forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
36 lines
757 B
36 lines
757 B
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* Copyright (C) 2012 Samsung Electronics |
|
* R. Chandrasekar <[email protected]> |
|
*/ |
|
|
|
#include <common.h> |
|
#include <sound.h> |
|
|
|
void sound_create_square_wave(unsigned short *data, int size, uint32_t freq) |
|
{ |
|
const int sample = 48000; |
|
const unsigned short amplitude = 16000; /* between 1 and 32767 */ |
|
const int period = freq ? sample / freq : 0; |
|
const int half = period / 2; |
|
|
|
assert(freq); |
|
|
|
/* Make sure we don't overflow our buffer */ |
|
if (size % 2) |
|
size--; |
|
|
|
while (size) { |
|
int i; |
|
for (i = 0; size && i < half; i++) { |
|
size -= 2; |
|
*data++ = amplitude; |
|
*data++ = amplitude; |
|
} |
|
for (i = 0; size && i < period - half; i++) { |
|
size -= 2; |
|
*data++ = -amplitude; |
|
*data++ = -amplitude; |
|
} |
|
} |
|
}
|
|
|