/**
* Reads an EBML variable-length integer (varint) from an {@link ExtractorInput} such that reading
* can be resumed later if an error occurs having read only some of it.
*
* <p>If an value is successfully read, then the reader will automatically reset itself ready to
* read another value.
*
* <p>If an {@link IOException} or {@link InterruptedException} is throw, the read can be resumed
* later by calling this method again, passing an {@link ExtractorInput} providing data starting
* where the previous one left off.
*
* @param input The {@link ExtractorInput} from which the integer should be read.
* @param allowEndOfInput True if encountering the end of the input having read no data is
* allowed, and should result in {@link C#RESULT_END_OF_INPUT} being returned. False if it
* should be considered an error, causing an {@link EOFException} to be thrown.
* @param removeLengthMask Removes the variable-length integer length mask from the value.
* @param maximumAllowedLength Maximum allowed length of the variable integer to be read.
* @return The read value, or {@link C#RESULT_END_OF_INPUT} if {@code allowEndOfStream} is true
* and the end of the input was encountered, or {@link C#RESULT_MAX_LENGTH_EXCEEDED} if the
* length of the varint exceeded maximumAllowedLength.
* @throws IOException If an error occurs reading from the input.
* @throws InterruptedException If the thread is interrupted.
*/
public long readUnsignedVarint(
ExtractorInput input,
boolean allowEndOfInput,
boolean removeLengthMask,
int maximumAllowedLength)
throws IOException, InterruptedException {
if (state == STATE_BEGIN_READING) {
// Read the first byte to establish the length.
if (!input.readFully(scratch, 0, 1, allowEndOfInput)) {
return C.RESULT_END_OF_INPUT;
}
int firstByte = scratch[0] & 0xFF;
length = parseUnsignedVarintLength(firstByte);
if (length == -1) {
throw new IllegalStateException("No valid varint length mask found");
}
state = STATE_READ_CONTENTS;
}
if (length > maximumAllowedLength) {
state = STATE_BEGIN_READING;
return C.RESULT_MAX_LENGTH_EXCEEDED;
}
if (length != 1) {
// Read the remaining bytes.
input.readFully(scratch, 1, length - 1);
}
state = STATE_BEGIN_READING;
return assembleVarint(scratch, length, removeLengthMask);
}
private void readAtomPayload(ExtractorInput input) throws IOException, InterruptedException {
int atomPayloadSize = (int) atomSize - atomHeaderBytesRead;
if (atomData != null) {
input.readFully(atomData.data, Atom.HEADER_SIZE, atomPayloadSize);
onLeafAtomRead(new LeafAtom(atomType, atomData), input.getPosition());
} else {
input.skipFully(atomPayloadSize);
}
long currentPosition = input.getPosition();
while (!containerAtoms.isEmpty() && containerAtoms.peek().endPosition == currentPosition) {
onContainerAtomRead(containerAtoms.pop());
}
enterReadingAtomHeaderState();
}
/**
* Attempts to extract the next sample in the current mdat atom.
*
* <p>If there are no more samples in the current mdat atom then the parser state is transitioned
* to {@link #STATE_READING_ATOM_HEADER} and {@code false} is returned.
*
* <p>It is possible for a sample to be extracted in part in the case that an exception is thrown.
* In this case the method can be called again to extract the remainder of the sample.
*
* @param input The {@link ExtractorInput} from which to read data.
* @return True if a sample was extracted. False otherwise.
* @throws IOException If an error occurs reading from the input.
* @throws InterruptedException If the thread is interrupted.
*/
private boolean readSample(ExtractorInput input) throws IOException, InterruptedException {
if (sampleIndex == 0) {
int bytesToSkip = (int) (fragmentRun.dataPosition - input.getPosition());
checkState(bytesToSkip >= 0, "Offset to sample data was negative.");
input.skipFully(bytesToSkip);
}
if (sampleIndex >= fragmentRun.length) {
int bytesToSkip = (int) (endOfMdatPosition - input.getPosition());
checkState(bytesToSkip >= 0, "Offset to end of mdat was negative.");
input.skipFully(bytesToSkip);
// We've run out of samples in the current mdat atom.
enterReadingAtomHeaderState();
return false;
}
if (parserState == STATE_READING_SAMPLE_START) {
sampleSize = fragmentRun.sampleSizeTable[sampleIndex];
if (fragmentRun.definesEncryptionData) {
sampleBytesWritten = appendSampleEncryptionData(fragmentRun.sampleEncryptionData);
sampleSize += sampleBytesWritten;
} else {
sampleBytesWritten = 0;
}
sampleCurrentNalBytesRemaining = 0;
parserState = STATE_READING_SAMPLE_CONTINUE;
}
if (track.nalUnitLengthFieldLength != -1) {
// Zero the top three bytes of the array that we'll use to parse nal unit lengths, in case
// they're only 1 or 2 bytes long.
byte[] nalLengthData = nalLength.data;
nalLengthData[0] = 0;
nalLengthData[1] = 0;
nalLengthData[2] = 0;
int nalUnitLengthFieldLength = track.nalUnitLengthFieldLength;
int nalUnitLengthFieldLengthDiff = 4 - track.nalUnitLengthFieldLength;
// NAL units are length delimited, but the decoder requires start code delimited units.
