mixer.cpp

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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 "gui/EventRecorder.h"

#include "common/util.h"
#include "common/system.h"
#include "common/textconsole.h"

#include "audio/mixer_intern.h"
#include "audio/rate.h"
#include "audio/audiostream.h"
#include "audio/timestamp.h"


namespace Audio {

#pragma mark -
#pragma mark --- Channel classes ---
#pragma mark -


class Channel {
public:
    Channel(Mixer *mixer, Mixer::SoundType type, AudioStream *stream, DisposeAfterUse::Flag autofreeStream, bool reverseStereo, int id, bool permanent);
    ~Channel();

    int mix(int16 *data, uint len);

    bool isFinished() const { return _stream->endOfStream(); }

    bool isPermanent() const { return _permanent; }

    int getId() const { return _id; }

    void pause(bool paused);

    bool isPaused() const { return (_pauseLevel != 0); }

    void setVolume(const byte volume);

    byte getVolume();

    void setBalance(const int8 balance);

    int8 getBalance();

    void notifyGlobalVolChange() { updateChannelVolumes(); }

    Timestamp getElapsedTime();

    Mixer::SoundType getType() const { return _type; }

    void setHandle(const SoundHandle handle) { _handle = handle; }

    SoundHandle getHandle() const { return _handle; }

private:
    const Mixer::SoundType _type;
    SoundHandle _handle;
    bool _permanent;
    int _pauseLevel;
    int _id;

    byte _volume;
    int8 _balance;

    void updateChannelVolumes();
    st_volume_t _volL, _volR;

    Mixer *_mixer;

    uint32 _samplesConsumed;
    uint32 _samplesDecoded;
    uint32 _mixerTimeStamp;
    uint32 _pauseStartTime;
    uint32 _pauseTime;

    RateConverter *_converter;
    Common::DisposablePtr<AudioStream> _stream;
};

#pragma mark -
#pragma mark --- Mixer ---
#pragma mark -

// TODO: parameter "system" is unused
MixerImpl::MixerImpl(OSystem *system, uint sampleRate)
    : _mutex(), _sampleRate(sampleRate), _mixerReady(false), _handleSeed(0), _soundTypeSettings() {

    assert(sampleRate > 0);

    for (int i = 0; i != NUM_CHANNELS; i++)
        _channels[i] = 0;
}

MixerImpl::~MixerImpl() {
    for (int i = 0; i != NUM_CHANNELS; i++)
        delete _channels[i];
}

void MixerImpl::setReady(bool ready) {
    _mixerReady = ready;
}

uint MixerImpl::getOutputRate() const {
    return _sampleRate;
}

void MixerImpl::insertChannel(SoundHandle *handle, Channel *chan) {
    int index = -1;
    for (int i = 0; i != NUM_CHANNELS; i++) {
        if (_channels[i] == 0) {
            index = i;
            break;
        }
    }
    if (index == -1) {
        warning("MixerImpl::out of mixer slots");
        delete chan;
        return;
    }

    _channels[index] = chan;

    SoundHandle chanHandle;
    chanHandle._val = index + (_handleSeed * NUM_CHANNELS);

    chan->setHandle(chanHandle);
    _handleSeed++;
    if (handle)
        *handle = chanHandle;
}

void MixerImpl::playStream(
            SoundType type,
            SoundHandle *handle,
            AudioStream *stream,
            int id, byte volume, int8 balance,
            DisposeAfterUse::Flag autofreeStream,
            bool permanent,
            bool reverseStereo) {
    Common::StackLock lock(_mutex);

    if (stream == 0) {
        warning("stream is 0");
        return;
    }


    assert(_mixerReady);

    // Prevent duplicate sounds
    if (id != -1) {
        for (int i = 0; i != NUM_CHANNELS; i++)
            if (_channels[i] != 0 && _channels[i]->getId() == id) {
                // Delete the stream if were asked to auto-dispose it.
                // Note: This could cause trouble if the client code does not
                // yet expect the stream to be gone. The primary example to
                // keep in mind here is QueuingAudioStream.
                // Thus, as a quick rule of thumb, you should never, ever,
                // try to play QueuingAudioStreams with a sound id.
                if (autofreeStream == DisposeAfterUse::YES)
                    delete stream;
                return;
            }
    }

#ifdef AUDIO_REVERSE_STEREO
    reverseStereo = !reverseStereo;
#endif

    // Create the channel
    Channel *chan = new Channel(this, type, stream, autofreeStream, reverseStereo, id, permanent);
    chan->setVolume(volume);
    chan->setBalance(balance);
    insertChannel(handle, chan);
}

int MixerImpl::mixCallback(byte *samples, uint len) {
    assert(samples);

    Common::StackLock lock(_mutex);

    int16 *buf = (int16 *)samples;
    // we store stereo, 16-bit samples
    assert(len % 4 == 0);
    len >>= 2;

    // Since the mixer callback has been called, the mixer must be ready...
    _mixerReady = true;

    //  zero the buf
    memset(buf, 0, 2 * len * sizeof(int16));

