AudioEngine.h

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/*
 * AudioEngine.h - device-independent audio engine for LMMS
 *
 * Copyright (c) 2004-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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 (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef LMMS_AUDIO_ENGINE_H
#define LMMS_AUDIO_ENGINE_H
 
#include <mutex>
 
#include <QThread>
#include <samplerate.h>
 
#include <memory>
#include <vector>
 
#include "AudioBufferView.h"
#include "AudioDevice.h"
#include "LmmsTypes.h"
#include "SampleFrame.h"
#include "LocklessList.h"
#include "AudioEngineProfiler.h"
#include "PlayHandle.h"
 
 
namespace lmms
{
 
class MidiClient;
class AudioBusHandle;  // IWYU pragma: keep
class AudioEngineWorkerThread;
 
constexpr f_cnt_t MINIMUM_BUFFER_SIZE = 32;
constexpr f_cnt_t DEFAULT_BUFFER_SIZE = 256;
constexpr f_cnt_t MAXIMUM_BUFFER_SIZE = 4096;
 
constexpr int BYTES_PER_SAMPLE = sizeof(sample_t);
constexpr int BYTES_PER_INT_SAMPLE = sizeof(int_sample_t);
constexpr int BYTES_PER_FRAME = sizeof(SampleFrame);
 
constexpr float OUTPUT_SAMPLE_MULTIPLIER = 32767.0f;
 
constexpr auto SUPPORTED_SAMPLERATES = std::array{44100, 48000, 88200, 96000, 192000};
constexpr auto SUPPORTED_BITRATES = std::array{64, 128, 160, 192, 256, 320};
 
class LMMS_EXPORT AudioEngine : public QObject
{
        Q_OBJECT
public:
        class RequestChangesGuard {
                friend class AudioEngine;
 
        private:
                RequestChangesGuard(AudioEngine* audioEngine)
                        : m_audioEngine{audioEngine}
                {
                        m_audioEngine->requestChangeInModel();
                }
        public:
 
                RequestChangesGuard()
                        : m_audioEngine{nullptr}
                {
                }
 
                RequestChangesGuard(RequestChangesGuard&& other)
                        : RequestChangesGuard()
                {
                        std::swap(other.m_audioEngine, m_audioEngine);
                }
 
                // Disallow copy.
                RequestChangesGuard(const RequestChangesGuard&) = delete;
                RequestChangesGuard& operator=(const RequestChangesGuard&) = delete;
 
                ~RequestChangesGuard() {
                        if (m_audioEngine) {
                                m_audioEngine->doneChangeInModel();
                        }
                }
 
        private:
                AudioEngine* m_audioEngine;
        };
 
        void initDevices();
        void clear();
        void clearNewPlayHandles();
 
 
        // audio-device-stuff
 
        bool renderOnly() const { return m_renderOnly; }
        // Returns the current audio device's name. This is not necessarily
        // the user's preferred audio device, in case you were thinking that.
        inline const QString & audioDevName() const
        {
                return m_audioDevName;
        }
        inline bool audioDevStartFailed() const
        {
                return m_audioDevStartFailed;
        }

        void setAudioDevice(AudioDevice* _dev, bool startNow);
        void storeAudioDevice();
        void restoreAudioDevice();
        inline AudioDevice * audioDev()
        {
                return m_audioDev;
        }
 
 
        // audio-bus-handle-stuff
        inline void addAudioBusHandle(AudioBusHandle* busHandle)
        {
                requestChangeInModel();
                m_audioBusHandles.push_back(busHandle);
                doneChangeInModel();
        }
 
        void removeAudioBusHandle(AudioBusHandle* busHandle);
 
 
        // MIDI-client-stuff
        inline const QString & midiClientName() const
        {
                return m_midiClientName;
        }
 
        inline MidiClient * midiClient()
        {
                return m_midiClient;
        }
 
 
        // play-handle stuff
        bool addPlayHandle( PlayHandle* handle );
 
        void removePlayHandle( PlayHandle* handle );
 
        inline PlayHandleList& playHandles()
        {
                return m_playHandles;
        }
 
        void removePlayHandlesOfTypes(Track * track, PlayHandle::Types types);
 
        AudioEngineProfiler& profiler()
        {
                return m_profiler;
        }
 
        int cpuLoad() const
        {
                return m_profiler.cpuLoad();
        }
 
        int detailLoad(const AudioEngineProfiler::DetailType type) const
        {
                return m_profiler.detailLoad(type);
        }
 
        sample_rate_t baseSampleRate() const { return m_baseSampleRate; }
 
 
        sample_rate_t outputSampleRate() const
        {
                return m_audioDev != nullptr ? m_audioDev->sampleRate() : m_baseSampleRate;
        }
        
 
        sample_rate_t inputSampleRate() const   
        {
                return m_audioDev != nullptr ? m_audioDev->sampleRate() : m_baseSampleRate;
        }
 
 
        inline float masterGain() const
        {
                return m_masterGain;
        }
 
        inline void setMasterGain(const float mo)
        {
                m_masterGain = mo;
        }
 
