OssDriver.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/OssDriver.h>
 
// check if OSS support is enabled
#if defined(H2CORE_HAVE_OSS) || _DOXYGEN_
 
#include <core/Preferences/Preferences.h>
 
#include <pthread.h>
 
namespace H2Core
{
 
audioProcessCallback ossDriver_audioProcessCallback;
bool ossDriver_running;
pthread_t ossDriverThread;
int oss_driver_bufferSize = -1;
OssDriver *m_pOssDriverInstance = NULL;
 
unsigned nNextFrames = 0;
 
void* ossDriver_processCaller( void* param )
{
        Base * __object = ( Base * )param;
        // stolen from amSynth
        struct sched_param sched;
        sched.sched_priority = 50;
        int res = sched_setscheduler( 0, SCHED_FIFO, &sched );
        sched_getparam( 0, &sched );
        if ( res ) {
                __WARNINGLOG( "Can't set realtime scheduling for OSS Driver" );
        }
        __INFOLOG( QString( "Scheduling priority = %1" ).arg( sched.sched_priority ) );
 
        OssDriver *ossDriver = ( OssDriver* )param;
 
        sleep( 1 );
 
        while ( ossDriver_running ) {
                ossDriver_audioProcessCallback( oss_driver_bufferSize, NULL );
                ossDriver->write();
        }
 
        pthread_exit( NULL );
        return NULL;
}
 
 
OssDriver::OssDriver( audioProcessCallback processCallback )
                : AudioOutput()
{
        audioBuffer = NULL;
        ossDriver_running = false;
        this->processCallback = processCallback;
        ossDriver_audioProcessCallback = processCallback;
        m_pOssDriverInstance = this;
}
 
 
 
 
 
 
OssDriver::~OssDriver() {
}
 
 
 
int OssDriver::init( unsigned nBufferSize )
{
        oss_driver_bufferSize = nBufferSize;
 
        delete[] audioBuffer;
        audioBuffer = NULL;
 
        audioBuffer = new short[nBufferSize * 2];
 
        out_L = new float[nBufferSize];
        out_R = new float[nBufferSize];
 
        // clear buffers
        memset( out_L, 0, nBufferSize * sizeof( float ) );
        memset( out_R, 0, nBufferSize * sizeof( float ) );
 
        return 0;
}
 
 

int OssDriver::connect()
{
        INFOLOG( "connect" );
 
        Preferences *preferencesMng = Preferences::get_instance();
 
        // initialize OSS
        int bits = 16;
        int speed = preferencesMng->m_nSampleRate;
        int stereo = 1;
        int bs;
 
        QString audioDevice;
#ifdef __NetBSD__
        audioDevice = "/dev/audio";
#else
        audioDevice = preferencesMng->m_sOSSDevice;
#endif
 
        // Non blocking OSS open code stolen from GLAME
        fd = open( audioDevice.toLocal8Bit(), O_WRONLY | O_NONBLOCK );        // test with non blocking open
        int arg = fcntl( fd, F_GETFL, 0 );
        if ( arg != -1 ) {      // back to blocking mode...
                fcntl( fd, F_SETFL, arg & ~O_NONBLOCK );
        }
 
        if ( fd == -1 ) {
                ERRORLOG( "DSP ERROR_OPEN" );
                return 1;
        }
        if ( ioctl( fd, SNDCTL_DSP_SYNC, NULL ) < 0 ) {
                ERRORLOG( "ERROR_IOCTL" );
                close( fd );
                return 1;
        }
        if ( ioctl( fd, SNDCTL_DSP_SAMPLESIZE, &bits ) < 0 ) {
                ERRORLOG( "ERROR_IOCTL" );
                close( fd );
                return 1;
        }
        if ( ioctl( fd, SNDCTL_DSP_SPEED, &speed ) < 0 ) {
                ERRORLOG( "ERROR_IOCTL" );
                close( fd );
                return 1;
        }
        if ( ioctl( fd, SNDCTL_DSP_STEREO, &stereo ) < 0 ) {
                ERRORLOG( "ERROR_IOCTL" );
                close( fd );
                return 1;
        }
 
        unsigned bufferBits = log2( speed / 60 );
        int fragSize = 0x00200000 | bufferBits;
 
        ioctl( fd, SNDCTL_DSP_SETFRAGMENT, &fragSize );
 
        if ( ioctl( fd, SNDCTL_DSP_GETBLKSIZE, &bs ) < 0 ) {
                ERRORLOG( "ERROR_IOCTL" );
                close( fd );
                return 1;
        }
 
        INFOLOG( QString( "Blocksize audio = %1" ).arg( bs ) );
 
                /* commenting this is a fix against buffersize problems described in ticket 119
        if ( bs != ( 1 << bufferBits ) ) {
                ERRORLOG( "ERROR_IOCTL: unable to set BlockSize" );
                close( fd );
                return 1;
        }
                */// end comment
 
        int format = AFMT_S16_LE;
        if ( ioctl( fd, SNDCTL_DSP_SETFMT, &format ) == -1 ) {
                ERRORLOG( "ERROR_IOCTL unable to set format" );
                close( fd );
                return 1;
        }
 
        // start main thread
        ossDriver_running = true;
        pthread_attr_t attr;
        pthread_attr_init( &attr );
 
        pthread_create( &ossDriverThread, &attr, ossDriver_processCaller, this );
 
        return 0;
}
 
 
 
 
void OssDriver::disconnect()
{
        INFOLOG( "disconnect" );
 
        ossDriver_running = false;
 
        // join ossDriverThread
        pthread_join( ossDriverThread, NULL );
 
        if ( fd != -1 ) {
                if ( close( fd ) ) {
                        ERRORLOG( "Error closing audio device" );
                }
        }
 
        delete [] out_L;
        out_L = NULL;
 
        delete [] out_R;
        out_R = NULL;
 
        delete[] audioBuffer;
        audioBuffer = NULL;
}
 
 
 

void OssDriver::write()
{
//      infoLog("write");
        unsigned size = oss_driver_bufferSize * 2;
 
        // prepare the 2-channel array of short
        for ( unsigned i = 0; i < ( unsigned )oss_driver_bufferSize; ++i ) {
                audioBuffer[i * 2] = ( short )( out_L[i] * 32768.0 );
                audioBuffer[i * 2 + 1] = ( short )( out_R[i] * 32768.0 );
        }
 
        unsigned long written = ::write( fd, audioBuffer, size * 2 );
 
        if ( written != ( size * 2 ) ) {
                ERRORLOG( "OssDriver: Error writing samples to audio device." );
//              std::cerr << "written = " << written << " of " << (size*2) << endl;
        }
}
 
 
 
 
 
int OssDriver::log2( int n )
{
        int result = 0;
        while ( ( n >>= 1 ) > 0 )
                result++;
        return result;
}
 
 
 
 
unsigned OssDriver::getBufferSize()
{
        return oss_driver_bufferSize;
}
 
 
unsigned OssDriver::getSampleRate()
{
        Preferences *preferencesMng = Preferences::get_instance();
        return preferencesMng->m_nSampleRate;
}
 
 
float* OssDriver::getOut_L()
{
        return out_L;
}
float* OssDriver::getOut_R()
{
        return out_R;
}
};
 
#endif // OSS support