    // mix all channels
    int res = 0, tmp;
    for (int i = 0; i != NUM_CHANNELS; i++)
        if (_channels[i]) {
            if (_channels[i]->isFinished()) {
                delete _channels[i];
                _channels[i] = 0;
            } else if (!_channels[i]->isPaused()) {
                tmp = _channels[i]->mix(buf, len);

                if (tmp > res)
                    res = tmp;
            }
        }

    return res;
}

void MixerImpl::stopAll() {
    Common::StackLock lock(_mutex);
    for (int i = 0; i != NUM_CHANNELS; i++) {
        if (_channels[i] != 0 && !_channels[i]->isPermanent()) {
            delete _channels[i];
            _channels[i] = 0;
        }
    }
}

void MixerImpl::stopID(int id) {
    Common::StackLock lock(_mutex);
    for (int i = 0; i != NUM_CHANNELS; i++) {
        if (_channels[i] != 0 && _channels[i]->getId() == id) {
            delete _channels[i];
            _channels[i] = 0;
        }
    }
}

void MixerImpl::stopHandle(SoundHandle handle) {
    Common::StackLock lock(_mutex);

    // Simply ignore stop requests for handles of sounds that already terminated
    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return;

    delete _channels[index];
    _channels[index] = 0;
}

void MixerImpl::muteSoundType(SoundType type, bool mute) {
    assert(0 <= (int)type && (int)type < ARRAYSIZE(_soundTypeSettings));
    _soundTypeSettings[type].mute = mute;

    for (int i = 0; i != NUM_CHANNELS; ++i) {
        if (_channels[i] && _channels[i]->getType() == type)
            _channels[i]->notifyGlobalVolChange();
    }
}

bool MixerImpl::isSoundTypeMuted(SoundType type) const {
    assert(0 <= (int)type && (int)type < ARRAYSIZE(_soundTypeSettings));
    return _soundTypeSettings[type].mute;
}

void MixerImpl::setChannelVolume(SoundHandle handle, byte volume) {
    Common::StackLock lock(_mutex);

    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return;

    _channels[index]->setVolume(volume);
}

byte MixerImpl::getChannelVolume(SoundHandle handle) {
    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return 0;

    return _channels[index]->getVolume();
}

void MixerImpl::setChannelBalance(SoundHandle handle, int8 balance) {
    Common::StackLock lock(_mutex);

    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return;

    _channels[index]->setBalance(balance);
}

int8 MixerImpl::getChannelBalance(SoundHandle handle) {
    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return 0;

    return _channels[index]->getBalance();
}

uint32 MixerImpl::getSoundElapsedTime(SoundHandle handle) {
    return getElapsedTime(handle).msecs();
}

Timestamp MixerImpl::getElapsedTime(SoundHandle handle) {
    Common::StackLock lock(_mutex);

    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return Timestamp(0, _sampleRate);

    return _channels[index]->getElapsedTime();
}

void MixerImpl::pauseAll(bool paused) {
    Common::StackLock lock(_mutex);
    for (int i = 0; i != NUM_CHANNELS; i++) {
        if (_channels[i] != 0) {
            _channels[i]->pause(paused);
        }
    }
}

void MixerImpl::pauseID(int id, bool paused) {
    Common::StackLock lock(_mutex);
    for (int i = 0; i != NUM_CHANNELS; i++) {
        if (_channels[i] != 0 && _channels[i]->getId() == id) {
            _channels[i]->pause(paused);
            return;
        }
    }
}

void MixerImpl::pauseHandle(SoundHandle handle, bool paused) {
    Common::StackLock lock(_mutex);

    // Simply ignore (un)pause requests for sounds that already terminated
    const int index = handle._val % NUM_CHANNELS;
    if (!_channels[index] || _channels[index]->getHandle()._val != handle._val)
        return;

    _channels[index]->pause(paused);
}

bool MixerImpl::isSoundIDActive(int id) {
    Common::StackLock lock(_mutex);

#ifdef ENABLE_EVENTRECORDER
    g_eventRec.updateSubsystems();
#endif

    for (int i = 0; i != NUM_CHANNELS; i++)
        if (_channels[i] && _channels[i]->getId() == id)
            return true;
    return false;
}

int MixerImpl::getSoundID(SoundHandle handle) {
    Common::StackLock lock(_mutex);
    const int index = handle._val % NUM_CHANNELS;
    if (_channels[index] && _channels[index]->getHandle()._val == handle._val)
        return _channels[index]->getId();
    return 0;
}

bool MixerImpl::isSoundHandleActive(SoundHandle handle) {
    Common::StackLock lock(_mutex);

#ifdef ENABLE_EVENTRECORDER
    g_eventRec.updateSubsystems();
#endif

    const int index = handle._val % NUM_CHANNELS;
    return _channels[index] && _channels[index]->getHandle()._val == handle._val;
}

bool MixerImpl::hasActiveChannelOfType(SoundType type) {
    Common::StackLock lock(_mutex);
    for (int i = 0; i != NUM_CHANNELS; i++)
        if (_channels[i] && _channels[i]->getType() == type)
            return true;
    return false;
}

void MixerImpl::setVolumeForSoundType(SoundType type, int volume) {
    assert(0 <= (int)type && (int)type < ARRAYSIZE(_soundTypeSettings));