 
        static inline sample_t clip(const sample_t s)
        {
                if (s > 1.0f)
                {
                        return 1.0f;
                }
                else if (s < -1.0f)
                {
                        return -1.0f;
                }
                return s;
        }
 
 
        bool criticalXRuns() const;
 
        void pushInputFrames( SampleFrame* _ab, const f_cnt_t _frames );
 
        inline const SampleFrame* inputBuffer()
        {
                return m_inputBuffer[ m_inputBufferRead ];
        }
 
        inline f_cnt_t inputBufferFrames() const
        {
                return m_inputBufferFrames[ m_inputBufferRead ];
        }

        f_cnt_t framesPerPeriod() const { return m_framesPerPeriod; }

        f_cnt_t framesPerAudioBuffer() const { return m_framesPerAudioBuffer; }

        std::span<const SampleFrame> renderNextPeriod();

        void renderNextBuffer(InterleavedBufferView<float> dst) { renderNextBuffer<InterleavedBufferView<float>>(dst); }

        void renderNextBuffer(PlanarBufferView<float> dst) { renderNextBuffer<PlanarBufferView<float>>(dst); }

        void requestChangeInModel();
        void doneChangeInModel();
 
        RequestChangesGuard requestChangesGuard()
        {
                return RequestChangesGuard{this};
        }
 
        static bool isAudioDevNameValid(QString name);
        static bool isMidiDevNameValid(QString name);
 
 
signals:
        void qualitySettingsChanged();
        void sampleRateChanged();
        void nextAudioBuffer(const lmms::SampleFrame* buffer);
 
 
private:
        void renderNextBuffer(AudioBufferView<float> auto dst)
        {
                for (auto frame = f_cnt_t{0}; frame < dst.frames(); ++frame)
                {
                        if (m_outputBufferReadIndex == m_framesPerPeriod) { m_outputBufferReadIndex = 0; }
                        if (m_outputBufferReadIndex == 0) { renderNextPeriod(); }
 
                        switch (dst.channels())
                        {
                        case 0:
                                assert(false);
                                break;
                        case 1:
                                dst.sample(0, frame) = m_outputBufferRead[m_outputBufferReadIndex].average();
                                break;
                        case 2:
                                dst.sample(0, frame) = m_outputBufferRead[m_outputBufferReadIndex][0];
                                dst.sample(1, frame) = m_outputBufferRead[m_outputBufferReadIndex][1];
                                break;
                        default:
                                dst.sample(0, frame) = m_outputBufferRead[m_outputBufferReadIndex][0];
                                dst.sample(1, frame) = m_outputBufferRead[m_outputBufferReadIndex][1];
                                for (auto channel = 2; channel < dst.channels(); ++channel)
                                {
                                        dst.sample(channel, frame) = 0.f;
                                }
                                break;
                        }
 
                        ++m_outputBufferReadIndex;
                }
        }
 
        AudioEngine( bool renderOnly );
        ~AudioEngine() override;
 
        void startProcessing() { m_audioDev->startProcessing(); }
        void stopProcessing() { m_audioDev->stopProcessing(); }
 
 
        AudioDevice * tryAudioDevices();
        MidiClient * tryMidiClients();
 
        void renderStageNoteSetup();
        void renderStageInstruments();
        void renderStageEffects();
        void renderStageMix();
 
 
        void swapBuffers();
 
        void clearInternal();
 
        bool m_renderOnly;
 
        std::vector<AudioBusHandle*> m_audioBusHandles;
 
        f_cnt_t m_framesPerAudioBuffer;
        f_cnt_t m_framesPerPeriod;
        sample_rate_t m_baseSampleRate;
 
        SampleFrame* m_inputBuffer[2];
        f_cnt_t m_inputBufferFrames[2];
        f_cnt_t m_inputBufferSize[2];
        int m_inputBufferRead;
        int m_inputBufferWrite;
 
        std::unique_ptr<SampleFrame[]> m_outputBufferRead;
        std::unique_ptr<SampleFrame[]> m_outputBufferWrite;
        f_cnt_t m_outputBufferReadIndex;
 
        // worker thread stuff
        std::vector<AudioEngineWorkerThread *> m_workers;
        int m_numWorkers;
 
        // playhandle stuff
        PlayHandleList m_playHandles;
        // place where new playhandles are added temporarily
        LocklessList<PlayHandle *> m_newPlayHandles;
        ConstPlayHandleList m_playHandlesToRemove;
 
        float m_masterGain;
 
        // audio device stuff
        void doSetAudioDevice( AudioDevice *_dev );
        AudioDevice * m_audioDev;
        AudioDevice * m_oldAudioDev;
        QString m_audioDevName;
        bool m_audioDevStartFailed;
 
        // MIDI device stuff
        MidiClient * m_midiClient;
        QString m_midiClientName;
 
        AudioEngineProfiler m_profiler;
 
        bool m_clearSignal;
 
        std::recursive_mutex m_changeMutex;
 
        friend class Engine;
        friend class AudioEngineWorkerThread;
        friend class ProjectRenderer;
} ;
 
} // namespace lmms
 
#endif // LMMS_AUDIO_ENGINE_H