added naive calibration header detection

pull/6/head
Ahmet Inan 2014-11-24 18:11:06 +01:00
rodzic bab8445d39
commit 273c97fb65
1 zmienionych plików z 49 dodań i 0 usunięć

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@ -118,6 +118,9 @@ static float dat_fmd(float2 baseband)
}
static int sample_rate, mode, even_hpos;
static int calibration_length, calibration_timeout;
static int calibration_progress, leader_counter, leader_length;
static int break_length, break_counter, vis_counter, vis_length;
static int buffer_length, bitmap_width, bitmap_height;
static int sync_length, sync_counter, vpos, hpos;
static int save_cnt, save_dat, seperator_counter;
@ -323,6 +326,22 @@ void initialize(float rate, int length, int width, int height)
sync_counter = 0;
seperator_counter = 0;
const float leader_tolerance = 0.7f;
const float break_tolerance = 0.7f;
const float timeout_tolerance = 1.1f;
const float leader_len = 0.3f;
const float break_len = 0.01f;
const float vis_len = 0.3f;
calibration_progress = 0;
calibration_timeout = 0;
leader_counter = 0;
break_counter = 0;
vis_counter = 0;
leader_length = leader_tolerance * leader_len * sample_rate;
break_length = break_tolerance * break_len * sample_rate;
vis_length = vis_len * sample_rate;
calibration_length = timeout_tolerance * (break_len + leader_len + vis_len) * sample_rate;
const float dat_carrier = 1900.0f;
const float cnt_carrier = 1200.0f;
const float dat_bandwidth = 800.0f;
@ -410,6 +429,7 @@ void decode(int samples) {
float dat_value = dat_fmd(dat_baseband);
int cnt_active = cabs(dat_baseband) < cabs(cnt_baseband);
int dat_active = !cnt_active;
uchar cnt_level = save_cnt ? 127.5f - 127.5f * cnt_value : 0.0f;
uchar dat_level = save_dat ? 127.5f + 127.5f * dat_value : 0.0f;
value_buffer[hpos] = cnt_active ? cnt_level : dat_level;
@ -417,6 +437,35 @@ void decode(int samples) {
int cnt_quantized = round(cnt_value);
int dat_quantized = round(dat_value);
calibration_progress = calibration_timeout ? calibration_progress : 0;
calibration_timeout -= !!calibration_timeout;
int leader_level = dat_active && dat_quantized == 0;
int leader_pulse = !leader_level && leader_counter >= leader_length;
leader_counter = leader_level ? leader_counter + 1 : 0;
calibration_progress = leader_pulse && calibration_progress != 1 ? (calibration_progress == 2 ? 1 : 3) : calibration_progress;
calibration_timeout = leader_pulse && calibration_progress == 1 ? calibration_length : calibration_timeout;
int break_level = cnt_active && cnt_quantized == 0;
int break_pulse = !break_level && break_counter >= break_length;
break_counter = break_level ? break_counter + 1 : 0;
calibration_progress = break_pulse && calibration_progress != 3 ? (calibration_progress == 1 ? 2 : 0) : calibration_progress;
if (calibration_progress > 2) {
vpos = 0;
hpos = 0;
even_hpos = 0;
seperator_counter = 0;
sync_counter = sync_length;
if (++vis_counter >= vis_length) {
calibration_progress = 0;
calibration_timeout = 0;
vis_counter = 0;
for (int i = 0; i < bitmap_width * bitmap_height; ++i)
pixel_buffer[i] = rgb(0, 0, 0);
}
}
int sync_level = cnt_active && cnt_quantized == 0;
int sync_pulse = !sync_level && sync_counter >= sync_length;
sync_counter = sync_level ? sync_counter + 1 : 0;