package org.kc7bfi.jflac;
/**
* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2000,2001,2002,2003 Josh Coalson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
import org.kc7bfi.jflac.frame.*;
import org.kc7bfi.jflac.io.BitInputStream;
import org.kc7bfi.jflac.metadata.*;
import org.kc7bfi.jflac.util.ByteData;
import org.kc7bfi.jflac.util.CRC16;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;
/**
* A Java FLAC decoder.
*
* @author kc7bfi
*/
public class FLACDecoder {
private static final int FRAME_FOOTER_CRC_LEN = 16; // bits
private static final byte[] ID3V2_TAG = new byte[]{'I', 'D', '3'};
private BitInputStream bitStream;
private ChannelData[] channelData = new ChannelData[Constants.MAX_CHANNELS];
private int outputCapacity = 0;
private int outputChannels = 0;
private int lastFrameNumber;
private long samplesDecoded = 0;
private StreamInfo streamInfo;
private Frame frame = new Frame();
private byte[] headerWarmup = new byte[2]; // contains the sync code and reserved bits
//private int state;
private int channels;
private int channelAssignment;
private int bitsPerSample;
private int sampleRate; // in Hz
private int blockSize; // in samples (per channel)
private InputStream inputStream = null;
private int badFrames;
private boolean eof = false;
private FrameListeners frameListeners = new FrameListeners();
private PCMProcessors pcmProcessors = new PCMProcessors();
/**
* The constructor.
*
* @param inputStream The input stream to read data from
*/
public FLACDecoder(InputStream inputStream) {
this.inputStream = inputStream;
this.bitStream = new BitInputStream(inputStream);
lastFrameNumber = 0;
samplesDecoded = 0;
}
/**
* Return the parsed StreamInfo Metadata record.
*
* @return The StreamInfo
*/
public StreamInfo getStreamInfo() {
return streamInfo;
}
/**
* Return the ChannelData object.
*
* @return The ChannelData object
*/
public ChannelData[] getChannelData() {
return channelData;
}
/**
* Return the input but stream.
*
* @return The bit stream
*/
public BitInputStream getBitInputStream() {
return bitStream;
}
/**
* Add a frame listener.
*
* @param listener The frame listener to add
*/
public void addFrameListener(FrameListener listener) {
frameListeners.addFrameListener(listener);
}
/**
* Remove a frame listener.
*
* @param listener The frame listener to remove
*/
public void removeFrameListener(FrameListener listener) {
frameListeners.removeFrameListener(listener);
}
/**
* Add a PCM processor.
*
* @param processor The processor listener to add
*/
public void addPCMProcessor(PCMProcessor processor) {
pcmProcessors.addPCMProcessor(processor);
}
/**
* Remove a PCM processor.
*
* @param processor The processor listener to remove
*/
public void removePCMProcessor(PCMProcessor processor) {
pcmProcessors.removePCMProcessor(processor);
}
private void callPCMProcessors(Frame frame) {
ByteData bd = decodeFrame(frame, null);
pcmProcessors.processPCM(bd);
}
/**
* Fill the given ByteData object with PCM data from the frame.
*
* @param frame the frame to send to the PCM processors
* @param pcmData the byte data to be filled, or null if it should be allocated
* @return the ByteData that was filled (may be a new instance from <code>space</code>)
*/
public ByteData decodeFrame(Frame frame, ByteData pcmData) {
// required size of the byte buffer
int byteSize = frame.header.blockSize * channels * ((streamInfo.getBitsPerSample() / 8));
if (pcmData == null || pcmData.getData().length < byteSize) {
pcmData = new ByteData(byteSize);
} else {
pcmData.setLen(0);
}
if (streamInfo.getBitsPerSample() == 8) {
for (int i = 0; i < frame.header.blockSize; i++) {
for (int channel = 0; channel < channels; channel++) {
pcmData.append((byte) (channelData[channel].getOutput()[i] + 0x80));
}
}
} else if (streamInfo.getBitsPerSample() == 16) {
for (int i = 0; i < frame.header.blockSize; i++) {
for (int channel = 0; channel < channels; channel++) {
short val = (short) (channelData[channel].getOutput()[i]);
pcmData.append((byte) (val & 0xff));
pcmData.append((byte) ((val >> 8) & 0xff));
}
}
} else if (streamInfo.getBitsPerSample() == 24) {
for (int i = 0; i < frame.header.blockSize; i++) {
for (int channel = 0; channel < channels; channel++) {
int val = (channelData[channel].getOutput()[i]);
pcmData.append((byte) (val & 0xff));
pcmData.append((byte) ((val >> 8) & 0xff));
pcmData.append((byte) ((val >> 16) & 0xff));
}
}
}
return pcmData;
}
/**
* Read the FLAC stream info.
