Chris@4: /** @file paex_saw.c Chris@4: @ingroup examples_src Chris@4: @brief Play a simple (aliasing) sawtooth wave. Chris@4: @author Phil Burk http://www.softsynth.com Chris@4: */ Chris@4: /* Chris@4: * $Id: paex_saw.c 1752 2011-09-08 03:21:55Z philburk $ Chris@4: * Chris@4: * This program uses the PortAudio Portable Audio Library. Chris@4: * For more information see: http://www.portaudio.com Chris@4: * Copyright (c) 1999-2000 Ross Bencina and Phil Burk Chris@4: * Chris@4: * Permission is hereby granted, free of charge, to any person obtaining Chris@4: * a copy of this software and associated documentation files Chris@4: * (the "Software"), to deal in the Software without restriction, Chris@4: * including without limitation the rights to use, copy, modify, merge, Chris@4: * publish, distribute, sublicense, and/or sell copies of the Software, Chris@4: * and to permit persons to whom the Software is furnished to do so, Chris@4: * subject to the following conditions: Chris@4: * Chris@4: * The above copyright notice and this permission notice shall be Chris@4: * included in all copies or substantial portions of the Software. Chris@4: * Chris@4: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, Chris@4: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF Chris@4: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. Chris@4: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR Chris@4: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF Chris@4: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION Chris@4: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Chris@4: */ Chris@4: Chris@4: /* Chris@4: * The text above constitutes the entire PortAudio license; however, Chris@4: * the PortAudio community also makes the following non-binding requests: Chris@4: * Chris@4: * Any person wishing to distribute modifications to the Software is Chris@4: * requested to send the modifications to the original developer so that Chris@4: * they can be incorporated into the canonical version. It is also Chris@4: * requested that these non-binding requests be included along with the Chris@4: * license above. Chris@4: */ Chris@4: Chris@4: #include Chris@4: #include Chris@4: #include "portaudio.h" Chris@4: #define NUM_SECONDS (4) Chris@4: #define SAMPLE_RATE (44100) Chris@4: Chris@4: typedef struct Chris@4: { Chris@4: float left_phase; Chris@4: float right_phase; Chris@4: } Chris@4: paTestData; Chris@4: Chris@4: /* This routine will be called by the PortAudio engine when audio is needed. Chris@4: ** It may called at interrupt level on some machines so don't do anything Chris@4: ** that could mess up the system like calling malloc() or free(). Chris@4: */ Chris@4: static int patestCallback( const void *inputBuffer, void *outputBuffer, Chris@4: unsigned long framesPerBuffer, Chris@4: const PaStreamCallbackTimeInfo* timeInfo, Chris@4: PaStreamCallbackFlags statusFlags, Chris@4: void *userData ) Chris@4: { Chris@4: /* Cast data passed through stream to our structure. */ Chris@4: paTestData *data = (paTestData*)userData; Chris@4: float *out = (float*)outputBuffer; Chris@4: unsigned int i; Chris@4: (void) inputBuffer; /* Prevent unused variable warning. */ Chris@4: Chris@4: for( i=0; ileft_phase; /* left */ Chris@4: *out++ = data->right_phase; /* right */ Chris@4: /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ Chris@4: data->left_phase += 0.01f; Chris@4: /* When signal reaches top, drop back down. */ Chris@4: if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; Chris@4: /* higher pitch so we can distinguish left and right. */ Chris@4: data->right_phase += 0.03f; Chris@4: if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; Chris@4: } Chris@4: return 0; Chris@4: } Chris@4: Chris@4: /*******************************************************************/ Chris@4: static paTestData data; Chris@4: int main(void); Chris@4: int main(void) Chris@4: { Chris@4: PaStream *stream; Chris@4: PaError err; Chris@4: Chris@4: printf("PortAudio Test: output sawtooth wave.\n"); Chris@4: /* Initialize our data for use by callback. */ Chris@4: data.left_phase = data.right_phase = 0.0; Chris@4: /* Initialize library before making any other calls. */ Chris@4: err = Pa_Initialize(); Chris@4: if( err != paNoError ) goto error; Chris@4: Chris@4: /* Open an audio I/O stream. */ Chris@4: err = Pa_OpenDefaultStream( &stream, Chris@4: 0, /* no input channels */ Chris@4: 2, /* stereo output */ Chris@4: paFloat32, /* 32 bit floating point output */ Chris@4: SAMPLE_RATE, Chris@4: 256, /* frames per buffer */ Chris@4: patestCallback, Chris@4: &data ); Chris@4: if( err != paNoError ) goto error; Chris@4: Chris@4: err = Pa_StartStream( stream ); Chris@4: if( err != paNoError ) goto error; Chris@4: Chris@4: /* Sleep for several seconds. */ Chris@4: Pa_Sleep(NUM_SECONDS*1000); Chris@4: Chris@4: err = Pa_StopStream( stream ); Chris@4: if( err != paNoError ) goto error; Chris@4: err = Pa_CloseStream( stream ); Chris@4: if( err != paNoError ) goto error; Chris@4: Pa_Terminate(); Chris@4: printf("Test finished.\n"); Chris@4: return err; Chris@4: error: Chris@4: Pa_Terminate(); Chris@4: fprintf( stderr, "An error occured while using the portaudio stream\n" ); Chris@4: fprintf( stderr, "Error number: %d\n", err ); Chris@4: fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); Chris@4: return err; Chris@4: }