File size: 7,573 Bytes
83418c6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
/** @file patest_maxsines.c
    @ingroup test_src
    @brief How many sine waves can we calculate and play in less than 80% CPU Load.
    @author Ross Bencina <[email protected]>
    @author Phil Burk <[email protected]>
*/
/*
 * $Id$
 *
 * 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 MAX_SINES     (2000)
#define MAX_USAGE     (0.5)
#define SAMPLE_RATE   (44100)
#define FREQ_TO_PHASE_INC(freq)   (freq/(float)SAMPLE_RATE)

#define MIN_PHASE_INC  FREQ_TO_PHASE_INC(200.0f)
#define MAX_PHASE_INC  (MIN_PHASE_INC * (1 << 5))

#define FRAMES_PER_BUFFER  (512)
#ifndef M_PI
#define M_PI  (3.14159265)
#endif
#define TWOPI (M_PI * 2.0)

#define TABLE_SIZE   (1024)

typedef struct paTestData
{
    int numSines;
    float sine[TABLE_SIZE + 1]; /* add one for guard point for interpolation */
    float phases[MAX_SINES];
}
paTestData;

/* Convert phase between 0.0 and 1.0 to sine value
 * using linear interpolation.
 */
float LookupSine( paTestData *data, float phase );
float LookupSine( paTestData *data, float phase )
{
    float fIndex = phase*TABLE_SIZE;
    int   index = (int) fIndex;
    float fract = fIndex - index;
    float lo = data->sine[index];
    float hi = data->sine[index+1];
    float val = lo + fract*(hi-lo);
    return val;
}

/* 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 patestCallback(const void*                     inputBuffer,
                          void*                           outputBuffer,
                          unsigned long                   framesPerBuffer,
                          const PaStreamCallbackTimeInfo* timeInfo,
                          PaStreamCallbackFlags           statusFlags,
                          void*                           userData )
{
    paTestData *data = (paTestData*)userData;
    float *out = (float*)outputBuffer;
    float outSample;
    float scaler;
    int numForScale;
    unsigned long i;
    int j;
    int finished = 0;
    (void) inputBuffer; /* Prevent unused argument warning. */

    /* Determine amplitude scaling factor */
    numForScale = data->numSines;
    if( numForScale < 8 ) numForScale = 8;  /* prevent pops at beginning */
    scaler = 1.0f / numForScale;

    for( i=0; i<framesPerBuffer; i++ )
    {
        float output = 0.0;
        float phaseInc = MIN_PHASE_INC;
        float phase;
        for( j=0; j<data->numSines; j++ )
        {
            /* Advance phase of next oscillator. */
            phase = data->phases[j];
            phase += phaseInc;
            if( phase >= 1.0 ) phase -= 1.0;

            output += LookupSine(data, phase);
            data->phases[j] = phase;

            phaseInc *= 1.02f;
            if( phaseInc > MAX_PHASE_INC ) phaseInc = MIN_PHASE_INC;
        }

        outSample = (float) (output * scaler);
        *out++ = outSample; /* Left */
        *out++ = outSample; /* Right */
    }
    return finished;
}

/*******************************************************************/
int main(void);
int main(void)
{
    int                 i;
    PaStream*           stream;
    PaStreamParameters  outputParameters;
    PaError             err;
    paTestData          data = {0};
    double              load;

    printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);

    /* initialise sinusoidal wavetable */
    for( i=0; i<TABLE_SIZE; i++ )
    {
        data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
    }
    data.sine[TABLE_SIZE] = data.sine[0]; /* set guard point */

    err = Pa_Initialize();
    if( err != paNoError )
        goto error;
    outputParameters.device                    = Pa_GetDefaultOutputDevice(); /* Default output device. */
    if (outputParameters.device == paNoDevice) {
        fprintf(stderr,"Error: No default output device.\n");
        goto error;
    }
    outputParameters.channelCount              = 2;                           /* Stereo output. */
    outputParameters.sampleFormat              = paFloat32;                   /* 32 bit floating point output. */
    outputParameters.hostApiSpecificStreamInfo = NULL;
    outputParameters.suggestedLatency          = Pa_GetDeviceInfo(outputParameters.device)
                                                 ->defaultHighOutputLatency;
    err = Pa_OpenStream(&stream,
                        NULL,               /* no input */
                        &outputParameters,
                        SAMPLE_RATE,
                        FRAMES_PER_BUFFER,
                        paClipOff,          /* No out of range samples should occur. */
                        patestCallback,
                        &data);
    if( err != paNoError )
        goto error;

    err = Pa_StartStream( stream );
    if( err != paNoError )
        goto error;

    /* Play an increasing number of sine waves until we hit MAX_USAGE */
    do  {
        data.numSines += 10;
        Pa_Sleep(200);
        load = Pa_GetStreamCpuLoad(stream);
        printf("numSines = %d, CPU load = %f\n", data.numSines, load );
        fflush(stdout);
        } while((load < MAX_USAGE) && (data.numSines < MAX_SINES));

    Pa_Sleep(2000);     /* Stay for 2 seconds at max CPU. */

    err = Pa_StopStream( stream );
    if( err != paNoError )
        goto error;

    err = Pa_CloseStream( stream );
    if( err != paNoError )
        goto error;

    Pa_Terminate();
    printf("Test finished.\n");
    return err;
error:
    Pa_Terminate();
    fprintf( stderr, "An error occurred while using the portaudio stream\n" );
    fprintf( stderr, "Error number: %d\n", err );
    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
    return err;
}