cannam@162: /** @file paex_saw.c cannam@162: @ingroup examples_src cannam@162: @brief Play a simple (aliasing) sawtooth wave. cannam@162: @author Phil Burk http://www.softsynth.com cannam@162: */ cannam@162: /* cannam@162: * $Id$ cannam@162: * cannam@162: * This program uses the PortAudio Portable Audio Library. cannam@162: * For more information see: http://www.portaudio.com cannam@162: * Copyright (c) 1999-2000 Ross Bencina and Phil Burk cannam@162: * cannam@162: * Permission is hereby granted, free of charge, to any person obtaining cannam@162: * a copy of this software and associated documentation files cannam@162: * (the "Software"), to deal in the Software without restriction, cannam@162: * including without limitation the rights to use, copy, modify, merge, cannam@162: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@162: * and to permit persons to whom the Software is furnished to do so, cannam@162: * subject to the following conditions: cannam@162: * cannam@162: * The above copyright notice and this permission notice shall be cannam@162: * included in all copies or substantial portions of the Software. cannam@162: * cannam@162: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@162: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@162: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@162: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@162: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@162: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@162: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@162: */ cannam@162: cannam@162: /* cannam@162: * The text above constitutes the entire PortAudio license; however, cannam@162: * the PortAudio community also makes the following non-binding requests: cannam@162: * cannam@162: * Any person wishing to distribute modifications to the Software is cannam@162: * requested to send the modifications to the original developer so that cannam@162: * they can be incorporated into the canonical version. It is also cannam@162: * requested that these non-binding requests be included along with the cannam@162: * license above. cannam@162: */ cannam@162: cannam@162: #include cannam@162: #include cannam@162: #include "portaudio.h" cannam@162: #define NUM_SECONDS (4) cannam@162: #define SAMPLE_RATE (44100) cannam@162: cannam@162: typedef struct cannam@162: { cannam@162: float left_phase; cannam@162: float right_phase; cannam@162: } cannam@162: paTestData; cannam@162: cannam@162: /* This routine will be called by the PortAudio engine when audio is needed. cannam@162: ** It may called at interrupt level on some machines so don't do anything cannam@162: ** that could mess up the system like calling malloc() or free(). cannam@162: */ cannam@162: static int patestCallback( const void *inputBuffer, void *outputBuffer, cannam@162: unsigned long framesPerBuffer, cannam@162: const PaStreamCallbackTimeInfo* timeInfo, cannam@162: PaStreamCallbackFlags statusFlags, cannam@162: void *userData ) cannam@162: { cannam@162: /* Cast data passed through stream to our structure. */ cannam@162: paTestData *data = (paTestData*)userData; cannam@162: float *out = (float*)outputBuffer; cannam@162: unsigned int i; cannam@162: (void) inputBuffer; /* Prevent unused variable warning. */ cannam@162: cannam@162: for( i=0; ileft_phase; /* left */ cannam@162: *out++ = data->right_phase; /* right */ cannam@162: /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ cannam@162: data->left_phase += 0.01f; cannam@162: /* When signal reaches top, drop back down. */ cannam@162: if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; cannam@162: /* higher pitch so we can distinguish left and right. */ cannam@162: data->right_phase += 0.03f; cannam@162: if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; cannam@162: } cannam@162: return 0; cannam@162: } cannam@162: cannam@162: /*******************************************************************/ cannam@162: static paTestData data; cannam@162: int main(void); cannam@162: int main(void) cannam@162: { cannam@162: PaStream *stream; cannam@162: PaError err; cannam@162: cannam@162: printf("PortAudio Test: output sawtooth wave.\n"); cannam@162: /* Initialize our data for use by callback. */ cannam@162: data.left_phase = data.right_phase = 0.0; cannam@162: /* Initialize library before making any other calls. */ cannam@162: err = Pa_Initialize(); cannam@162: if( err != paNoError ) goto error; cannam@162: cannam@162: /* Open an audio I/O stream. */ cannam@162: err = Pa_OpenDefaultStream( &stream, cannam@162: 0, /* no input channels */ cannam@162: 2, /* stereo output */ cannam@162: paFloat32, /* 32 bit floating point output */ cannam@162: SAMPLE_RATE, cannam@162: 256, /* frames per buffer */ cannam@162: patestCallback, cannam@162: &data ); cannam@162: if( err != paNoError ) goto error; cannam@162: cannam@162: err = Pa_StartStream( stream ); cannam@162: if( err != paNoError ) goto error; cannam@162: cannam@162: /* Sleep for several seconds. */ cannam@162: Pa_Sleep(NUM_SECONDS*1000); cannam@162: cannam@162: err = Pa_StopStream( stream ); cannam@162: if( err != paNoError ) goto error; cannam@162: err = Pa_CloseStream( stream ); cannam@162: if( err != paNoError ) goto error; cannam@162: Pa_Terminate(); cannam@162: printf("Test finished.\n"); cannam@162: return err; cannam@162: error: cannam@162: Pa_Terminate(); cannam@162: fprintf( stderr, "An error occured while using the portaudio stream\n" ); cannam@162: fprintf( stderr, "Error number: %d\n", err ); cannam@162: fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); cannam@162: return err; cannam@162: }