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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.
*
*/
#include "common/scummsys.h"
#include "common/endian.h"
#include "common/memstream.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "audio/audiostream.h"
#include "engines/zvision/zork_raw.h"
namespace ZVision {
#pragma mark -
#pragma mark --- RawZorkStream ---
#pragma mark -
/**
* This is a stream, which allows for playing raw PCM data from a stream.
*/
class RawZorkStream : public Audio::SeekableAudioStream {
public:
RawZorkStream(int rate, DisposeAfterUse::Flag disposeStream, Common::SeekableReadStream *stream)
: _rate(rate), _playtime(0, rate), _stream(stream, disposeStream), _endOfData(false), _buffer(0) {
// Setup our buffer for readBuffer
_buffer = new byte[kSampleBufferLength];
assert(_buffer);
// Calculate the total playtime of the stream
_playtime = Audio::Timestamp(0, _stream->size() / 2 / 1, rate);
}
~RawZorkStream() {
delete[] _buffer;
}
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const { return true; }
bool endOfData() const { return _endOfData; }
int getRate() const { return _rate; }
Audio::Timestamp getLength() const { return _playtime; }
bool seek(const Audio::Timestamp &where);
private:
const int _rate; ///< Sample rate of stream
Audio::Timestamp _playtime; ///< Calculated total play time
Common::DisposablePtr<Common::SeekableReadStream> _stream; ///< Stream to read data from
bool _endOfData; ///< Whether the stream end has been reached
byte *_buffer; ///< Buffer used in readBuffer
enum {
/**
* How many samples we can buffer at once.
*
* TODO: Check whether this size suffices
* for systems with slow disk I/O.
*/
kSampleBufferLength = 2048
};
/**
* Fill the temporary sample buffer used in readBuffer.
*
* @param maxSamples Maximum samples to read.
* @return actual count of samples read.
*/
int fillBuffer(int maxSamples);
};
int RawZorkStream::readBuffer(int16 *buffer, const int numSamples) {
int samplesLeft = numSamples;
while (samplesLeft > 0) {
// Try to read up to "samplesLeft" samples.
int len = fillBuffer(samplesLeft);
// In case we were not able to read any samples
// we will stop reading here.
if (!len)
break;
// Adjust the samples left to read.
samplesLeft -= len;
// Copy the data to the caller's buffer.
const byte *src = _buffer;
while (len-- > 0) {
if (*src < 128)
*buffer++ = ((128 - *src) << 8) ^ 0x8000;
else
*buffer++ = (*src << 8) ^ 0x8000;
src++;
}
}
return numSamples - samplesLeft;
}
int RawZorkStream::fillBuffer(int maxSamples) {
int bufferedSamples = 0;
byte *dst = _buffer;
// We can only read up to "kSampleBufferLength" samples
// so we take this into consideration, when trying to
// read up to maxSamples.
maxSamples = MIN<int>(kSampleBufferLength, maxSamples);
// We will only read up to maxSamples
while (maxSamples > 0 && !endOfData()) {
// Try to read all the sample data and update the
// destination pointer.
const int bytesRead = _stream->read(dst, maxSamples);
dst += bytesRead;
// Calculate how many samples we actually read.
const int samplesRead = bytesRead;
// Update all status variables
bufferedSamples += samplesRead;
maxSamples -= samplesRead;
// We stop stream playback, when we reached the end of the data stream.
// We also stop playback when an error occures.
if (_stream->pos() == _stream->size() || _stream->err() || _stream->eos())
_endOfData = true;
}
return bufferedSamples;
}
bool RawZorkStream::seek(const Audio::Timestamp &where) {
_endOfData = true;
if (where > _playtime)
return false;
const uint32 seekSample = convertTimeToStreamPos(where, getRate(), isStereo()).totalNumberOfFrames();
_stream->seek(seekSample, SEEK_SET);
// In case of an error we will not continue stream playback.
if (!_stream->err() && !_stream->eos() && _stream->pos() != _stream->size())
_endOfData = false;
return true;
}
#pragma mark -
#pragma mark --- Raw stream factories ---
#pragma mark -
Audio::SeekableAudioStream *makeRawZorkStream(Common::SeekableReadStream *stream,
int rate,
DisposeAfterUse::Flag disposeAfterUse) {
assert(stream->size() % 2 == 0);
return new RawZorkStream(rate, disposeAfterUse, stream);
}
Audio::SeekableAudioStream *makeRawZorkStream(const byte *buffer, uint32 size,
int rate,
DisposeAfterUse::Flag disposeAfterUse) {
return makeRawZorkStream(new Common::MemoryReadStream(buffer, size, disposeAfterUse), rate, DisposeAfterUse::YES);
}
} // End of namespace ZVision
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