paex_sine_c++.cpp (7935B)
1 /** @file paex_sine.c 2 @ingroup examples_src 3 @brief Play a sine wave for several seconds. 4 @author Ross Bencina <rossb@audiomulch.com> 5 @author Phil Burk <philburk@softsynth.com> 6 */ 7 /* 8 * $Id: paex_sine.c 1752 2011-09-08 03:21:55Z philburk $ 9 * 10 * This program uses the PortAudio Portable Audio Library. 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 #include <stdio.h> 45 #include <math.h> 46 #include "portaudio.h" 47 48 #define NUM_SECONDS (5) 49 #define SAMPLE_RATE (44100) 50 #define FRAMES_PER_BUFFER (64) 51 52 #ifndef M_PI 53 #define M_PI (3.14159265) 54 #endif 55 56 #define TABLE_SIZE (200) 57 58 class Sine 59 { 60 public: 61 Sine() : stream(0), left_phase(0), right_phase(0) 62 { 63 /* initialise sinusoidal wavetable */ 64 for( int i=0; i<TABLE_SIZE; i++ ) 65 { 66 sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ); 67 } 68 69 sprintf( message, "No Message" ); 70 } 71 72 bool open(PaDeviceIndex index) 73 { 74 PaStreamParameters outputParameters; 75 76 outputParameters.device = index; 77 if (outputParameters.device == paNoDevice) { 78 return false; 79 } 80 81 const PaDeviceInfo* pInfo = Pa_GetDeviceInfo(index); 82 if (pInfo != 0) 83 { 84 printf("Output device name: '%s'\r", pInfo->name); 85 } 86 87 outputParameters.channelCount = 2; /* stereo output */ 88 outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */ 89 outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency; 90 outputParameters.hostApiSpecificStreamInfo = NULL; 91 92 PaError err = Pa_OpenStream( 93 &stream, 94 NULL, /* no input */ 95 &outputParameters, 96 SAMPLE_RATE, 97 paFramesPerBufferUnspecified, 98 paClipOff, /* we won't output out of range samples so don't bother clipping them */ 99 &Sine::paCallback, 100 this /* Using 'this' for userData so we can cast to Sine* in paCallback method */ 101 ); 102 103 if (err != paNoError) 104 { 105 /* Failed to open stream to device !!! */ 106 return false; 107 } 108 109 err = Pa_SetStreamFinishedCallback( stream, &Sine::paStreamFinished ); 110 111 if (err != paNoError) 112 { 113 Pa_CloseStream( stream ); 114 stream = 0; 115 116 return false; 117 } 118 119 return true; 120 } 121 122 bool close() 123 { 124 if (stream == 0) 125 return false; 126 127 PaError err = Pa_CloseStream( stream ); 128 stream = 0; 129 130 return (err == paNoError); 131 } 132 133 134 bool start() 135 { 136 if (stream == 0) 137 return false; 138 139 PaError err = Pa_StartStream( stream ); 140 141 return (err == paNoError); 142 } 143 144 bool stop() 145 { 146 if (stream == 0) 147 return false; 148 149 PaError err = Pa_StopStream( stream ); 150 151 return (err == paNoError); 152 } 153 154 private: 155 /* The instance callback, where we have access to every method/variable in object of class Sine */ 156 int paCallbackMethod(const void *inputBuffer, void *outputBuffer, 157 unsigned long framesPerBuffer, 158 const PaStreamCallbackTimeInfo* timeInfo, 159 PaStreamCallbackFlags statusFlags) 160 { 161 float *out = (float*)outputBuffer; 162 unsigned long i; 163 164 (void) timeInfo; /* Prevent unused variable warnings. */ 165 (void) statusFlags; 166 (void) inputBuffer; 167 168 for( i=0; i<framesPerBuffer; i++ ) 169 { 170 *out++ = sine[left_phase]; /* left */ 171 *out++ = sine[right_phase]; /* right */ 172 left_phase += 1; 173 if( left_phase >= TABLE_SIZE ) left_phase -= TABLE_SIZE; 174 right_phase += 3; /* higher pitch so we can distinguish left and right. */ 175 if( right_phase >= TABLE_SIZE ) right_phase -= TABLE_SIZE; 176 } 177 178 return paContinue; 179 180 } 181 182 /* This routine will be called by the PortAudio engine when audio is needed. 183 ** It may called at interrupt level on some machines so don't do anything 184 ** that could mess up the system like calling malloc() or free(). 185 */ 186 static int paCallback( const void *inputBuffer, void *outputBuffer, 187 unsigned long framesPerBuffer, 188 const PaStreamCallbackTimeInfo* timeInfo, 189 PaStreamCallbackFlags statusFlags, 190 void *userData ) 191 { 192 /* Here we cast userData to Sine* type so we can call the instance method paCallbackMethod, we can do that since 193 we called Pa_OpenStream with 'this' for userData */ 194 return ((Sine*)userData)->paCallbackMethod(inputBuffer, outputBuffer, 195 framesPerBuffer, 196 timeInfo, 197 statusFlags); 198 } 199 200 201 void paStreamFinishedMethod() 202 { 203 printf( "Stream Completed: %s\n", message ); 204 } 205 206 /* 207 * This routine is called by portaudio when playback is done. 208 */ 209 static void paStreamFinished(void* userData) 210 { 211 return ((Sine*)userData)->paStreamFinishedMethod(); 212 } 213 214 PaStream *stream; 215 float sine[TABLE_SIZE]; 216 int left_phase; 217 int right_phase; 218 char message[20]; 219 }; 220 221 class ScopedPaHandler 222 { 223 public: 224 ScopedPaHandler() 225 : _result(Pa_Initialize()) 226 { 227 } 228 ~ScopedPaHandler() 229 { 230 if (_result == paNoError) 231 { 232 Pa_Terminate(); 233 } 234 } 235 236 PaError result() const { return _result; } 237 238 private: 239 PaError _result; 240 }; 241 242 243 /*******************************************************************/ 244 int main(void); 245 int main(void) 246 { 247 Sine sine; 248 249 printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER); 250 251 ScopedPaHandler paInit; 252 if( paInit.result() != paNoError ) goto error; 253 254 if (sine.open(Pa_GetDefaultOutputDevice())) 255 { 256 if (sine.start()) 257 { 258 printf("Play for %d seconds.\n", NUM_SECONDS ); 259 Pa_Sleep( NUM_SECONDS * 1000 ); 260 261 sine.stop(); 262 } 263 264 sine.close(); 265 } 266 267 printf("Test finished.\n"); 268 return paNoError; 269 270 error: 271 fprintf( stderr, "An error occured while using the portaudio stream\n" ); 272 fprintf( stderr, "Error number: %d\n", paInit.result() ); 273 fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( paInit.result() ) ); 274 return 1; 275 }