@Override
public int read(DataSource dataSource) throws IOException {
int bytesRead =
dataSource.read(tsPacketBuffer.data, tsPacketBytesRead, TS_PACKET_SIZE - tsPacketBytesRead);
if (bytesRead == -1) {
return -1;
}
tsPacketBytesRead += bytesRead;
if (tsPacketBytesRead < TS_PACKET_SIZE) {
// We haven't read the whole packet yet.
return bytesRead;
}
// Reset before reading the packet.
tsPacketBytesRead = 0;
tsPacketBuffer.setPosition(0);
tsPacketBuffer.setLimit(TS_PACKET_SIZE);
int syncByte = tsPacketBuffer.readUnsignedByte();
if (syncByte != TS_SYNC_BYTE) {
return bytesRead;
}
tsPacketBuffer.readBytes(tsScratch, 3);
tsScratch.skipBits(1); // transport_error_indicator
boolean payloadUnitStartIndicator = tsScratch.readBit();
tsScratch.skipBits(1); // transport_priority
int pid = tsScratch.readBits(13);
tsScratch.skipBits(2); // transport_scrambling_control
boolean adaptationFieldExists = tsScratch.readBit();
boolean payloadExists = tsScratch.readBit();
// Last 4 bits of scratch are skipped: continuity_counter
// Skip the adaptation field.
if (adaptationFieldExists) {
int adaptationFieldLength = tsPacketBuffer.readUnsignedByte();
tsPacketBuffer.skip(adaptationFieldLength);
}
// Read the payload.
if (payloadExists) {
TsPayloadReader payloadReader = tsPayloadReaders.get(pid);
if (payloadReader != null) {
payloadReader.consume(tsPacketBuffer, payloadUnitStartIndicator);
}
}
if (!prepared) {
prepared = checkPrepared();
}
return bytesRead;
}
// @VisibleForTesting
/* package */ static void appendNumberOfSamples(
ParsableByteArray buffer, long packetSampleCount) {
buffer.setLimit(buffer.limit() + 4);
// The vorbis decoder expects the number of samples in the packet
// to be appended to the audio data as an int32
buffer.data[buffer.limit() - 4] = (byte) ((packetSampleCount) & 0xFF);
buffer.data[buffer.limit() - 3] = (byte) ((packetSampleCount >>> 8) & 0xFF);
buffer.data[buffer.limit() - 2] = (byte) ((packetSampleCount >>> 16) & 0xFF);
buffer.data[buffer.limit() - 1] = (byte) ((packetSampleCount >>> 24) & 0xFF);
}
@Override
public void consume(ParsableByteArray data, boolean payloadUnitStartIndicator) {
if (payloadUnitStartIndicator) {
switch (state) {
case STATE_FINDING_HEADER:
case STATE_READING_HEADER:
// Expected.
break;
case STATE_READING_HEADER_EXTENSION:
Log.w(TAG, "Unexpected start indicator reading extended header");
break;
case STATE_READING_BODY:
// If payloadSize == -1 then the length of the previous packet was unspecified, and so
// we only know that it's finished now that we've seen the start of the next one. This
// is expected. If payloadSize != -1, then the length of the previous packet was known,
// but we didn't receive that amount of data. This is not expected.
if (payloadSize != -1) {
Log.w(TAG, "Unexpected start indicator: expected " + payloadSize + " more bytes");
}
// Either way, if the body was started, notify the reader that it has now finished.
if (bodyStarted) {
pesPayloadReader.packetFinished();
}
break;
}
setState(STATE_READING_HEADER);
}
while (data.bytesLeft() > 0) {
switch (state) {
case STATE_FINDING_HEADER:
data.skip(data.bytesLeft());
break;
case STATE_READING_HEADER:
if (continueRead(data, pesScratch.getData(), HEADER_SIZE)) {
setState(parseHeader() ? STATE_READING_HEADER_EXTENSION : STATE_FINDING_HEADER);
}
break;
case STATE_READING_HEADER_EXTENSION:
int readLength = Math.min(MAX_HEADER_EXTENSION_SIZE, extendedHeaderLength);
// Read as much of the extended header as we're interested in, and skip the rest.
if (continueRead(data, pesScratch.getData(), readLength)
&& continueRead(data, null, extendedHeaderLength)) {
parseHeaderExtension();
bodyStarted = false;
setState(STATE_READING_BODY);
}
break;
case STATE_READING_BODY:
readLength = data.bytesLeft();
int padding = payloadSize == -1 ? 0 : readLength - payloadSize;
if (padding > 0) {
readLength -= padding;
data.setLimit(data.getPosition() + readLength);
}
pesPayloadReader.consume(data, timeUs, !bodyStarted);
bodyStarted = true;
if (payloadSize != -1) {
payloadSize -= readLength;
if (payloadSize == 0) {
pesPayloadReader.packetFinished();
setState(STATE_READING_HEADER);
}
}
break;
}
}
}