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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program 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 General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "sound/mp3.h"
#ifdef USE_MAD
#include "common/debug.h"
#include "common/stream.h"
#include "common/util.h"
#include "sound/audiocd.h"
#include "sound/audiostream.h"
#include <mad.h>
namespace Audio {
#pragma mark -
#pragma mark --- MP3 (MAD) stream ---
#pragma mark -
class MP3InputStream : public SeekableAudioStream {
protected:
enum State {
MP3_STATE_INIT, // Need to init the decoder
MP3_STATE_READY, // ready for processing data
MP3_STATE_EOS // end of data reached (may need to loop)
};
Common::SeekableReadStream *_inStream;
bool _disposeAfterUse;
uint _posInFrame;
State _state;
const mad_timer_t _startTime;
const mad_timer_t _endTime;
mad_timer_t _totalTime;
int32 _totalPlayTime; // Length of one loop iteration
uint32 _length; // Total length of the MP3 stream
uint _numLoops; ///< Number of loops to play
uint _numPlayedLoops; ///< Number of loops which have been played
mad_stream _stream;
mad_frame _frame;
mad_synth _synth;
enum {
BUFFER_SIZE = 5 * 8192
};
// This buffer contains a slab of input data
byte _buf[BUFFER_SIZE + MAD_BUFFER_GUARD];
public:
MP3InputStream(Common::SeekableReadStream *inStream,
bool dispose,
mad_timer_t start = mad_timer_zero,
mad_timer_t end = mad_timer_zero,
uint numLoops = 1);
~MP3InputStream();
int readBuffer(int16 *buffer, const int numSamples);
bool endOfData() const { return _state == MP3_STATE_EOS; }
bool isStereo() const { return MAD_NCHANNELS(&_frame.header) == 2; }
int getRate() const { return _frame.header.samplerate; }
bool seek(const Timestamp &where);
// TODO: Maybe we can have a more precise implementation of this
Timestamp getLength() const { return Timestamp(_totalPlayTime, getRate()); }
void setNumLoops(uint numLoops) {
_numLoops = numLoops;
_numPlayedLoops = 0;
}
uint getNumPlayedLoops() { return _numPlayedLoops; }
protected:
void decodeMP3Data();
void readMP3Data();
void initStream();
void readHeader();
void deinitStream();
};
MP3InputStream::MP3InputStream(Common::SeekableReadStream *inStream, bool dispose, mad_timer_t start, mad_timer_t end, uint numLoops) :
_inStream(inStream),
_disposeAfterUse(dispose),
_numLoops(numLoops),
_posInFrame(0),
_state(MP3_STATE_INIT),
_startTime(start),
_endTime(end),
_totalTime(mad_timer_zero) {
// Make sure that either start < end, or end is zero (indicating "play until end")
assert(mad_timer_compare(_startTime, _endTime) < 0 || mad_timer_sign(_endTime) == 0);
// The MAD_BUFFER_GUARD must always contain zeros (the reason
// for this is that the Layer III Huffman decoder of libMAD
// may read a few bytes beyond the end of the input buffer).
memset(_buf + BUFFER_SIZE, 0, MAD_BUFFER_GUARD);
// Calculate the length of the stream
initStream();
while (_state != MP3_STATE_EOS)
readHeader();
_length = mad_timer_count(_totalTime, MAD_UNITS_MILLISECONDS);
deinitStream();
// Reinit stream
_state = MP3_STATE_INIT;
// Calculate play time
mad_timer_t length;
mad_timer_set(&length, 0, 0, 1000);
mad_timer_add(&length, start);
mad_timer_negate(&length);
if (mad_timer_sign(end) != 0) {
mad_timer_add(&length, end);
} else {
mad_timer_set(&_totalTime, _length / 1000, _length % 1000, 1000);
mad_timer_add(&length, _totalTime);
_totalTime = mad_timer_zero;
}
_totalPlayTime = mad_timer_count(length, MAD_UNITS_MILLISECONDS);
if (mad_timer_sign(length) < 0)
_totalPlayTime = 0;
// Decode the first chunk of data. This is necessary so that _frame
// is setup and isStereo() and getRate() return correct results.
