cannam@124: /** @file paex_saw.c cannam@124: @ingroup examples_src cannam@124: @brief Play a simple (aliasing) sawtooth wave. cannam@124: @author Phil Burk http://www.softsynth.com cannam@124: */ cannam@124: /* cannam@124: * $Id: paex_saw.c 1752 2011-09-08 03:21:55Z philburk $ cannam@124: * cannam@124: * This program uses the PortAudio Portable Audio Library. cannam@124: * For more information see: http://www.portaudio.com cannam@124: * Copyright (c) 1999-2000 Ross Bencina and Phil Burk cannam@124: * cannam@124: * Permission is hereby granted, free of charge, to any person obtaining cannam@124: * a copy of this software and associated documentation files cannam@124: * (the "Software"), to deal in the Software without restriction, cannam@124: * including without limitation the rights to use, copy, modify, merge, cannam@124: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@124: * and to permit persons to whom the Software is furnished to do so, cannam@124: * subject to the following conditions: cannam@124: * cannam@124: * The above copyright notice and this permission notice shall be cannam@124: * included in all copies or substantial portions of the Software. cannam@124: * cannam@124: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@124: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@124: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@124: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@124: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@124: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@124: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@124: */ cannam@124: cannam@124: /* cannam@124: * The text above constitutes the entire PortAudio license; however, cannam@124: * the PortAudio community also makes the following non-binding requests: cannam@124: * cannam@124: * Any person wishing to distribute modifications to the Software is cannam@124: * requested to send the modifications to the original developer so that cannam@124: * they can be incorporated into the canonical version. It is also cannam@124: * requested that these non-binding requests be included along with the cannam@124: * license above. cannam@124: */ cannam@124: cannam@124: #include cannam@124: #include cannam@124: #include "portaudio.h" cannam@124: #define NUM_SECONDS (4) cannam@124: #define SAMPLE_RATE (44100) cannam@124: cannam@124: typedef struct cannam@124: { cannam@124: float left_phase; cannam@124: float right_phase; cannam@124: } cannam@124: paTestData; cannam@124: cannam@124: /* This routine will be called by the PortAudio engine when audio is needed. cannam@124: ** It may called at interrupt level on some machines so don't do anything cannam@124: ** that could mess up the system like calling malloc() or free(). cannam@124: */ cannam@124: static int patestCallback( const void *inputBuffer, void *outputBuffer, cannam@124: unsigned long framesPerBuffer, cannam@124: const PaStreamCallbackTimeInfo* timeInfo, cannam@124: PaStreamCallbackFlags statusFlags, cannam@124: void *userData ) cannam@124: { cannam@124: /* Cast data passed through stream to our structure. */ cannam@124: paTestData *data = (paTestData*)userData; cannam@124: float *out = (float*)outputBuffer; cannam@124: unsigned int i; cannam@124: (void) inputBuffer; /* Prevent unused variable warning. */ cannam@124: cannam@124: for( i=0; ileft_phase; /* left */ cannam@124: *out++ = data->right_phase; /* right */ cannam@124: /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ cannam@124: data->left_phase += 0.01f; cannam@124: /* When signal reaches top, drop back down. */ cannam@124: if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; cannam@124: /* higher pitch so we can distinguish left and right. */ cannam@124: data->right_phase += 0.03f; cannam@124: if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; cannam@124: } cannam@124: return 0; cannam@124: } cannam@124: cannam@124: /*******************************************************************/ cannam@124: static paTestData data; cannam@124: int main(void); cannam@124: int main(void) cannam@124: { cannam@124: PaStream *stream; cannam@124: PaError err; cannam@124: cannam@124: printf("PortAudio Test: output sawtooth wave.\n"); cannam@124: /* Initialize our data for use by callback. */ cannam@124: data.left_phase = data.right_phase = 0.0; cannam@124: /* Initialize library before making any other calls. */ cannam@124: err = Pa_Initialize(); cannam@124: if( err != paNoError ) goto error; cannam@124: cannam@124: /* Open an audio I/O stream. */ cannam@124: err = Pa_OpenDefaultStream( &stream, cannam@124: 0, /* no input channels */ cannam@124: 2, /* stereo output */ cannam@124: paFloat32, /* 32 bit floating point output */ cannam@124: SAMPLE_RATE, cannam@124: 256, /* frames per buffer */ cannam@124: patestCallback, cannam@124: &data ); cannam@124: if( err != paNoError ) goto error; cannam@124: cannam@124: err = Pa_StartStream( stream ); cannam@124: if( err != paNoError ) goto error; cannam@124: cannam@124: /* Sleep for several seconds. */ cannam@124: Pa_Sleep(NUM_SECONDS*1000); cannam@124: cannam@124: err = Pa_StopStream( stream ); cannam@124: if( err != paNoError ) goto error; cannam@124: err = Pa_CloseStream( stream ); cannam@124: if( err != paNoError ) goto error; cannam@124: Pa_Terminate(); cannam@124: printf("Test finished.\n"); cannam@124: return err; cannam@124: error: cannam@124: Pa_Terminate(); cannam@124: fprintf( stderr, "An error occured while using the portaudio stream\n" ); cannam@124: fprintf( stderr, "Error number: %d\n", err ); cannam@124: fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); cannam@124: return err; cannam@124: }