*
* @return The FLAC Stream Info record
* @throws IOException On read error
*/
public StreamInfo readStreamInfo() throws IOException {
readStreamSync();
Metadata metadata = readNextMetadata();
if (!(metadata instanceof StreamInfo)) throw new IOException("StreamInfo metadata block missing");
return (StreamInfo) metadata;
}
/**
* Read an array of metadata blocks.
*
* @return The array of metadata blocks
* @throws IOException On read error
*/
public Metadata[] readMetadata() throws IOException {
readStreamSync();
Vector<Metadata> metadataList = new Vector<Metadata>();
Metadata metadata;
do {
metadata = readNextMetadata();
metadataList.add(metadata);
} while (!metadata.isLast());
return metadataList.toArray(new Metadata[metadataList.size()]);
}
/**
* Read an array of metadata blocks.
*
* @param streamInfo The StreamInfo metadata block previously read
* @return The array of metadata blocks
* @throws IOException On read error
*/
public Metadata[] readMetadata(StreamInfo streamInfo) throws IOException {
if (streamInfo.isLast()) return new Metadata[0];
Vector<Metadata> metadataList = new Vector<Metadata>();
Metadata metadata;
do {
metadata = readNextMetadata();
metadataList.add(metadata);
} while (!metadata.isLast());
return metadataList.toArray(new Metadata[metadataList.size()]);
}
/**
* Decode the data frames.
*
* @throws IOException On read error
*/
public void decodeFrames() throws IOException {
try {
while (true) {
findFrameSync();
try {
readFrame();
frameListeners.processFrame(frame);
callPCMProcessors(frame);
} catch (FrameDecodeException e) {
badFrames++;
}
}
} catch (EOFException e) {
eof = true;
}
}
/**
* Read the next data frame.
*
* @return The next frame
* @throws IOException on read error
*/
public Frame readNextFrame() throws IOException {
try {
while (true) {
findFrameSync();
try {
readFrame();
return frame;
} catch (FrameDecodeException e) {
badFrames++;
if (badFrames > 10)
return null;
}
}
} catch (EOFException e) {
eof = true;
}
return null;
}
/**
* Bytes read.
*
* @return The number of bytes read
*/
public long getTotalBytesRead() {
return bitStream.getTotalBytesRead();
}
private void allocateOutput(int size, int channels) {
if (size <= outputCapacity && channels <= outputChannels) return;
for (int i = 0; i < Constants.MAX_CHANNELS; i++) {
channelData[i] = null;
}
for (int i = 0; i < channels; i++) {
channelData[i] = new ChannelData(size);
}
outputCapacity = size;
outputChannels = channels;
}
/**
* Read the stream sync string.
*
* @throws IOException On read error
*/
private void readStreamSync() throws IOException {
int id = 0;
for (int i = 0; i < 4;) {
int x = bitStream.readRawUInt(8);
if (x == Constants.STREAM_SYNC_STRING[i]) {
i++;
id = 0;
} else if (x == ID3V2_TAG[id]) {
id++;
i = 0;
if (id == 3) {
skipID3v2Tag();
id = 0;
}
} else {
throw new IOException("Could not find Stream Sync");
}
}
}
/**
* Read a single metadata record.
*
* @return The next metadata record
* @throws IOException on read error
*/
public Metadata readNextMetadata() throws IOException {
Metadata metadata;
boolean isLast = (bitStream.readRawUInt(Metadata.STREAM_METADATA_IS_LAST_LEN) != 0);
int type = bitStream.readRawUInt(Metadata.STREAM_METADATA_TYPE_LEN);
int length = bitStream.readRawUInt(Metadata.STREAM_METADATA_LENGTH_LEN);
if (type == Metadata.METADATA_TYPE_STREAMINFO) {
streamInfo = new StreamInfo(bitStream, length, isLast);
metadata = streamInfo;
pcmProcessors.processStreamInfo((StreamInfo) metadata);
} else if (type == Metadata.METADATA_TYPE_SEEKTABLE) {
metadata = new SeekTable(bitStream, length, isLast);
} else if (type == Metadata.METADATA_TYPE_APPLICATION) {
metadata = new Application(bitStream, length, isLast);
} else if (type == Metadata.METADATA_TYPE_PADDING) {
metadata = new Padding(bitStream, length, isLast);
} else if (type == Metadata.METADATA_TYPE_VORBIS_COMMENT) {
metadata = new VorbisComment(bitStream, length, isLast);
} else if (type == Metadata.METADATA_TYPE_CUESHEET) {
metadata = new CueSheet(bitStream, length, isLast);
} else if (type == Metadata.METADATA_TYPE_PICTURE) {
metadata = new Picture(bitStream, length, isLast);
} else {
metadata = new Unknown(bitStream, length, isLast);
}
frameListeners.processMetadata(metadata);
//if (isLast) state = DECODER_SEARCH_FOR_FRAME_SYNC;
return metadata;
}
private void skipID3v2Tag() throws IOException {
// skip the version and flags bytes
int verMajor = bitStream.readRawInt(8);
int verMinor = bitStream.readRawInt(8);
int flags = bitStream.readRawInt(8);
// get the size (in bytes) to skip
int skip = 0;
for (int i = 0; i < 4; i++) {
int x = bitStream.readRawUInt(8);
skip <<= 7;
skip |= (x & 0x7f);
}
// skip the rest of the tag
bitStream.readByteBlockAlignedNoCRC(null, skip);
}
private void findFrameSync() throws IOException {
boolean first = true;
//int cnt=0;
// If we know the total number of samples in the stream, stop if we've read that many.
