/* * $Id: patest_clip.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger Exp $ * patest_clip.c * Play a sine wave using the Portable Audio api for several seconds * at an amplitude that would require clipping. * * Author: Phil Burk http://www.softsynth.com * * This program uses the PortAudio Portable Audio Library. * For more information see: http://www.portaudio.com * Copyright (c) 1999-2000 Ross Bencina and Phil Burk * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * Any person wishing to distribute modifications to the Software is * requested to send the modifications to the original developer so that * they can be incorporated into the canonical version. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * */ #include #include #include "portaudio.h" #define NUM_SECONDS (4) #define SAMPLE_RATE (44100) #ifndef M_PI #define M_PI (3.14159265) #endif #define TABLE_SIZE (200) typedef struct paTestData { float sine[TABLE_SIZE]; float amplitude; int left_phase; int right_phase; } paTestData; PaError PlaySine( paTestData *data, unsigned long flags, float amplitude ); /* This routine will be called by the PortAudio engine when audio is needed. ** It may called at interrupt level on some machines so don't do anything ** that could mess up the system like calling malloc() or free(). */ static int sineCallback( void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, PaTimestamp outTime, void *userData ) { paTestData *data = (paTestData*)userData; float *out = (float*)outputBuffer; float amplitude = data->amplitude; unsigned int i; (void) inputBuffer; /* Prevent "unused variable" warnings. */ (void) outTime; for( i=0; isine[data->left_phase]; /* left */ *out++ = amplitude * data->sine[data->right_phase]; /* right */ data->left_phase += 1; if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE; data->right_phase += 3; /* higher pitch so we can distinguish left and right. */ if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE; } return 0; } /*******************************************************************/ int main(void); int main(void) { PaError err; paTestData DATA; int i; printf("PortAudio Test: output sine wave with and without clipping.\n"); /* initialise sinusoidal wavetable */ for( i=0; ileft_phase = data->right_phase = 0; data->amplitude = amplitude; err = Pa_Initialize(); if( err != paNoError ) goto error; err = Pa_OpenStream( &stream, paNoDevice,/* default input device */ 0, /* no input */ paFloat32, /* 32 bit floating point input */ NULL, Pa_GetDefaultOutputDeviceID(), /* default output device */ 2, /* stereo output */ paFloat32, /* 32 bit floating point output */ NULL, SAMPLE_RATE, 1024, 0, /* number of buffers, if zero then use default minimum */ flags, /* we won't output out of range samples so don't bother clipping them */ sineCallback, data ); if( err != paNoError ) goto error; err = Pa_StartStream( stream ); if( err != paNoError ) goto error; Pa_Sleep( NUM_SECONDS * 1000 ); printf("CPULoad = %8.6f\n", Pa_GetCPULoad( stream ) ); err = Pa_CloseStream( stream ); if( err != paNoError ) goto error; Pa_Terminate(); return paNoError; error: return err; }