Cadence/c++/carla-backend/carla_engine_rtaudio.cpp

/*
 * Carla Backend
 * Copyright (C) 2012 Filipe Coelho <falktx@falktx.com>
 *
 * 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
 * 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.
 *
 * For a full copy of the GNU General Public License see the COPYING file
 */

#ifdef CARLA_ENGINE_RTAUDIO

#include "carla_engine.h"
#include "carla_plugin.h"

CARLA_BACKEND_START_NAMESPACE

// -------------------------------------------------------------------------------------------------------------------
// static RtAudio<->Engine calls

static int carla_rtaudio_process_callback(void* outputBuffer, void* inputBuffer, unsigned int nframes, double streamTime, RtAudioStreamStatus status, void* userData)
{
    CarlaEngineRtAudio* const engine = (CarlaEngineRtAudio*)userData;
    engine->handleProcessCallback(outputBuffer, inputBuffer, nframes, streamTime, status);
    return 0;
}

// -------------------------------------------------------------------------------------------------------------------
// Carla Engine (RtAudio)

CarlaEngineRtAudio::CarlaEngineRtAudio(RtAudio::Api api)
    : CarlaEngine(),
      adac(api)
{
    qDebug("CarlaEngineRtAudio::CarlaEngineRtAudio()");

    type = CarlaEngineTypeRtAudio;
}

CarlaEngineRtAudio::~CarlaEngineRtAudio()
{
    qDebug("CarlaEngineRtAudio::~CarlaEngineRtAudio()");
}

bool CarlaEngineRtAudio::init(const char* const clientName)
{
    qDebug("CarlaEngineRtAudio::init(\"%s\")", clientName);

    if (adac.getDeviceCount() < 1)
    {
        setLastError("No audio devices available");
        return false;
    }

    sampleRate = 48000;
    unsigned int rtBufferFrames = 512;

    RtAudio::StreamParameters iParams, oParams;
    //iParams.deviceId = 3;
    //oParams.deviceId = 2;
    iParams.nChannels = 2;
    oParams.nChannels = 2;
    RtAudio::StreamOptions options;
    options.flags = /*RTAUDIO_NONINTERLEAVED |*/ RTAUDIO_MINIMIZE_LATENCY /*| RTAUDIO_HOG_DEVICE*/ | RTAUDIO_SCHEDULE_REALTIME | RTAUDIO_ALSA_USE_DEFAULT;
    options.streamName = clientName;
    options.priority = 85;

    try {
        adac.openStream(&oParams, &iParams, RTAUDIO_FLOAT32, sampleRate, &rtBufferFrames, carla_rtaudio_process_callback, this, &options);
    }
    catch (RtError& e)
    {
        setLastError(e.what());
        return false;
    }

    bufferSize = rtBufferFrames;

    // set client name, fixed for OSC usage
    // FIXME - put this in shared?
    char* fixedName = strdup(clientName);
    for (size_t i=0; i < strlen(fixedName); i++)
    {
        if (! (std::isalpha(fixedName[i]) || std::isdigit(fixedName[i])))
            fixedName[i] = '_';
    }
    name = strdup(fixedName);
    free((void*)fixedName);

    qDebug("RtAudio bufferSize = %i", bufferSize);

    try {
        adac.startStream();
    }
    catch (RtError& e)
    {
        setLastError(e.what());
        return false;
    }

    CarlaEngine::init(name);

    return true;
}

bool CarlaEngineRtAudio::close()
{
    qDebug("CarlaEngineRtAudio::close()");
    CarlaEngine::close();

    if (name)
    {
        free((void*)name);
        name = nullptr;
    }

    if (adac.isStreamRunning())
        adac.stopStream();

    if (adac.isStreamOpen())
        adac.closeStream();

    return true;
}

bool CarlaEngineRtAudio::isOffline()
{
    return false;
}

bool CarlaEngineRtAudio::isRunning()
{
    return adac.isStreamRunning();
}

CarlaEngineClient* CarlaEngineRtAudio::addClient(CarlaPlugin* const plugin)
{
    CarlaEngineClientNativeHandle handle;
    handle.type = type;

//    unsigned int rtBufferFrames = getBufferSize();

//    RtAudio::StreamParameters iParams, oParams;
//    iParams.nChannels = plugin->audioInCount();
//    oParams.nChannels = plugin->audioOutCount();
//    RtAudio::StreamOptions options;
//    options.flags = /*RTAUDIO_NONINTERLEAVED |*/ RTAUDIO_MINIMIZE_LATENCY /*| RTAUDIO_HOG_DEVICE*/ | RTAUDIO_SCHEDULE_REALTIME | RTAUDIO_ALSA_USE_DEFAULT;
//    options.streamName = plugin->name();
//    options.priority = 85;

//    try {
//        adac.openStream(&oParams, &iParams, RTAUDIO_FLOAT32, getSampleRate(), &rtBufferFrames, carla_rtaudio_process_callback, this, &options);
//    }
//    catch (RtError& e)
//    {
//        setLastError(e.what());
//        return false;
//    }

    return new CarlaEngineClient(handle);
    Q_UNUSED(plugin);
}

// -------------------------------------------------------------------------------------------------------------------

void CarlaEngineRtAudio::handleProcessCallback(void* outputBuffer, void* inputBuffer, unsigned int nframes, double streamTime, RtAudioStreamStatus status)
{
    if (maxPluginNumber() == 0)
        return;

    // get buffers from RtAudio
    float* insPtr  = (float*)inputBuffer;
    float* outsPtr = (float*)outputBuffer;

    // assert buffers
    CARLA_ASSERT(insPtr);
    CARLA_ASSERT(outsPtr);

    // create temporary audio buffers
    float inBuf1[nframes];
    float inBuf2[nframes];
    float outBuf1[nframes];
    float outBuf2[nframes];

    // initialize audio input
    for (unsigned int i=0; i < nframes*2; i++)
    {
        if (i % 2)
            inBuf2[i/2] = insPtr[i];
        else
            inBuf1[i/2] = insPtr[i];
    }

    // create (real) audio buffers
    float* inBuf[2]  = { inBuf1, inBuf2 };
    float* outBuf[2] = { outBuf1, outBuf2 };

    // initialize control input
    memset(rackControlEventsIn, 0, sizeof(CarlaEngineControlEvent)*MAX_ENGINE_CONTROL_EVENTS);
    {
        // TODO
    }

    // initialize midi input
    memset(rackMidiEventsIn, 0, sizeof(CarlaEngineMidiEvent)*MAX_ENGINE_MIDI_EVENTS);
    {
        // TODO
    }

    processRack(inBuf, outBuf, nframes);

    // output audio
    for (unsigned int i=0; i < nframes*2; i++)
    {
        if (i % 2)
            outsPtr[i] = outBuf2[i/2];
        else
            outsPtr[i] = outBuf1[i/2];
    }

    // output control
    {
        // TODO
    }

    // output midi
    {
        // TODO
    }

    Q_UNUSED(streamTime);
    Q_UNUSED(status);
}

CARLA_BACKEND_END_NAMESPACE

#endif // CARLA_ENGINE_RTAUDIO