PortAudio  2.0
paex_sine_c++.cpp
1 
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  outputParameters.channelCount = 2; /* stereo output */
82  outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
83  outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
84  outputParameters.hostApiSpecificStreamInfo = NULL;
85 
86  PaError err = Pa_OpenStream(
87  &stream,
88  NULL, /* no input */
89  &outputParameters,
90  SAMPLE_RATE,
91  FRAMES_PER_BUFFER,
92  paClipOff, /* we won't output out of range samples so don't bother clipping them */
93  &Sine::paCallback,
94  this /* Using 'this' for userData so we can cast to Sine* in paCallback method */
95  );
96 
97  if (err != paNoError)
98  {
99  /* Failed to open stream to device !!! */
100  return false;
101  }
102 
103  err = Pa_SetStreamFinishedCallback( stream, &Sine::paStreamFinished );
104 
105  if (err != paNoError)
106  {
107  Pa_CloseStream( stream );
108  stream = 0;
109 
110  return false;
111  }
112 
113  return true;
114  }
115 
116  bool close()
117  {
118  if (stream == 0)
119  return false;
120 
121  PaError err = Pa_CloseStream( stream );
122  stream = 0;
123 
124  return (err == paNoError);
125  }
126 
127 
128  bool start()
129  {
130  if (stream == 0)
131  return false;
132 
133  PaError err = Pa_StartStream( stream );
134 
135  return (err == paNoError);
136  }
137 
138  bool stop()
139  {
140  if (stream == 0)
141  return false;
142 
143  PaError err = Pa_StopStream( stream );
144 
145  return (err == paNoError);
146  }
147 
148 private:
149  /* The instance callback, where we have access to every method/variable in object of class Sine */
150  int paCallbackMethod(const void *inputBuffer, void *outputBuffer,
151  unsigned long framesPerBuffer,
152  const PaStreamCallbackTimeInfo* timeInfo,
153  PaStreamCallbackFlags statusFlags)
154  {
155  float *out = (float*)outputBuffer;
156  unsigned long i;
157 
158  (void) timeInfo; /* Prevent unused variable warnings. */
159  (void) statusFlags;
160  (void) inputBuffer;
161 
162  for( i=0; i<framesPerBuffer; i++ )
163  {
164  *out++ = sine[left_phase]; /* left */
165  *out++ = sine[right_phase]; /* right */
166  left_phase += 1;
167  if( left_phase >= TABLE_SIZE ) left_phase -= TABLE_SIZE;
168  right_phase += 3; /* higher pitch so we can distinguish left and right. */
169  if( right_phase >= TABLE_SIZE ) right_phase -= TABLE_SIZE;
170  }
171 
172  return paContinue;
173 
174  }
175 
176  /* This routine will be called by the PortAudio engine when audio is needed.
177  ** It may called at interrupt level on some machines so don't do anything
178  ** that could mess up the system like calling malloc() or free().
179  */
180  static int paCallback( const void *inputBuffer, void *outputBuffer,
181  unsigned long framesPerBuffer,
182  const PaStreamCallbackTimeInfo* timeInfo,
183  PaStreamCallbackFlags statusFlags,
184  void *userData )
185  {
186  /* Here we cast userData to Sine* type so we can call the instance method paCallbackMethod, we can do that since
187  we called Pa_OpenStream with 'this' for userData */
188  return ((Sine*)userData)->paCallbackMethod(inputBuffer, outputBuffer,
189  framesPerBuffer,
190  timeInfo,
191  statusFlags);
192  }
193 
194 
195  void paStreamFinishedMethod()
196  {
197  printf( "Stream Completed: %s\n", message );
198  }
199 
200  /*
201  * This routine is called by portaudio when playback is done.
202  */
203  static void paStreamFinished(void* userData)
204  {
205  return ((Sine*)userData)->paStreamFinishedMethod();
206  }
207 
208  PaStream *stream;
209  float sine[TABLE_SIZE];
210  int left_phase;
211  int right_phase;
212  char message[20];
213 };
214 
215 
216 /*******************************************************************/
217 int main(void);
218 int main(void)
219 {
220  PaError err;
221  Sine sine;
222 
223  printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
224 
225  err = Pa_Initialize();
226  if( err != paNoError ) goto error;
227 
228  if (sine.open(Pa_GetDefaultOutputDevice()))
229  {
230  if (sine.start())
231  {
232  printf("Play for %d seconds.\n", NUM_SECONDS );
233  Pa_Sleep( NUM_SECONDS * 1000 );
234 
235  sine.stop();
236  }
237 
238  sine.close();
239  }
240 
241  Pa_Terminate();
242  printf("Test finished.\n");
243 
244  return err;
245 
246 error:
247  Pa_Terminate();
248  fprintf( stderr, "An error occured while using the portaudio stream\n" );
249  fprintf( stderr, "Error number: %d\n", err );
250  fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
251  return err;
252 }

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