PAAudioOutputStream.cxx

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/*
 * Copyright (c) 2004 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <portaudio.h>
#include "PAAudioOutputStream.hxx"
#include "PortAudioUtils.hxx"
#include "Assert.hxx"

namespace CLAM
{

        void PAAudioOutputStream::SetupStream()
        {
                PaError errval;

        //      CheckConsistency();

                errval = Pa_OpenStream( 
                                                           &mStream,
                                                           paNoDevice,
                                                           0,
                                                           paInt16,
                                                           NULL,
                                                           mConfig.GetDeviceID(),
                                                           mConfig.GetChannelNumber(),
                                                           paInt16,
                                                           NULL,
                                                           mConfig.GetSampleRate(),
                                                           mConfig.GetOutputDblBuffer()->GetSize()/mConfig.GetChannelNumber(),
                                                           0,
                                                           0,
                                                           mConfig.GetCallback(),
                                                           mConfig.GetOutputDblBuffer() );

                CHECK_PA_ERROR( "Error opening the stream: ", errval );
        }

        void PAAudioOutputStream::CheckConsistency()
        {
                const PaDeviceInfo* devnfo = Pa_GetDeviceInfo( mConfig.GetDeviceID() );
                
                if ( devnfo == NULL )
                        throw ErrPortAudio("Error opening stream\nThe device id is not valid");

                // MRJ: Let's check if the capabilities of the selected
                // device meet the requirements expressed in the stream
                // configuration object

                // I don't like much this but I don't see clearly the
                // utility of using CLAM_ASSERT's beyond saving me
                // of typing the conditionals...

                // Check number of channels
                if ( mConfig.GetChannelNumber() > devnfo->maxOutputChannels )
                        throw ErrPortAudio("Error opening the stream:\nNumber of output channels requested is not supported by the device\n" );

                // Check the sample rate. Let's determine wether
                // the requested sample rate is supported

                unsigned supportedSr;
                bool isSupported = false;

                for ( int k = devnfo->numSampleRates - 1; k >= 0; k-- )
                        {
                                supportedSr = (unsigned)devnfo->sampleRates[k];
                                if ( mConfig.GetSampleRate() == supportedSr )
                                        isSupported = true;
                        }

                // Requested sample rate is not supported
                if ( !isSupported ) 
                        throw ErrPortAudio( "Error opening the stream:\nRequested Sample rate not supported by the device" );

                // These ones are asserts
                CLAM_ASSERT( mConfig.GetDblBuffer()!=NULL, "The double buffer for the stream cannot be nil!" );
                CLAM_ASSERT( mConfig.GetCallback()!=NULL, "The callback for the stream is nil!" );
        }

}

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