xref: /btstack/example/sine_player.c (revision a8d51f092f1b660d0f6921369ad2bc3f9368296c)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "sine_player.c"
39 
40 /* EXAMPLE_START(audio_duplex): Audio Driver - Play Sine
41  *
42  * @text  Play sine to test and validate audio output with simple wave form.
43  */
44 
45 #include "btstack.h"
46 
47 #define TABLE_SIZE_441HZ            100
48 
49 static int sine_phase;
50 
51 static const int16_t sine_int16[] = {
52      0,    2057,    4107,    6140,    8149,   10126,   12062,   13952,   15786,   17557,
53  19260,   20886,   22431,   23886,   25247,   26509,   27666,   28714,   29648,   30466,
54  31163,   31738,   32187,   32509,   32702,   32767,   32702,   32509,   32187,   31738,
55  31163,   30466,   29648,   28714,   27666,   26509,   25247,   23886,   22431,   20886,
56  19260,   17557,   15786,   13952,   12062,   10126,    8149,    6140,    4107,    2057,
57      0,   -2057,   -4107,   -6140,   -8149,  -10126,  -12062,  -13952,  -15786,  -17557,
58 -19260,  -20886,  -22431,  -23886,  -25247,  -26509,  -27666,  -28714,  -29648,  -30466,
59 -31163,  -31738,  -32187,  -32509,  -32702,  -32767,  -32702,  -32509,  -32187,  -31738,
60 -31163,  -30466,  -29648,  -28714,  -27666,  -26509,  -25247,  -23886,  -22431,  -20886,
61 -19260,  -17557,  -15786,  -13952,  -12062,  -10126,   -8149,   -6140,   -4107,   -2057,
62 };
63 
64 static void audio_playback(int16_t * pcm_buffer, uint16_t num_samples_to_write){
65     int count;
66     for (count = 0; count < num_samples_to_write ; count++){
67         pcm_buffer[count * 2]     = sine_int16[sine_phase];
68         pcm_buffer[count * 2 + 1] = sine_int16[sine_phase];
69         sine_phase++;
70         if (sine_phase >= TABLE_SIZE_441HZ){
71             sine_phase -= TABLE_SIZE_441HZ;
72         }
73     }
74 }
75 
76 int btstack_main(int argc, const char * argv[]);
77 int btstack_main(int argc, const char * argv[]){
78     (void)argc;
79     (void)argv;
80 
81     // setup audio playback
82     const btstack_audio_sink_t * audio = btstack_audio_sink_get_instance();
83     if (!audio){
84         printf("BTstack Audio Sink not setup\n");
85         return 10;
86     }
87     audio->init(2, 44100, &audio_playback);
88     audio->start_stream();
89 
90     return 0;
91 }
92 
93 /* EXAMPLE_END */