decodeMP3Data();
}
MP3InputStream::~MP3InputStream() {
deinitStream();
if (_disposeAfterUse)
delete _inStream;
}
void MP3InputStream::decodeMP3Data() {
do {
if (_state == MP3_STATE_INIT)
initStream();
if (_state == MP3_STATE_EOS)
return;
// If necessary, load more data into the stream decoder
if (_stream.error == MAD_ERROR_BUFLEN)
readMP3Data();
while (_state == MP3_STATE_READY) {
readHeader();
// If we have not yet reached the start point, skip to the next frame
if (mad_timer_compare(_totalTime, _startTime) < 0)
continue;
// If an end time is specified and we are past it, stop
if (mad_timer_sign(_endTime) > 0 && mad_timer_compare(_totalTime, _endTime) >= 0) {
_state = MP3_STATE_EOS;
break;
}
// Decode the next frame
if (mad_frame_decode(&_frame, &_stream) == -1) {
if (_stream.error == MAD_ERROR_BUFLEN) {
break; // Read more data
} else if (MAD_RECOVERABLE(_stream.error)) {
// Note: we will occasionally see MAD_ERROR_BADDATAPTR errors here.
// These are normal and expected (caused by our frame skipping (i.e. "seeking")
// code above).
debug(6, "MP3InputStream: Recoverable error in mad_frame_decode (%s)", mad_stream_errorstr(&_stream));
continue;
} else {
warning("MP3InputStream: Unrecoverable error in mad_frame_decode (%s)", mad_stream_errorstr(&_stream));
break;
}
}
// Synthesize PCM data
mad_synth_frame(&_synth, &_frame);
_posInFrame = 0;
break;
}
if (_state == MP3_STATE_EOS) {
++_numPlayedLoops;
// If looping is on and there are loops left, rewind to the start
if (!_numLoops || _numPlayedLoops < _numLoops) {
deinitStream();
// Reset the decoder state to indicate we should start over
_state = MP3_STATE_INIT;
}
}
} while (_state != MP3_STATE_EOS && _stream.error == MAD_ERROR_BUFLEN);
if (_stream.error != MAD_ERROR_NONE)
_state = MP3_STATE_EOS;
}
void MP3InputStream::readMP3Data() {
uint32 remaining = 0;
// Give up immediately if we already used up all data in the stream
if (_inStream->eos()) {
_state = MP3_STATE_EOS;
return;
}
if (_stream.next_frame) {
// If there is still data in the MAD stream, we need to preserve it.
// Note that we use memmove, as we are reusing the same buffer,
// and hence the data regions we copy from and to may overlap.
remaining = _stream.bufend - _stream.next_frame;
assert(remaining < BUFFER_SIZE); // Paranoia check
memmove(_buf, _stream.next_frame, remaining);
}
// Try to read the next block
uint32 size = _inStream->read(_buf + remaining, BUFFER_SIZE - remaining);
if (size <= 0) {
_state = MP3_STATE_EOS;
return;
}
// Feed the data we just read into the stream decoder
_stream.error = MAD_ERROR_NONE;
mad_stream_buffer(&_stream, _buf, size + remaining);
}
bool MP3InputStream::seek(const Timestamp &where) {
const uint32 time = where.msecs();
if (time == _length) {
_state = MP3_STATE_EOS;
return true;
} else if (time > _length) {
return false;
}
mad_timer_t destination;
mad_timer_set(&destination, time / 1000, time % 1000, 1000);
if (_state != MP3_STATE_READY || mad_timer_compare(destination, _totalTime) < 0)
initStream();
while (mad_timer_compare(destination, _totalTime) > 0 && _state != MP3_STATE_EOS)
readHeader();
return (_state != MP3_STATE_EOS);
}
void MP3InputStream::initStream() {
if (_state != MP3_STATE_INIT)
deinitStream();
// Init MAD
mad_stream_init(&_stream);
mad_frame_init(&_frame);
mad_synth_init(&_synth);
// Reset the stream data
_inStream->seek(0, SEEK_SET);
_totalTime = mad_timer_zero;
_posInFrame = 0;
// Update state
_state = MP3_STATE_READY;
// Read the first few sample bytes
readMP3Data();
}
void MP3InputStream::readHeader() {
if (_state != MP3_STATE_READY)
return;
// If necessary, load more data into the stream decoder
if (_stream.error == MAD_ERROR_BUFLEN)
readMP3Data();
while (_state != MP3_STATE_EOS) {
_stream.error = MAD_ERROR_NONE;
// Decode the next header. Note: mad_frame_decode would do this for us, too.
