PortAudioDriver.cpp

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/*
 * Hydrogen
 * Copyright(c) 2002-2008 by Alex >Comix< Cominu [comix@users.sourceforge.net]
 * Copyright(c) 2008-2025 The hydrogen development team [hydrogen-devel@lists.sourceforge.net]
 *
 * http://www.hydrogen-music.org
 *
 * 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, see https://www.gnu.org/licenses
 *
 */
 
#include <core/IO/PortAudioDriver.h>
#if defined(H2CORE_HAVE_PORTAUDIO) || _DOXYGEN_
 
#include <iostream>
 
#include <core/Preferences/Preferences.h>
namespace H2Core
{
 
int portAudioCallback(
        const void *inputBuffer,
        void *outputBuffer,
        unsigned long framesPerBuffer,
        const PaStreamCallbackTimeInfo* timeInfo,
        PaStreamCallbackFlags statusFlags,
        void *userData )
{
        float *out = ( float* )outputBuffer;
        PortAudioDriver *pDriver = ( PortAudioDriver* )userData;
        if ( pDriver == nullptr ) {
                ___ERRORLOG( "Invalid driver pointer" );
                return 1;
        }
 
        while ( framesPerBuffer > 0 ) {
                unsigned long nFrames = std::min( (unsigned long) MAX_BUFFER_SIZE, framesPerBuffer );
                pDriver->m_processCallback( nFrames, nullptr );
 
                for ( unsigned i = 0; i < nFrames; i++ ) {
                        *out++ = pDriver->m_pOut_L[ i ];
                        *out++ = pDriver->m_pOut_R[ i ];
                }
                framesPerBuffer -= nFrames;
        }
        return 0;
}
 
 
bool PortAudioDriver::m_bInitialised = false;
 
 
PortAudioDriver::PortAudioDriver( audioProcessCallback processCallback )
                : AudioOutput()
                , m_processCallback( processCallback )
                , m_pOut_L( nullptr )
                , m_pOut_R( nullptr )
                , m_pStream( nullptr )
{
        m_nSampleRate = Preferences::get_instance()->m_nSampleRate;
        m_sDevice = Preferences::get_instance()->m_sPortAudioDevice;
}
 
 
PortAudioDriver::~PortAudioDriver() {
}
 
int PortAudioDriver::init( unsigned nBufferSize )
{
        return 0;
}
 
 
// String list of API names
QStringList PortAudioDriver::getHostAPIs()
{
        if ( ! m_bInitialised ) {
                Pa_Initialize();
                m_bInitialised = true;
        }
 
        QStringList hostAPIs;
        int nHostAPIs = Pa_GetHostApiCount();
        for ( int n = 0; n < nHostAPIs; n++ ) {
                const PaHostApiInfo *pHostApiInfo = Pa_GetHostApiInfo( (PaHostApiIndex)n );
                if ( pHostApiInfo == nullptr ) {
                        ERRORLOG( QString( "Invalid host API [%1]" ).arg( n ) );
                        continue;
                }
                hostAPIs.push_back( pHostApiInfo->name );
        }
 
        return hostAPIs;
}
        
// List devices
QStringList PortAudioDriver::getDevices( QString HostAPI ) {
        if ( ! m_bInitialised ) {
                Pa_Initialize();
                m_bInitialised = true;
        }
 
        QStringList devices;
        if ( HostAPI.isNull() || HostAPI == "" ) {
                WARNINGLOG( "Using default HostAPI" );
                auto pInfo = Pa_GetHostApiInfo( Pa_GetDefaultHostApi() );
                if ( pInfo == nullptr ) {
                        ERRORLOG( "Unable to obtain default Host API" );
                        return devices;
                }
                
                HostAPI = pInfo->name;
        }
 
        int nDevices = Pa_GetDeviceCount();
        for ( int nDevice = 0; nDevice < nDevices; nDevice++ ) {
                const PaDeviceInfo *pDeviceInfo = Pa_GetDeviceInfo( nDevice );
                if ( pDeviceInfo == nullptr ) {
                        continue;
                }
 
