cannam@89: /** @file paex_saw.c cannam@89: @ingroup examples_src cannam@89: @brief Play a simple (aliasing) sawtooth wave. cannam@89: @author Phil Burk http://www.softsynth.com cannam@89: */ cannam@89: /* cannam@89: * $Id: paex_saw.c 1752 2011-09-08 03:21:55Z philburk $ cannam@89: * cannam@89: * This program uses the PortAudio Portable Audio Library. cannam@89: * For more information see: http://www.portaudio.com cannam@89: * Copyright (c) 1999-2000 Ross Bencina and Phil Burk cannam@89: * cannam@89: * Permission is hereby granted, free of charge, to any person obtaining cannam@89: * a copy of this software and associated documentation files cannam@89: * (the "Software"), to deal in the Software without restriction, cannam@89: * including without limitation the rights to use, copy, modify, merge, cannam@89: * publish, distribute, sublicense, and/or sell copies of the Software, cannam@89: * and to permit persons to whom the Software is furnished to do so, cannam@89: * subject to the following conditions: cannam@89: * cannam@89: * The above copyright notice and this permission notice shall be cannam@89: * included in all copies or substantial portions of the Software. cannam@89: * cannam@89: * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, cannam@89: * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF cannam@89: * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. cannam@89: * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR cannam@89: * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF cannam@89: * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION cannam@89: * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. cannam@89: */ cannam@89: cannam@89: /* cannam@89: * The text above constitutes the entire PortAudio license; however, cannam@89: * the PortAudio community also makes the following non-binding requests: cannam@89: * cannam@89: * Any person wishing to distribute modifications to the Software is cannam@89: * requested to send the modifications to the original developer so that cannam@89: * they can be incorporated into the canonical version. It is also cannam@89: * requested that these non-binding requests be included along with the cannam@89: * license above. cannam@89: */ cannam@89: cannam@89: #include cannam@89: #include cannam@89: #include "portaudio.h" cannam@89: #define NUM_SECONDS (4) cannam@89: #define SAMPLE_RATE (44100) cannam@89: cannam@89: typedef struct cannam@89: { cannam@89: float left_phase; cannam@89: float right_phase; cannam@89: } cannam@89: paTestData; cannam@89: cannam@89: /* This routine will be called by the PortAudio engine when audio is needed. cannam@89: ** It may called at interrupt level on some machines so don't do anything cannam@89: ** that could mess up the system like calling malloc() or free(). cannam@89: */ cannam@89: static int patestCallback( const void *inputBuffer, void *outputBuffer, cannam@89: unsigned long framesPerBuffer, cannam@89: const PaStreamCallbackTimeInfo* timeInfo, cannam@89: PaStreamCallbackFlags statusFlags, cannam@89: void *userData ) cannam@89: { cannam@89: /* Cast data passed through stream to our structure. */ cannam@89: paTestData *data = (paTestData*)userData; cannam@89: float *out = (float*)outputBuffer; cannam@89: unsigned int i; cannam@89: (void) inputBuffer; /* Prevent unused variable warning. */ cannam@89: cannam@89: for( i=0; ileft_phase; /* left */ cannam@89: *out++ = data->right_phase; /* right */ cannam@89: /* Generate simple sawtooth phaser that ranges between -1.0 and 1.0. */ cannam@89: data->left_phase += 0.01f; cannam@89: /* When signal reaches top, drop back down. */ cannam@89: if( data->left_phase >= 1.0f ) data->left_phase -= 2.0f; cannam@89: /* higher pitch so we can distinguish left and right. */ cannam@89: data->right_phase += 0.03f; cannam@89: if( data->right_phase >= 1.0f ) data->right_phase -= 2.0f; cannam@89: } cannam@89: return 0; cannam@89: } cannam@89: cannam@89: /*******************************************************************/ cannam@89: static paTestData data; cannam@89: int main(void); cannam@89: int main(void) cannam@89: { cannam@89: PaStream *stream; cannam@89: PaError err; cannam@89: cannam@89: printf("PortAudio Test: output sawtooth wave.\n"); cannam@89: /* Initialize our data for use by callback. */ cannam@89: data.left_phase = data.right_phase = 0.0; cannam@89: /* Initialize library before making any other calls. */ cannam@89: err = Pa_Initialize(); cannam@89: if( err != paNoError ) goto error; cannam@89: cannam@89: /* Open an audio I/O stream. */ cannam@89: err = Pa_OpenDefaultStream( &stream, cannam@89: 0, /* no input channels */ cannam@89: 2, /* stereo output */ cannam@89: paFloat32, /* 32 bit floating point output */ cannam@89: SAMPLE_RATE, cannam@89: 256, /* frames per buffer */ cannam@89: patestCallback, cannam@89: &data ); cannam@89: if( err != paNoError ) goto error; cannam@89: cannam@89: err = Pa_StartStream( stream ); cannam@89: if( err != paNoError ) goto error; cannam@89: cannam@89: /* Sleep for several seconds. */ cannam@89: Pa_Sleep(NUM_SECONDS*1000); cannam@89: cannam@89: err = Pa_StopStream( stream ); cannam@89: if( err != paNoError ) goto error; cannam@89: err = Pa_CloseStream( stream ); cannam@89: if( err != paNoError ) goto error; cannam@89: Pa_Terminate(); cannam@89: printf("Test finished.\n"); cannam@89: return err; cannam@89: error: cannam@89: Pa_Terminate(); cannam@89: fprintf( stderr, "An error occured while using the portaudio stream\n" ); cannam@89: fprintf( stderr, "Error number: %d\n", err ); cannam@89: fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); cannam@89: return err; cannam@89: }