cannam@140: /** @file paex_saw.c cannam@140: @ingroup examples_src cannam@140: @brief Play a simple (aliasing) sawtooth wave. cannam@140: @author Phil Burk http://www.softsynth.com cannam@140: */ cannam@140: /* cannam@140: * $Id$ cannam@140: * cannam@140: * This program uses the PortAudio Portable Audio Library. cannam@140: * For more information see: http://www.portaudio.com cannam@140: * Copyright (c) 1999-2000 Ross Bencina and Phil Burk cannam@140: * cannam@140: * Permission is hereby granted, free of charge, to any person obtaining cannam@140: * a copy of this software and associated documentation files cannam@140: * (the "Software"), to deal in the Software without restriction, cannam@140: * including without limitation the rights to use, copy, modify, merge, cannam@140: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@140: * and to permit persons to whom the Software is furnished to do so, cannam@140: * subject to the following conditions: cannam@140: * cannam@140: * The above copyright notice and this permission notice shall be cannam@140: * included in all copies or substantial portions of the Software. cannam@140: * cannam@140: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@140: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@140: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@140: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@140: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@140: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@140: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@140: */ cannam@140: cannam@140: /* cannam@140: * The text above constitutes the entire PortAudio license; however, cannam@140: * the PortAudio community also makes the following non-binding requests: cannam@140: * cannam@140: * Any person wishing to distribute modifications to the Software is cannam@140: * requested to send the modifications to the original developer so that cannam@140: * they can be incorporated into the canonical version. It is also cannam@140: * requested that these non-binding requests be included along with the cannam@140: * license above. cannam@140: */ cannam@140: cannam@140: #include cannam@140: #include cannam@140: #include "portaudio.h" cannam@140: #define NUM_SECONDS (4) cannam@140: #define SAMPLE_RATE (44100) cannam@140: cannam@140: typedef struct cannam@140: { cannam@140: float left_phase; cannam@140: float right_phase; cannam@140: } cannam@140: paTestData; cannam@140: cannam@140: /* This routine will be called by the PortAudio engine when audio is needed. cannam@140: ** It may called at interrupt level on some machines so don't do anything cannam@140: ** that could mess up the system like calling malloc() or free(). cannam@140: */ cannam@140: static int patestCallback( const void *inputBuffer, void *outputBuffer, cannam@140: unsigned long framesPerBuffer, cannam@140: const PaStreamCallbackTimeInfo* timeInfo, cannam@140: PaStreamCallbackFlags statusFlags, cannam@140: void *userData ) cannam@140: { cannam@140: /* Cast data passed through stream to our structure. */ cannam@140: paTestData *data = (paTestData*)userData; cannam@140: float *out = (float*)outputBuffer; cannam@140: unsigned int i; cannam@140: (void) inputBuffer; /* Prevent unused variable warning. */ cannam@140: cannam@140: for( i=0; ileft_phase; /* left */ cannam@140: *out++ = data->right_phase; /* right */ cannam@140: /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ cannam@140: data->left_phase += 0.01f; cannam@140: /* When signal reaches top, drop back down. */ cannam@140: if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; cannam@140: /* higher pitch so we can distinguish left and right. */ cannam@140: data->right_phase += 0.03f; cannam@140: if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; cannam@140: } cannam@140: return 0; cannam@140: } cannam@140: cannam@140: /*******************************************************************/ cannam@140: static paTestData data; cannam@140: int main(void); cannam@140: int main(void) cannam@140: { cannam@140: PaStream *stream; cannam@140: PaError err; cannam@140: cannam@140: printf("PortAudio Test: output sawtooth wave.\n"); cannam@140: /* Initialize our data for use by callback. */ cannam@140: data.left_phase = data.right_phase = 0.0; cannam@140: /* Initialize library before making any other calls. */ cannam@140: err = Pa_Initialize(); cannam@140: if( err != paNoError ) goto error; cannam@140: cannam@140: /* Open an audio I/O stream. */ cannam@140: err = Pa_OpenDefaultStream( &stream, cannam@140: 0, /* no input channels */ cannam@140: 2, /* stereo output */ cannam@140: paFloat32, /* 32 bit floating point output */ cannam@140: SAMPLE_RATE, cannam@140: 256, /* frames per buffer */ cannam@140: patestCallback, cannam@140: &data ); cannam@140: if( err != paNoError ) goto error; cannam@140: cannam@140: err = Pa_StartStream( stream ); cannam@140: if( err != paNoError ) goto error; cannam@140: cannam@140: /* Sleep for several seconds. */ cannam@140: Pa_Sleep(NUM_SECONDS*1000); cannam@140: cannam@140: err = Pa_StopStream( stream ); cannam@140: if( err != paNoError ) goto error; cannam@140: err = Pa_CloseStream( stream ); cannam@140: if( err != paNoError ) goto error; cannam@140: Pa_Terminate(); cannam@140: printf("Test finished.\n"); cannam@140: return err; cannam@140: error: cannam@140: Pa_Terminate(); cannam@140: fprintf( stderr, "An error occured while using the portaudio stream\n" ); cannam@140: fprintf( stderr, "Error number: %d\n", err ); cannam@140: fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); cannam@140: return err; cannam@140: }