                // Filter by API
                auto pInfo = Pa_GetHostApiInfo( pDeviceInfo->hostApi );
                if ( pInfo == nullptr || pInfo->name != HostAPI ) {
                        continue;
                }
                if ( pDeviceInfo->maxOutputChannels >= 2 ) {
                        devices.push_back( QString( pDeviceInfo->name ) );
                }
        }
 
        return devices;
}
 
QStringList PortAudioDriver::getDevices() {
        Preferences *pPreferences = Preferences::get_instance();
        return getDevices( pPreferences->m_sPortAudioHostAPI );
}
 
//
// Connect
// return 0: Ok
// return 1: Generic error
//
int PortAudioDriver::connect()
{
        bool bUseDefaultStream = true;
        Preferences *pPreferences = Preferences::get_instance();
        INFOLOG( "[connect]" );
 
        m_pOut_L = new float[ MAX_BUFFER_SIZE ];
        m_pOut_R = new float[ MAX_BUFFER_SIZE ];
 
        // Reset buffers to avoid noise during startup (e.g. in case the callback
        // was not able to obtain the audio engine lock, the arbitrary numbers
        // filling the buffer after creation will be passed to the audio output).
        for ( int ii = 0; ii < MAX_BUFFER_SIZE; ii++ ) {
                m_pOut_L[ ii ] = 0;
                m_pOut_R[ ii ] = 0;
        }
 
        int err;
        if ( ! m_bInitialised ) {
                err = Pa_Initialize();
 
                if ( err != paNoError ) {
                        ERRORLOG( "Portaudio error in Pa_Initialize: " + QString( Pa_GetErrorText( err ) ) );
                        return 1;
                }
                m_bInitialised = true;
 
        }
 
 
        // Find device to use
        int nDevices = Pa_GetDeviceCount();
        const PaDeviceInfo *pDeviceInfo;
        for ( int nDevice = 0; nDevice < nDevices; nDevice++ ) {
                pDeviceInfo = Pa_GetDeviceInfo( nDevice );
                if ( pDeviceInfo == nullptr ) {
                        continue;
                }
                
                // Filter by HostAPI
                if ( ! pPreferences->m_sPortAudioHostAPI.isNull() || pPreferences->m_sPortAudioHostAPI != "" ) {
                        auto pInfo = Pa_GetHostApiInfo( pDeviceInfo->hostApi );
                        if ( pInfo == nullptr || pInfo->name != pPreferences->m_sPortAudioHostAPI ) {
                                continue;
                        }
                }
 
                if ( pDeviceInfo->maxOutputChannels >= 2
                         && ( QString::compare( m_sDevice,  pDeviceInfo->name, Qt::CaseInsensitive ) == 0 ||
                              m_sDevice.isNull() || m_sDevice == "" ) ) {
                        PaStreamParameters outputParameters;
                        memset( &outputParameters, '\0', sizeof( outputParameters ) );
                        outputParameters.channelCount = 2;
                        outputParameters.device = nDevice;
                        outputParameters.hostApiSpecificStreamInfo = nullptr;
                        outputParameters.sampleFormat = paFloat32;
 
                        // Use the same latency setting as Pa_OpenDefaultStream() -- defaulting to the high suggested
                        // latency. This should probably be an option.
                        outputParameters.suggestedLatency =
                                Pa_GetDeviceInfo( nDevice )->defaultHighInputLatency;
                        if ( pPreferences->m_nLatencyTarget > 0 ) {
                                outputParameters.suggestedLatency = pPreferences->m_nLatencyTarget * 1.0 / getSampleRate();
                        }
 
