((flags & FLAG_RANDOM_ACCESS_INDICATOR) == 0) {
// RAI is not signalled -> drop the PES data
pesBuffer.setPosition(pesBuffer.limit());
return false;
}
if ((flags & FLAG_DATA_ALIGNMENT_INDICATOR) == 0) {
// if RAI is signalled but the data is not aligned we need to find the sync packet
while (pesBuffer.bytesLeft() > 0) {
syncBytes <<= C.BITS_PER_BYTE;
syncBytes |= pesBuffer.readUnsignedByte();
if (MpeghUtil.isSyncWord(syncBytes)) {
pesBuffer.setPosition(pesBuffer.getPosition() - MpeghUtil.MHAS_SYNC_WORD_LENGTH);
syncBytes = 0;
return true;
}
if ((flags & FLAG_DATA_ALIGNMENT_INDICATOR) == 0) {
// if RAI is signalled but the data is not aligned we need to find the sync packet
while (pesBuffer.bytesLeft() > 0) {
syncBytes <<= C.BITS_PER_BYTE;
syncBytes |= pesBuffer.readUnsignedByte();
if (MpeghUtil.isSyncWord(syncBytes)) {
pesBuffer.setPosition(pesBuffer.getPosition() - MpeghUtil.MHAS_SYNC_WORD_LENGTH);
syncBytes = 0;
return true;
}
} else {
return true;
}
} else {
pesBuffer.setPosition(pesBuffer.limit());
return true;
}
return false;
}
/** Parses the MHAS packet header.
*
* @throws ParserException if a valid {@link MpeghUtil.Mpegh3daConfig} cannot be parsed.
*/
private void parseHeader() throws ParserException {
headerScratchBytes.setPosition(0);
ParsableBitArray bitArray = new ParsableBitArray(headerScratchBytes.getData());
// parse the MHAS packet header
header = MpeghUtil.parseMhasPacketHeader(bitArray);
payloadBytesRead = 0;
frameBytes += header.packetLength + header.headerLength;
if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_AUDIOTRUNCATION
|| header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DACFG) {
// prepare data scratch buffer
dataScratchBytes.ensureCapacity(header.packetLength);
dataScratchBytes.setPosition(0);
dataScratchBytes.setLimit(header.packetLength);
}
headerDataFinished = true;
}
/** Adjust the header scratch buffer. */
private void maybeAdjustHeaderScratchBuffer() {
// check if the gathering of data in header scratch buffer was finished and move
// remaining bytes to the start of the buffer.
if (headerDataFinished && headerScratchBytes.getPosition() > 0) {
System.arraycopy(
headerScratchBytes.getData(),
headerScratchBytes.getPosition(),
headerScratchBytes.getData(),
0,
headerScratchBytes.bytesLeft());
headerScratchBytes.setPosition(headerScratchBytes.bytesLeft());
headerDataFinished = false;
}
}
/**
* Copies data to the data scratch buffer.
*
* @param data A {@link ParsableByteArray} from which to read the sample data. Its position
* will not be changed.
*/
private void maybeCopyToDataScratchBuffer(ParsableByteArray data) {
if (header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_MPEGH3DACFG
|| header.packetType == MpeghUtil.MhasPacketHeader.PACTYP_AUDIOTRUNCATION) {
// read bytes from header scratch buffer into the data scratch buffer
if (headerScratchBytes.getPosition() != MpeghUtil.MAX_MHAS_PACKET_HEADER_SIZE) {
copyData(headerScratchBytes, dataScratchBytes, header.packetLength);
}
// read bytes from input data into the data scratch buffer
copyData(data, dataScratchBytes, header.packetLength);
}
}
/**
* Writes sample data to the output.
*
* @param data A {@link ParsableByteArray} from which to read the sample data.
*/
private void writeSampleData(ParsableByteArray data) {
int bytesToRead;
// read bytes from header scratch buffer and write them into the output
if (headerScratchBytes.getPosition() != MpeghUtil.MAX_MHAS_PACKET_HEADER_SIZE) {
bytesToRead =
min(headerScratchBytes.bytesLeft(), header.packetLength - payloadBytesRead);
output.sampleData(headerScratchBytes, bytesToRead);
payloadBytesRead += bytesToRead;
}
// read bytes from input data and write them into the output
bytesToRead = min(data.bytesLeft(), header.packetLength - payloadBytesRead);
output.sampleData(data, bytesToRead);
payloadBytesRead += bytesToRead;
}
/**
* Parses the config and sets the output format.
*
* @param bitArray The data to parse, positioned at the start of the
* {@link MpeghUtil.Mpegh3daConfig} field.
* @throws ParserException if a valid {@link MpeghUtil.Mpegh3daConfig} cannot be parsed.
*/
private void parseConfig(ParsableBitArray bitArray) throws ParserException {
MpeghUtil.Mpegh3daConfig config = MpeghUtil.parseMpegh3daConfig(bitArray);
samplingRate = config.samplingFrequency;
standardFrameLength = config.standardFrameSamples;
if (mainStreamLabel != header.packetLabel) {
mainStreamLabel = header.packetLabel;
// set the output format
String codecs = "mhm1";
if (config.profileLevelIndication != C.INDEX_UNSET) {
codecs += String.format(".%02X", config.profileLevelIndication);
}
@Nullable List<byte[]> initializationData = null;
if (config.compatibleProfileLevelSet != null
&& config.compatibleProfileLevelSet.length > 0) {
// The first entry in initializationData is reserved for the audio specific
// config.
initializationData =
ImmutableList.of(Util.EMPTY_BYTE_ARRAY, config.compatibleProfileLevelSet);
}
Format format =
new Format.Builder()
.setId(formatId)
.setSampleMimeType(MimeTypes.AUDIO_MPEGH_MHM1)
.setSampleRate(samplingRate)
.setCodecs(codecs)
.setInitializationData(initializationData)
.build();
output.format(format);
}
configFound = true;
}
/** Finalizes an MPEG-H frame. */
private void finalizeFrame() {
@C.BufferFlags int flag = 0;
// if we have a frame with an mpegh3daConfig, set the obtained AU to a key frame
if (configFound) {
flag = C.BUFFER_FLAG_KEY_FRAME;
rapPending = false;
}
double sampleDurationUs =
(double) C.MICROS_PER_SECOND * (standardFrameLength - truncationSamples) / samplingRate;
long pts = Math.round(timeUs);
if (dataPending) {
dataPending = false;
timeUs = timeUsPending;
} else {
timeUs += sampleDurationUs;
}
output.sampleMetadata(pts, flag, frameBytes, 0, null);
configFound = false;
truncationSamples = 0;
frameBytes = 0;
}
}