// However, for seeking we don't want to decode the full frame (else it would
// be far too slow). Hence we perform this explicitly in a separate step.
if (mad_header_decode(&_frame.header, &_stream) == -1) {
if (_stream.error == MAD_ERROR_BUFLEN) {
readMP3Data(); // Read more data
continue;
} else if (MAD_RECOVERABLE(_stream.error)) {
debug(6, "MP3InputStream: Recoverable error in mad_header_decode (%s)", mad_stream_errorstr(&_stream));
continue;
} else {
warning("MP3InputStream: Unrecoverable error in mad_header_decode (%s)", mad_stream_errorstr(&_stream));
break;
}
}
// Sum up the total playback time so far
mad_timer_add(&_totalTime, _frame.header.duration);
break;
}
if (_stream.error != MAD_ERROR_NONE)
_state = MP3_STATE_EOS;
}
void MP3InputStream::deinitStream() {
if (_state == MP3_STATE_INIT)
return;
// Deinit MAD
mad_synth_finish(&_synth);
mad_frame_finish(&_frame);
mad_stream_finish(&_stream);
_state = MP3_STATE_EOS;
}
static inline int scale_sample(mad_fixed_t sample) {
// round
sample += (1L << (MAD_F_FRACBITS - 16));
// clip
if (sample > MAD_F_ONE - 1)
sample = MAD_F_ONE - 1;
else if (sample < -MAD_F_ONE)
sample = -MAD_F_ONE;
// quantize and scale to not saturate when mixing a lot of channels
return sample >> (MAD_F_FRACBITS + 1 - 16);
}
int MP3InputStream::readBuffer(int16 *buffer, const int numSamples) {
int samples = 0;
// Keep going as long as we have input available
while (samples < numSamples && _state != MP3_STATE_EOS) {
const int len = MIN(numSamples, samples + (int)(_synth.pcm.length - _posInFrame) * MAD_NCHANNELS(&_frame.header));
while (samples < len) {
*buffer++ = (int16)scale_sample(_synth.pcm.samples[0][_posInFrame]);
samples++;
if (MAD_NCHANNELS(&_frame.header) == 2) {
*buffer++ = (int16)scale_sample(_synth.pcm.samples[1][_posInFrame]);
samples++;
}
_posInFrame++;
}
if (_posInFrame >= _synth.pcm.length) {
// We used up all PCM data in the current frame -- read & decode more
decodeMP3Data();
}
}
return samples;
}
#pragma mark -
#pragma mark --- MP3 factory functions ---
#pragma mark -
SeekableAudioStream *makeMP3Stream(
Common::SeekableReadStream *stream,
bool disposeAfterUse,
uint32 startTime,
uint32 duration,
uint numLoops) {
mad_timer_t start;
mad_timer_t end;
// Both startTime and duration are given in milliseconds.
// Calculate the appropriate mad_timer_t values from them.
mad_timer_set(&start, startTime / 1000, startTime % 1000, 1000);
if (duration == 0) {
end = mad_timer_zero;
} else {
int endTime = startTime + duration;
mad_timer_set(&end, endTime / 1000, endTime % 1000, 1000);
}
return new MP3InputStream(stream, disposeAfterUse, start, end, numLoops);
}
} // End of namespace Audio
#endif // #ifdef USE_MAD
|