                        err = Pa_OpenStream( &m_pStream,
                                                                 nullptr, /* No input stream */
                                                                 &outputParameters,
                                                                 m_nSampleRate, paFramesPerBufferUnspecified, paNoFlag,
                                                                 portAudioCallback, this );
                        if ( err != paNoError ) {
                                ERRORLOG( QString( "Found but can't open device '%1' (max %3 in, %4 out): %2" )
                                                  .arg( m_sDevice ).arg( Pa_GetErrorText( err ) )
                                                  .arg( pDeviceInfo->maxInputChannels ).arg( pDeviceInfo->maxOutputChannels ) );
                                // Use the default stream
                                break;
                        }
                        INFOLOG( QString( "Opened device '%1'" ).arg( m_sDevice ) );
                        bUseDefaultStream = false;
                        break;
                }
 
                if ( bUseDefaultStream ) {
                        ERRORLOG( QString( "Can't use device '%1', using default stream" )
                                          .arg( m_sDevice ) );
                }
        }
 
        if ( bUseDefaultStream ) {
                // Failed to open the request device. Use the default device.
                // Less than desirably, this will also use the default latency settings.
                err = Pa_OpenDefaultStream(
                                        &m_pStream,        /* passes back stream pointer */
                                        0,              /* no input channels */
                                        2,              /* stereo output */
                                        paFloat32,      /* 32 bit floating point output */
                                        m_nSampleRate,          // sample rate
                                        paFramesPerBufferUnspecified, // frames per buffer
                                        portAudioCallback, /* specify our custom callback */
                                        this );        /* pass our data through to callback */
        }
 
        if ( err != paNoError ) {
                ERRORLOG(  "Portaudio error in Pa_OpenDefaultStream: " + QString( Pa_GetErrorText( err ) ) );
                return 1;
        }
 
        if ( m_pStream == nullptr ) {
                ERRORLOG( "Invalid stream." );
                return 1;
        }
 
        const PaStreamInfo *pStreamInfo = Pa_GetStreamInfo( m_pStream );
        if ( pStreamInfo == nullptr ) {
                ERRORLOG( "Invalid stream info." );
                return 1;
        }
        
        if ( (unsigned) pStreamInfo->sampleRate != m_nSampleRate ) {
                ERRORLOG( QString( "Couldn't get sample rate %d, using %d instead" ).arg( m_nSampleRate ).arg( pStreamInfo->sampleRate ) );
                m_nSampleRate = (unsigned) pStreamInfo->sampleRate;
        }
        INFOLOG( QString( "PortAudio outpot latency: %1 s" ).arg( pStreamInfo->outputLatency ) );
 
        err = Pa_StartStream( m_pStream );
 
 
        if ( err != paNoError ) {
                ERRORLOG(  "Portaudio error in Pa_StartStream: " + QString( Pa_GetErrorText( err ) ) );
                return 1;
        }
        return 0;
}
 
void PortAudioDriver::disconnect()
{
        if ( m_pStream != nullptr ) {
                
                int err = Pa_StopStream( m_pStream );
                if ( err != paNoError ) {
                        ERRORLOG( "Err: " + QString( Pa_GetErrorText( err ) ) );
                }
 
                err = Pa_CloseStream( m_pStream );
                if ( err != paNoError ) {
                        ERRORLOG( "Err: " + QString( Pa_GetErrorText( err ) ) );
                }
        }
 
        m_bInitialised = false;
        Pa_Terminate();
 
        delete[] m_pOut_L;
        m_pOut_L = nullptr;
 
        delete[] m_pOut_R;
        m_pOut_R = nullptr;
}
 
unsigned PortAudioDriver::getBufferSize()
{
        return MAX_BUFFER_SIZE;
}
 
unsigned PortAudioDriver::getSampleRate()
{
        return m_nSampleRate;
}
 
int PortAudioDriver::getLatency()
{
        if ( m_pStream == nullptr ) {
                return 0;
        }
        
        const PaStreamInfo *pStreamInfo = Pa_GetStreamInfo( m_pStream );
        if ( pStreamInfo == nullptr ) {
                ERRORLOG( "Invalid stream info" );
                return 0;
        }
        
        return std::max( static_cast<int>( pStreamInfo->outputLatency * getSampleRate() ),
                                         0 );
}
 
float* PortAudioDriver::getOut_L()
{
        return m_pOut_L;
}
 
float* PortAudioDriver::getOut_R()
{
        return m_pOut_R;
}
 
};
 
#endif