109 lines
3.8 KiB
C
109 lines
3.8 KiB
C
/*
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* $Id: test_w_saw.c,v 1.3 2006/06/10 21:30:55 dmazzoni Exp $
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* test_w_saw.c
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* Generate stereo sawtooth waveforms.
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*
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* Author: Phil Burk, http://www.softsynth.com
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*
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* This program uses PABLIO, the Portable Audio Blocking I/O Library.
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* PABLIO is built on top of PortAudio, the Portable Audio Library.
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*
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* For more information see: http://www.audiomulch.com/portaudio/
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* Copyright (c) 1999-2000 Ross Bencina and Phil Burk
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files
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* (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* Any person wishing to distribute modifications to the Software is
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* requested to send the modifications to the original developer so that
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* they can be incorporated into the canonical version.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
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* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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#include "pablio.h"
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#include <string.h>
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#define SAMPLE_RATE (44100)
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#define NUM_SECONDS (6)
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#define SAMPLES_PER_FRAME (2)
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#define FREQUENCY (220.0f)
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#define PHASE_INCREMENT (2.0f * FREQUENCY / SAMPLE_RATE)
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#define FRAMES_PER_BLOCK (100)
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float samples[FRAMES_PER_BLOCK][SAMPLES_PER_FRAME];
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float phases[SAMPLES_PER_FRAME];
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/*******************************************************************/
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int main(void);
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int main(void)
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{
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int i,j;
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PaError err;
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PABLIO_Stream *aOutStream;
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printf("Generate sawtooth waves using PABLIO.\n");
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fflush(stdout);
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/* Open simplified blocking I/O layer on top of PortAudio. */
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err = OpenAudioStream( &aOutStream, SAMPLE_RATE, paFloat32,
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(PABLIO_WRITE | PABLIO_STEREO) );
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if( err != paNoError ) goto error;
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/* Initialize oscillator phases. */
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phases[0] = 0.0;
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phases[1] = 0.0;
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for( i=0; i<(NUM_SECONDS * SAMPLE_RATE); i += FRAMES_PER_BLOCK )
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{
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/* Generate sawtooth waveforms in a block for efficiency. */
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for( j=0; j<FRAMES_PER_BLOCK; j++ )
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{
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/* Generate a sawtooth wave by incrementing a variable. */
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phases[0] += PHASE_INCREMENT;
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/* The signal range is -1.0 to +1.0 so wrap around if we go over. */
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if( phases[0] > 1.0f ) phases[0] -= 2.0f;
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samples[j][0] = phases[0];
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/* On the second channel, generate a sawtooth wave a fifth higher. */
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phases[1] += PHASE_INCREMENT * (3.0f / 2.0f);
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if( phases[1] > 1.0f ) phases[1] -= 2.0f;
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samples[j][1] = phases[1];
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}
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/* Write samples to output. */
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WriteAudioStream( aOutStream, samples, FRAMES_PER_BLOCK );
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}
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CloseAudioStream( aOutStream );
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printf("Sawtooth sound test complete.\n" );
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fflush(stdout);
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return 0;
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error:
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fprintf( stderr, "An error occured while using PABLIO\n" );
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fprintf( stderr, "Error number: %d\n", err );
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fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
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return -1;
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}
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