// Loop until we've written the sample to the track output, replacing length delimiters with
// start codes as we encounter them.
while (sampleBytesWritten < sampleSize) {
if (sampleCurrentNalBytesRemaining == 0) {
// Read the NAL length so that we know where we find the next one.
input.readFully(nalLength.data, nalUnitLengthFieldLengthDiff, nalUnitLengthFieldLength);
nalLength.setPosition(0);
sampleCurrentNalBytesRemaining = nalLength.readUnsignedIntToInt();
// Write a start code for the current NAL unit.
nalStartCode.setPosition(0);
trackOutput.sampleData(nalStartCode, 4);
sampleBytesWritten += 4;
sampleSize += nalUnitLengthFieldLengthDiff;
} else {
// Write the payload of the NAL unit.
int writtenBytes = trackOutput.sampleData(input, sampleCurrentNalBytesRemaining, false);
sampleBytesWritten += writtenBytes;
sampleCurrentNalBytesRemaining -= writtenBytes;
}
}
} else {
while (sampleBytesWritten < sampleSize) {
int writtenBytes = trackOutput.sampleData(input, sampleSize - sampleBytesWritten, false);
sampleBytesWritten += writtenBytes;
}
}
long sampleTimeUs = fragmentRun.getSamplePresentationTime(sampleIndex) * 1000L;
int sampleFlags =
(fragmentRun.definesEncryptionData ? C.SAMPLE_FLAG_ENCRYPTED : 0)
| (fragmentRun.sampleIsSyncFrameTable[sampleIndex] ? C.SAMPLE_FLAG_SYNC : 0);
int sampleDescriptionIndex = fragmentRun.header.sampleDescriptionIndex;
byte[] encryptionKey =
fragmentRun.definesEncryptionData
? track.sampleDescriptionEncryptionBoxes[sampleDescriptionIndex].keyId
: null;
trackOutput.sampleMetadata(sampleTimeUs, sampleFlags, sampleSize, 0, encryptionKey);
sampleIndex++;
parserState = STATE_READING_SAMPLE_START;
return true;
}
private boolean readAtomHeader(ExtractorInput input) throws IOException, InterruptedException {
if (atomHeaderBytesRead == 0) {
// Read the standard length atom header.
if (!input.readFully(atomHeader.data, 0, Atom.HEADER_SIZE, true)) {
return false;
}
atomHeaderBytesRead = Atom.HEADER_SIZE;
atomHeader.setPosition(0);
atomSize = atomHeader.readUnsignedInt();
atomType = atomHeader.readInt();
}
if (atomSize == Atom.LONG_SIZE_PREFIX) {
// Read the extended atom size.
int headerBytesRemaining = Atom.LONG_HEADER_SIZE - Atom.HEADER_SIZE;
input.readFully(atomHeader.data, Atom.HEADER_SIZE, headerBytesRemaining);
atomHeaderBytesRead += headerBytesRemaining;
atomSize = atomHeader.readUnsignedLongToLong();
}
long atomPosition = input.getPosition() - atomHeaderBytesRead;
if (atomType == Atom.TYPE_moof) {
// The data positions may be updated when parsing the tfhd/trun.
fragmentRun.auxiliaryDataPosition = atomPosition;
fragmentRun.dataPosition = atomPosition;
}
if (atomType == Atom.TYPE_mdat) {
endOfMdatPosition = atomPosition + atomSize;
if (!haveOutputSeekMap) {
extractorOutput.seekMap(SeekMap.UNSEEKABLE);
haveOutputSeekMap = true;
}
if (fragmentRun.sampleEncryptionDataNeedsFill) {
parserState = STATE_READING_ENCRYPTION_DATA;
} else {
parserState = STATE_READING_SAMPLE_START;
}
return true;
}
if (shouldParseContainerAtom(atomType)) {
long endPosition = input.getPosition() + atomSize - Atom.HEADER_SIZE;
containerAtoms.add(new ContainerAtom(atomType, endPosition));
enterReadingAtomHeaderState();
} else if (shouldParseLeafAtom(atomType)) {
// We don't support parsing of leaf atoms that define extended atom sizes, or that have
// lengths greater than Integer.MAX_VALUE.
checkState(atomHeaderBytesRead == Atom.HEADER_SIZE);
checkState(atomSize <= Integer.MAX_VALUE);
atomData = new ParsableByteArray((int) atomSize);
System.arraycopy(atomHeader.data, 0, atomData.data, 0, Atom.HEADER_SIZE);
parserState = STATE_READING_ATOM_PAYLOAD;
} else {
// We don't support skipping of atoms that have lengths greater than Integer.MAX_VALUE.
checkState(atomSize <= Integer.MAX_VALUE);
atomData = null;
parserState = STATE_READING_ATOM_PAYLOAD;
}
return true;
}