    // Check range
    volume = CLIP<int>(volume, 0, kMaxMixerVolume);

    // TODO: Maybe we should do logarithmic (not linear) volume
    // scaling? See also Player_V2::setMasterVolume

    Common::StackLock lock(_mutex);
    _soundTypeSettings[type].volume = volume;

    for (int i = 0; i != NUM_CHANNELS; ++i) {
        if (_channels[i] && _channels[i]->getType() == type)
            _channels[i]->notifyGlobalVolChange();
    }
}

int MixerImpl::getVolumeForSoundType(SoundType type) const {
    assert(0 <= (int)type && (int)type < ARRAYSIZE(_soundTypeSettings));

    return _soundTypeSettings[type].volume;
}


#pragma mark -
#pragma mark --- Channel implementations ---
#pragma mark -

Channel::Channel(Mixer *mixer, Mixer::SoundType type, AudioStream *stream,
                 DisposeAfterUse::Flag autofreeStream, bool reverseStereo, int id, bool permanent)
    : _type(type), _mixer(mixer), _id(id), _permanent(permanent), _volume(Mixer::kMaxChannelVolume),
      _balance(0), _pauseLevel(0), _samplesConsumed(0), _samplesDecoded(0), _mixerTimeStamp(0),
      _pauseStartTime(0), _pauseTime(0), _converter(0), _volL(0), _volR(0),
      _stream(stream, autofreeStream) {
    assert(mixer);
    assert(stream);

    // Get a rate converter instance
    _converter = makeRateConverter(_stream->getRate(), mixer->getOutputRate(), _stream->isStereo(), reverseStereo);
}

Channel::~Channel() {
    delete _converter;
}

void Channel::setVolume(const byte volume) {
    _volume = volume;
    updateChannelVolumes();
}

byte Channel::getVolume() {
    return _volume;
}

void Channel::setBalance(const int8 balance) {
    _balance = balance;
    updateChannelVolumes();
}

int8 Channel::getBalance() {
    return _balance;
}

void Channel::updateChannelVolumes() {
    // From the channel balance/volume and the global volume, we compute
    // the effective volume for the left and right channel. Note the
    // slightly odd divisor: the 255 reflects the fact that the maximal
    // value for _volume is 255, while the 127 is there because the
    // balance value ranges from -127 to 127.  The mixer (music/sound)
    // volume is in the range 0 - kMaxMixerVolume.
    // Hence, the vol_l/vol_r values will be in that range, too

    if (!_mixer->isSoundTypeMuted(_type)) {
        int vol = _mixer->getVolumeForSoundType(_type) * _volume;

        if (_balance == 0) {
            _volL = vol / Mixer::kMaxChannelVolume;
            _volR = vol / Mixer::kMaxChannelVolume;
        } else if (_balance < 0) {
            _volL = vol / Mixer::kMaxChannelVolume;
            _volR = ((127 + _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
        } else {
            _volL = ((127 - _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
            _volR = vol / Mixer::kMaxChannelVolume;
        }
    } else {
        _volL = _volR = 0;
    }
}

void Channel::pause(bool paused) {
    //assert((paused && _pauseLevel >= 0) || (!paused && _pauseLevel));

    if (paused) {
        _pauseLevel++;

        if (_pauseLevel == 1)
            _pauseStartTime = g_system->getMillis(true);
    } else if (_pauseLevel > 0) {
        _pauseLevel--;

        if (!_pauseLevel) {
            _pauseTime = (g_system->getMillis(true) - _pauseStartTime);
            _pauseStartTime = 0;
        }
    }
}

Timestamp Channel::getElapsedTime() {
    const uint32 rate = _mixer->getOutputRate();
    uint32 delta = 0;

    Audio::Timestamp ts(0, rate);

    if (_mixerTimeStamp == 0)
        return ts;

    if (isPaused())
        delta = _pauseStartTime - _mixerTimeStamp;
    else
        delta = g_system->getMillis(true) - _mixerTimeStamp - _pauseTime;

    // Convert the number of samples into a time duration.

    ts = ts.addFrames(_samplesConsumed);
    ts = ts.addMsecs(delta);

    // In theory it would seem like a good idea to limit the approximation
    // so that it never exceeds the theoretical upper bound set by
    // _samplesDecoded. Meanwhile, back in the real world, doing so makes
    // the Broken Sword cutscenes noticeably jerkier. I guess the mixer
    // isn't invoked at the regular intervals that I first imagined.

    return ts;
}

int Channel::mix(int16 *data, uint len) {
    assert(_stream);

    int res = 0;
    if (_stream->endOfData()) {
        // TODO: call drain method
    } else {
        assert(_converter);
        _samplesConsumed = _samplesDecoded;
        _mixerTimeStamp = g_system->getMillis(true);
        _pauseTime = 0;
        res = _converter->flow(*_stream, data, len, _volL, _volR);
        _samplesDecoded += res;
    }

    return res;
}

} // End of namespace Audio