File: paex_sine_c++.cpp

package info (click to toggle)
portaudio19 19.6.0-1
  • links: PTS, VCS
  • area: main
  • in suites: buster, stretch
  • size: 7,980 kB
  • ctags: 13,089
  • sloc: ansic: 56,444; sh: 13,640; cpp: 10,851; java: 677; makefile: 339; python: 143
file content (275 lines) | stat: -rw-r--r-- 7,935 bytes parent folder | download | duplicates (10)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
/** @file paex_sine.c
	@ingroup examples_src
	@brief Play a sine wave for several seconds.
	@author Ross Bencina <rossb@audiomulch.com>
    @author Phil Burk <philburk@softsynth.com>
*/
/*
 * $Id: paex_sine.c 1752 2011-09-08 03:21:55Z philburk $
 *
 * This program uses the PortAudio Portable Audio Library.
 * For more information see: http://www.portaudio.com/
 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * The text above constitutes the entire PortAudio license; however, 
 * the PortAudio community also makes the following non-binding requests:
 *
 * Any person wishing to distribute modifications to the Software is
 * requested to send the modifications to the original developer so that
 * they can be incorporated into the canonical version. It is also 
 * requested that these non-binding requests be included along with the 
 * license above.
 */
#include <stdio.h>
#include <math.h>
#include "portaudio.h"

#define NUM_SECONDS   (5)
#define SAMPLE_RATE   (44100)
#define FRAMES_PER_BUFFER  (64)

#ifndef M_PI
#define M_PI  (3.14159265)
#endif

#define TABLE_SIZE   (200)

class Sine
{
public:
    Sine() : stream(0), left_phase(0), right_phase(0)
    {
        /* initialise sinusoidal wavetable */
        for( int i=0; i<TABLE_SIZE; i++ )
        {
            sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
        }

        sprintf( message, "No Message" );
    }

    bool open(PaDeviceIndex index)
    {
        PaStreamParameters outputParameters;

        outputParameters.device = index;
        if (outputParameters.device == paNoDevice) {
            return false;
        }

        const PaDeviceInfo* pInfo = Pa_GetDeviceInfo(index);
        if (pInfo != 0)
        {
            printf("Output device name: '%s'\r", pInfo->name);
        }

        outputParameters.channelCount = 2;       /* stereo output */
        outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
        outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
        outputParameters.hostApiSpecificStreamInfo = NULL;

        PaError err = Pa_OpenStream(
            &stream,
            NULL, /* no input */
            &outputParameters,
            SAMPLE_RATE,
            paFramesPerBufferUnspecified,
            paClipOff,      /* we won't output out of range samples so don't bother clipping them */
            &Sine::paCallback,
            this            /* Using 'this' for userData so we can cast to Sine* in paCallback method */
            );

        if (err != paNoError)
        {
            /* Failed to open stream to device !!! */
            return false;
        }

        err = Pa_SetStreamFinishedCallback( stream, &Sine::paStreamFinished );

        if (err != paNoError)
        {
            Pa_CloseStream( stream );
            stream = 0;

            return false;
        }

        return true;
    }

    bool close()
    {
        if (stream == 0)
            return false;

        PaError err = Pa_CloseStream( stream );
        stream = 0;

        return (err == paNoError);
    }


    bool start()
    {
        if (stream == 0)
            return false;

        PaError err = Pa_StartStream( stream );

        return (err == paNoError);
    }

    bool stop()
    {
        if (stream == 0)
            return false;

        PaError err = Pa_StopStream( stream );

        return (err == paNoError);
    }

private:
    /* The instance callback, where we have access to every method/variable in object of class Sine */
    int paCallbackMethod(const void *inputBuffer, void *outputBuffer,
        unsigned long framesPerBuffer,
        const PaStreamCallbackTimeInfo* timeInfo,
        PaStreamCallbackFlags statusFlags)
    {
        float *out = (float*)outputBuffer;
        unsigned long i;

        (void) timeInfo; /* Prevent unused variable warnings. */
        (void) statusFlags;
        (void) inputBuffer;

        for( i=0; i<framesPerBuffer; i++ )
        {
            *out++ = sine[left_phase];  /* left */
            *out++ = sine[right_phase];  /* right */
            left_phase += 1;
            if( left_phase >= TABLE_SIZE ) left_phase -= TABLE_SIZE;
            right_phase += 3; /* higher pitch so we can distinguish left and right. */
            if( right_phase >= TABLE_SIZE ) right_phase -= TABLE_SIZE;
        }

        return paContinue;

    }

    /* This routine will be called by the PortAudio engine when audio is needed.
    ** It may called at interrupt level on some machines so don't do anything
    ** that could mess up the system like calling malloc() or free().
    */
    static int paCallback( const void *inputBuffer, void *outputBuffer,
        unsigned long framesPerBuffer,
        const PaStreamCallbackTimeInfo* timeInfo,
        PaStreamCallbackFlags statusFlags,
        void *userData )
    {
        /* Here we cast userData to Sine* type so we can call the instance method paCallbackMethod, we can do that since 
           we called Pa_OpenStream with 'this' for userData */
        return ((Sine*)userData)->paCallbackMethod(inputBuffer, outputBuffer,
            framesPerBuffer,
            timeInfo,
            statusFlags);
    }


    void paStreamFinishedMethod()
    {
        printf( "Stream Completed: %s\n", message );
    }

    /*
     * This routine is called by portaudio when playback is done.
     */
    static void paStreamFinished(void* userData)
    {
        return ((Sine*)userData)->paStreamFinishedMethod();
    }

    PaStream *stream;
    float sine[TABLE_SIZE];
    int left_phase;
    int right_phase;
    char message[20];
};

class ScopedPaHandler
{
public:
    ScopedPaHandler()
        : _result(Pa_Initialize())
    {
    }
    ~ScopedPaHandler()
    {
        if (_result == paNoError)
        {
            Pa_Terminate();
        }
    }

    PaError result() const { return _result; }

private:
    PaError _result;
};


/*******************************************************************/
int main(void);
int main(void)
{
    Sine sine;

    printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
    
    ScopedPaHandler paInit;
    if( paInit.result() != paNoError ) goto error;

    if (sine.open(Pa_GetDefaultOutputDevice()))
    {
        if (sine.start())
        {
            printf("Play for %d seconds.\n", NUM_SECONDS );
            Pa_Sleep( NUM_SECONDS * 1000 );

            sine.stop();
        }

        sine.close();
    }

    printf("Test finished.\n");
    return paNoError;

error:
    fprintf( stderr, "An error occured while using the portaudio stream\n" );
    fprintf( stderr, "Error number: %d\n", paInit.result() );
    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( paInit.result() ) );
    return 1;
}