// This will stop us, for example, from wasting time trying to sync on an ID3V1 tag.
if (streamInfo != null && (streamInfo.getTotalSamples() != 0)) {
if (samplesDecoded >= streamInfo.getTotalSamples()) {
//state = DECODER_END_OF_STREAM;
return;
}
}
// make sure we're byte aligned
if (!bitStream.isConsumedByteAligned()) {
bitStream.readRawUInt(bitStream.bitsLeftForByteAlignment());
}
int x;
try {
while (true) {
x = bitStream.readRawUInt(8);
if (x == 0xff) { // MAGIC NUMBER for the first 8 frame sync bits
headerWarmup[0] = (byte) x;
x = bitStream.peekRawUInt(8);
/* we have to check if we just read two 0xff's in a row; the second may actually be the beginning of the sync code */
/* else we have to check if the second byte is the end of a sync code */
if (x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */
headerWarmup[1] = (byte) bitStream.readRawUInt(8);
//state = DECODER_READ_FRAME;
return;
}
}
if (first) {
frameListeners.processError("FindSync LOST_SYNC: " + Integer.toHexString((x & 0xff)));
first = false;
}
}
} catch (EOFException e) {
if (!first) frameListeners.processError("FindSync LOST_SYNC: Left over data in file");
//state = DECODER_END_OF_STREAM;
}
}
/**
* Read the next data frame.
*
* @throws IOException On read error
* @throws FrameDecodeException On frame decoding error
*/
public void readFrame() throws IOException, FrameDecodeException {
boolean gotAFrame = false;
int channel;
int i;
int mid, side, left, right;
short frameCRC; /* the one we calculate from the input stream */
//int x;
/* init the CRC */
frameCRC = 0;
frameCRC = CRC16.update(headerWarmup[0], frameCRC);
frameCRC = CRC16.update(headerWarmup[1], frameCRC);
bitStream.resetReadCRC16(frameCRC);
try {
frame.header = new Header(bitStream, headerWarmup, streamInfo);
} catch (BadHeaderException e) {
frameListeners.processError("Found bad header: " + e);
throw new FrameDecodeException("Bad Frame Header: " + e);
}
//if (state == DECODER_SEARCH_FOR_FRAME_SYNC) return false;
allocateOutput(frame.header.blockSize, frame.header.channels);
for (channel = 0; channel < frame.header.channels; channel++) {
// first figure the correct bits-per-sample of the subframe
int bps = frame.header.bitsPerSample;
switch (frame.header.channelAssignment) {
case Constants.CHANNEL_ASSIGNMENT_INDEPENDENT:
/* no adjustment needed */
break;
case Constants.CHANNEL_ASSIGNMENT_LEFT_SIDE:
if (channel == 1)
bps++;
break;
case Constants.CHANNEL_ASSIGNMENT_RIGHT_SIDE:
if (channel == 0)
bps++;
break;
case Constants.CHANNEL_ASSIGNMENT_MID_SIDE:
if (channel == 1)
bps++;
break;
default:
}
// now read it
try {
readSubframe(channel, bps);
} catch (IOException e) {
frameListeners.processError("ReadSubframe: " + e);
throw e;
}
}
readZeroPadding();
// Read the frame CRC-16 from the footer and check
frameCRC = bitStream.getReadCRC16();
frame.setCRC((short) bitStream.readRawUInt(FRAME_FOOTER_CRC_LEN));
if (frameCRC == frame.getCRC()) {
/* Undo any special channel coding */
switch (frame.header.channelAssignment) {
case Constants.CHANNEL_ASSIGNMENT_INDEPENDENT:
/* do nothing */
break;
case Constants.CHANNEL_ASSIGNMENT_LEFT_SIDE:
for (i = 0; i < frame.header.blockSize; i++)
channelData[1].getOutput()[i] = channelData[0].getOutput()[i] - channelData[1].getOutput()[i];
break;
case Constants.CHANNEL_ASSIGNMENT_RIGHT_SIDE:
for (i = 0; i < frame.header.blockSize; i++)
channelData[0].getOutput()[i] += channelData[1].getOutput()[i];
break;
case Constants.CHANNEL_ASSIGNMENT_MID_SIDE:
for (i = 0; i < frame.header.blockSize; i++) {
mid = channelData[0].getOutput()[i];
side = channelData[1].getOutput()[i];
mid <<= 1;
if ((side & 1) != 0) // i.e. if 'side' is odd...
