test_w_saw.c (4084B)
1 /* 2 * $Id$ 3 * test_w_saw.c 4 * Generate stereo sawtooth waveforms. 5 * 6 * Author: Phil Burk, http://www.softsynth.com 7 * 8 * This program uses PABLIO, the Portable Audio Blocking I/O Library. 9 * PABLIO is built on top of PortAudio, the Portable Audio Library. 10 * 11 * For more information see: http://www.portaudio.com 12 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk 13 * 14 * Permission is hereby granted, free of charge, to any person obtaining 15 * a copy of this software and associated documentation files 16 * (the "Software"), to deal in the Software without restriction, 17 * including without limitation the rights to use, copy, modify, merge, 18 * publish, distribute, sublicense, and/or sell copies of the Software, 19 * and to permit persons to whom the Software is furnished to do so, 20 * subject to the following conditions: 21 * 22 * The above copyright notice and this permission notice shall be 23 * included in all copies or substantial portions of the Software. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 28 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 29 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 30 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 31 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 32 */ 33 34 /* 35 * The text above constitutes the entire PortAudio license; however, 36 * the PortAudio community also makes the following non-binding requests: 37 * 38 * Any person wishing to distribute modifications to the Software is 39 * requested to send the modifications to the original developer so that 40 * they can be incorporated into the canonical version. It is also 41 * requested that these non-binding requests be included along with the 42 * license above. 43 */ 44 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <math.h> 48 #include "pablio.h" 49 #include <string.h> 50 51 #define SAMPLE_RATE (44100) 52 #define NUM_SECONDS (6) 53 #define SAMPLES_PER_FRAME (2) 54 55 #define FREQUENCY (220.0f) 56 #define PHASE_INCREMENT (2.0f * FREQUENCY / SAMPLE_RATE) 57 #define FRAMES_PER_BLOCK (100) 58 59 float samples[FRAMES_PER_BLOCK][SAMPLES_PER_FRAME]; 60 float phases[SAMPLES_PER_FRAME]; 61 62 /*******************************************************************/ 63 int main(void); 64 int main(void) 65 { 66 int i,j; 67 PaError err; 68 PABLIO_Stream *aOutStream; 69 70 printf("Generate sawtooth waves using PABLIO.\n"); 71 fflush(stdout); 72 73 /* Open simplified blocking I/O layer on top of PortAudio. */ 74 err = OpenAudioStream( &aOutStream, SAMPLE_RATE, paFloat32, 75 (PABLIO_WRITE | PABLIO_STEREO) ); 76 if( err != paNoError ) goto error; 77 78 /* Initialize oscillator phases. */ 79 phases[0] = 0.0; 80 phases[1] = 0.0; 81 82 for( i=0; i<(NUM_SECONDS * SAMPLE_RATE); i += FRAMES_PER_BLOCK ) 83 { 84 /* Generate sawtooth waveforms in a block for efficiency. */ 85 for( j=0; j<FRAMES_PER_BLOCK; j++ ) 86 { 87 /* Generate a sawtooth wave by incrementing a variable. */ 88 phases[0] += PHASE_INCREMENT; 89 /* The signal range is -1.0 to +1.0 so wrap around if we go over. */ 90 if( phases[0] > 1.0f ) phases[0] -= 2.0f; 91 samples[j][0] = phases[0]; 92 93 /* On the second channel, generate a sawtooth wave a fifth higher. */ 94 phases[1] += PHASE_INCREMENT * (3.0f / 2.0f); 95 if( phases[1] > 1.0f ) phases[1] -= 2.0f; 96 samples[j][1] = phases[1]; 97 } 98 99 /* Write samples to output. */ 100 WriteAudioStream( aOutStream, samples, FRAMES_PER_BLOCK ); 101 } 102 103 CloseAudioStream( aOutStream ); 104 105 printf("Sawtooth sound test complete.\n" ); 106 fflush(stdout); 107 return 0; 108 109 error: 110 fprintf( stderr, "An error occured while using PABLIO\n" ); 111 fprintf( stderr, "Error number: %d\n", err ); 112 fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); 113 return -1; 114 }