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  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,
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 
222 {
223 public:
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 }