mid++;
left = mid + side;
right = mid - side;
channelData[0].getOutput()[i] = left >> 1;
channelData[1].getOutput()[i] = right >> 1;
}
//System.exit(1);
break;
default:
break;
}
gotAFrame = true;
} else {
// Bad frame, emit error and zero the output signal
frameListeners.processError("CRC Error: " + Integer.toHexString((frameCRC & 0xffff)) + " vs " + Integer.toHexString((frame.getCRC() & 0xffff)));
for (channel = 0; channel < frame.header.channels; channel++) {
for (int j = 0; j < frame.header.blockSize; j++)
channelData[channel].getOutput()[j] = 0;
}
}
// put the latest values into the public section of the decoder instance
channels = frame.header.channels;
channelAssignment = frame.header.channelAssignment;
bitsPerSample = frame.header.bitsPerSample;
sampleRate = frame.header.sampleRate;
blockSize = frame.header.blockSize;
samplesDecoded += frame.header.blockSize;
}
private void readSubframe(int channel, int bps) throws IOException, FrameDecodeException {
int x;
x = bitStream.readRawUInt(8); /* MAGIC NUMBER */
boolean haveWastedBits = ((x & 1) != 0);
x &= 0xfe;
int wastedBits = 0;
if (haveWastedBits) {
wastedBits = bitStream.readUnaryUnsigned() + 1;
bps -= wastedBits;
}
// Lots of magic numbers here
if ((x & 0x80) != 0) {
frameListeners.processError("ReadSubframe LOST_SYNC: " + Integer.toHexString(x & 0xff));
//state = DECODER_SEARCH_FOR_FRAME_SYNC;
throw new FrameDecodeException("ReadSubframe LOST_SYNC: " + Integer.toHexString(x & 0xff));
//return true;
} else if (x == 0) {
frame.subframes[channel] = new ChannelConstant(bitStream, frame.header, channelData[channel], bps, wastedBits);
} else if (x == 2) {
frame.subframes[channel] = new ChannelVerbatim(bitStream, frame.header, channelData[channel], bps, wastedBits);
} else if (x < 16) {
//state = DECODER_UNPARSEABLE_STREAM;
throw new FrameDecodeException("ReadSubframe Bad Subframe Type: " + Integer.toHexString(x & 0xff));
} else if (x <= 24) {
//FLACSubframe_Fixed subframe = read_subframe_fixed_(channel, bps, (x >> 1) & 7);
frame.subframes[channel] = new ChannelFixed(bitStream, frame.header, channelData[channel], bps, wastedBits, (x >> 1) & 7);
} else if (x < 64) {
//state = DECODER_UNPARSEABLE_STREAM;
throw new FrameDecodeException("ReadSubframe Bad Subframe Type: " + Integer.toHexString(x & 0xff));
} else {
frame.subframes[channel] = new ChannelLPC(bitStream, frame.header, channelData[channel], bps, wastedBits, ((x >> 1) & 31) + 1);
}
if (haveWastedBits) {
int i;
x = frame.subframes[channel].getWastedBits();
for (i = 0; i < frame.header.blockSize; i++)
channelData[channel].getOutput()[i] <<= x;
}
}
private void readZeroPadding() throws IOException, FrameDecodeException {
if (!bitStream.isConsumedByteAligned()) {
int zero = bitStream.readRawUInt(bitStream.bitsLeftForByteAlignment());
if (zero != 0) {
frameListeners.processError("ZeroPaddingError: " + Integer.toHexString(zero));
//state = DECODER_SEARCH_FOR_FRAME_SYNC;
throw new FrameDecodeException("ZeroPaddingError: " + Integer.toHexString(zero));
}
}
}
/**
* Get the number of samples decoded.
*
* @return Returns the samples Decoded.
*/
public long getSamplesDecoded() {
return samplesDecoded;
}
/**
* @return Returns the number of bad frames decoded.
*/
public int getBadFrames() {
return badFrames;
}
/**
* @return Returns true if end-of-file.
*/
public boolean isEOF() {
return eof;
}
public void flush() {
samplesDecoded = 0;
}
}