mirror/btstack
1
0
Fork 0
mirror of https://github.com/bluekitchen/btstack.git synced 2025-03-24 13:43:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

sco_util: use 16-bit sine table

Browse Source
This commit is contained in:
Matthias Ringwald 2016-07-25 11:04:15 +02:00
parent 8901a7c412
commit d6a0639857
2 changed files with 45 additions and 16 deletions

40
example/sco_demo_util.c

@ -97,7 +97,8 @@ static uint8_t negotiated_codec = HFP_CODEC_CVSD;
static int num_audio_frames = 0;
#if SCO_DEMO_MODE == SCO_DEMO_MODE_SINE
// input signal: pre-computed sine wave, 160 Hz
// input signal: pre-computed sine wave, 160 Hz at 8 kHz
static const uint8_t sine[] = {
0, 15, 31, 46, 61, 74, 86, 97, 107, 114,
120, 124, 126, 126, 124, 120, 114, 107, 97, 86,
@ -106,6 +107,19 @@ static const uint8_t sine[] = {
136, 142, 149, 159, 170, 182, 195, 210, 225, 241,
};
// input signal: pre-computed sine wave, 160 Hz at 16000 kHz
static const int16_t sine_int16[] = {
0, 2057, 4107, 6140, 8149, 10126, 12062, 13952, 15786, 17557,
19260, 20886, 22431, 23886, 25247, 26509, 27666, 28714, 29648, 30466,
31163, 31738, 32187, 32509, 32702, 32767, 32702, 32509, 32187, 31738,
31163, 30466, 29648, 28714, 27666, 26509, 25247, 23886, 22431, 20886,
19260, 17557, 15786, 13952, 12062, 10126, 8149, 6140, 4107, 2057,
0, -2057, -4107, -6140, -8149, -10126, -12062, -13952, -15786, -17557,
-19260, -20886, -22431, -23886, -25247, -26509, -27666, -28714, -29648, -30466,
-31163, -31738, -32187, -32509, -32702, -32767, -32702, -32509, -32187, -31738,
-31163, -30466, -29648, -28714, -27666, -26509, -25247, -23886, -22431, -20886,
-19260, -17557, -15786, -13952, -12062, -10126, -8149, -6140, -4107, -2057,
};
#ifdef SCO_WAV_FILENAME
@ -186,23 +200,17 @@ static void handle_pcm_data(int16_t * data, int num_samples, int num_channels, i
}
}
static void sco_demo_generate_sine(int16_t * pcm_samples){
int i;
for (i=0; i < hfp_msbc_num_audio_samples_per_frame(); i++){
uint8_t buf[2];
buf[0] = sine[phase++];
if (phase >= sizeof(sine)) phase = 0;
buf[1] = sine[phase++];
if (phase >= sizeof(sine)) phase = 0;
pcm_samples[i] = little_endian_read_16(buf, 0);
}
}
static void sco_demo_fill_audio_frame(void){
if (!hfp_msbc_can_encode_audio_frame_now()) return;
int16_t read_buffer[8*16*2];
sco_demo_generate_sine(read_buffer);
hfp_msbc_encode_audio_frame(read_buffer);
int i;
int16_t sample_buffer[8*16*2];
for (i=0; i < hfp_msbc_num_audio_samples_per_frame(); i++){
sample_buffer[i] = sine_int16[phase++];
if (phase >= (sizeof(sine_int16) / sizeof(int16_t))){
phase = 0;
}
}
hfp_msbc_encode_audio_frame(sample_buffer);
num_audio_frames++;
}

21
test/sbc/sine_table.py Executable file

@ -0,0 +1,21 @@
#!/usr/bin/env python
import math
import sys
SAMPLES = 100
VALUES_PER_LINE = 10
print ('''
// input signal: pre-computed sine wave, 160 Hz at 16000 kHz
static const int16_t sine_int16[] = {''')
items = 0
for sample in range(SAMPLES):
angle = (sample * 360.0) / SAMPLES
sine = math.sin(math.radians(angle))
rescaled = int(round(sine * 32767))
print ("%6d, " % rescaled),
items += 1
if items == VALUES_PER_LINE:
items = 0
print
print( "};")