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Diffstat (limited to 'backends/audiocd/audiocd-stream.cpp')
| -rw-r--r-- | backends/audiocd/audiocd-stream.cpp | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/backends/audiocd/audiocd-stream.cpp b/backends/audiocd/audiocd-stream.cpp new file mode 100644 index 0000000000..3c0d0957da --- /dev/null +++ b/backends/audiocd/audiocd-stream.cpp @@ -0,0 +1,199 @@ +/* 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. + * + * Original license header: + * + * Cabal - Legacy Game Implementations + * + * Cabal 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 "backends/audiocd/audiocd-stream.h" +#include "common/textconsole.h" + +AudioCDStream::AudioCDStream() : _buffer(), _frame(0), _bufferPos(0), _bufferFrame(0), _forceStop(false) { +} + +AudioCDStream::~AudioCDStream() { + // Stop the timer; the subclass needs to do this, + // so this is just a last resort. + stopTimer(); + + // Clear any buffered frames + emptyQueue(); +} + +int AudioCDStream::readBuffer(int16 *buffer, const int numSamples) { + int samples = 0; + + // See if any data is left first + while (_bufferPos < kSamplesPerFrame && samples < numSamples) + buffer[samples++] = _buffer[_bufferPos++]; + + // Bail out if done + if (endOfData()) + return samples; + + while (samples < numSamples && !endOfData()) { + if (!readNextFrame()) + return samples; + + // Copy the samples over + for (_bufferPos = 0; _bufferPos < kSamplesPerFrame && samples < numSamples;) + buffer[samples++] = _buffer[_bufferPos++]; + } + + return samples; +} + +bool AudioCDStream::readNextFrame() { + // Fetch a frame from the queue + int16 *buffer; + + { + Common::StackLock lock(_mutex); + + // Nothing we can do if it's empty + if (_bufferQueue.empty()) + return false; + + buffer = _bufferQueue.pop(); + } + + memcpy(_buffer, buffer, kSamplesPerFrame * 2); + delete[] buffer; + _frame++; + return true; +} + +bool AudioCDStream::endOfData() const { + return !shouldForceStop() && getStartFrame() + _frame >= getEndFrame() && _bufferPos == kSamplesPerFrame; +} + +bool AudioCDStream::seek(const Audio::Timestamp &where) { + // Stop the timer + stopTimer(); + + // Clear anything out of the queue + emptyQueue(); + + // Convert to the frame number + // Really not much else needed + _bufferPos = kSamplesPerFrame; + _frame = where.convertToFramerate(kFramesPerSecond).totalNumberOfFrames(); + _bufferFrame = _frame; + + // Start the timer again + startTimer(); + return true; +} + +Audio::Timestamp AudioCDStream::getLength() const { + return Audio::Timestamp(0, getEndFrame() - getStartFrame(), kFramesPerSecond); +} + +void AudioCDStream::timerProc(void *refCon) { + static_cast<AudioCDStream *>(refCon)->onTimer(); +} + +void AudioCDStream::onTimer() { + // The goal here is to do as much work in this timer instead + // of doing it in the readBuffer() call, which is the mixer. + + // If we're done, bail. + if (shouldForceStop() || getStartFrame() + _bufferFrame >= getEndFrame()) + return; + + // Get a quick count of the number of items in the queue + // We don't care that much; we only need a quick estimate + _mutex.lock(); + uint32 queueCount = _bufferQueue.size(); + _mutex.unlock(); + + // If we have enough audio buffered, bail out + if (queueCount >= kBufferThreshold) + return; + + while (!shouldForceStop() && queueCount < kBufferThreshold && getStartFrame() + _bufferFrame < getEndFrame()) { + int16 *buffer = new int16[kSamplesPerFrame]; + + // Figure out the MSF of the frame we're looking for + int frame = _bufferFrame + getStartFrame(); + + // Request to read that frame + if (!readFrame(frame, buffer)) { + warning("Failed to read CD audio"); + forceStop(); + return; + } + + _bufferFrame++; + + // Now push the buffer onto the queue + Common::StackLock lock(_mutex); + _bufferQueue.push(buffer); + queueCount = _bufferQueue.size(); + } +} + +void AudioCDStream::startTimer(bool fillBuffer) { + _forceStop = false; + if (fillBuffer) { + onTimer(); + } + g_system->getTimerManager()->installTimerProc(timerProc, 10 * 1000, this, "AudioCDStream"); +} + +void AudioCDStream::stopTimer() { + forceStop(); + g_system->getTimerManager()->removeTimerProc(timerProc); +} + +void AudioCDStream::emptyQueue() { + while (!_bufferQueue.empty()) + delete[] _bufferQueue.pop(); +} + +bool AudioCDStream::shouldForceStop() const { + Common::StackLock lock(_forceStopMutex); + return _forceStop; +} + +void AudioCDStream::forceStop() { + Common::StackLock lock(_forceStopMutex); + _forceStop = true; +} |