void main_loop_reverse(void) {
LTCFrame f;
const long long int end = ceil(duration * samplerate / 1000.0);
long long int written = 0;
active=1;
short *snd = NULL;
const short smult = rint(pow(10, volume_dbfs/20.0) * 32767.0);
while(active==1 && (duration <= 0 || end >= written)) {
int byteCnt;
for (byteCnt = 9; byteCnt >= 0; byteCnt--) {
int i;
ltc_encoder_encode_byte(encoder, byteCnt, -1.0);
const int len = ltc_encoder_get_buffer(encoder, enc_buf);
if (!snd) snd = malloc(len * sizeof(short));
for (i=0;i<len;i++) {
const short val = ( (int)(enc_buf[i] - 128) * smult / 90 );
snd[i] = val;
}
sf_writef_short(sf, snd, len);
written += len;
if (end < written) break;
} /* end byteCnt - one video frames's worth of LTC */
ltc_encoder_get_frame(encoder, &f);
ltc_frame_decrement(&f, ceil(fps_num/fps_den),
fps_num/(double)fps_den == 25.0? LTC_TV_625_50 : LTC_TV_525_60,
LTC_USE_DATE);
ltc_encoder_set_frame(encoder, &f);
}
free(snd);
printf("wrote %lld audio-samples\n", written);
}
int detect_discontinuity(LTCFrameExt *frame, LTCFrameExt *prev, int fps, int use_date, int fuzzyfps) {
int discontinuity_detected = 0;
if (fuzzyfps && (
(frame->reverse && prev->ltc.frame_units == 0)
||(!frame->reverse && frame->ltc.frame_units == 0)
)){
memcpy(prev, frame, sizeof(LTCFrameExt));
return 0;
}
if (frame->reverse)
ltc_frame_decrement(&prev->ltc, fps,
fps == 25? LTC_TV_625_50 : LTC_TV_525_60, use_date?LTC_USE_DATE:0);
else
ltc_frame_increment(&prev->ltc, fps,
fps == 25? LTC_TV_625_50 : LTC_TV_525_60, use_date?LTC_USE_DATE:0);
if (cmp_ltc_frametime(&prev->ltc, &frame->ltc, use_date?1:0))
discontinuity_detected = 1;
memcpy(prev, frame, sizeof(LTCFrameExt));
return discontinuity_detected;
}
int ltc_encoder_dec_timecode(LTCEncoder *e) {
return ltc_frame_decrement (&e->f, rint(e->fps), e->standard, e->flags);
}
int ltc_frame_decrement(LTCFrame* frame, int fps, enum LTC_TV_STANDARD standard, int flags) {
int rv = 0;
int frames = frame->frame_units + frame->frame_tens * 10;
if (frames > 0) {
frames--;
} else {
frames = fps -1;
}
frame->frame_units = frames % 10;
frame->frame_tens = frames / 10;
if (frames == fps -1) {
int secs = frame->secs_units + frame->secs_tens * 10;
if (secs > 0) {
secs--;
} else {
secs = 59;
}
frame->secs_units = secs % 10;
frame->secs_tens = secs / 10;
if (secs == 59) {
int mins = frame->mins_units + frame->mins_tens * 10;
if (mins > 0) {
mins--;
} else {
mins = 59;
}
frame->mins_units = mins % 10;
frame->mins_tens = mins / 10;
if (mins == 59) {
int hours = frame->hours_units + frame->hours_tens * 10;
if (hours > 0) {
hours--;
} else {
hours = 23;
}
frame->hours_units = hours % 10;
frame->hours_tens = hours / 10;
if (hours == 23) {
/* 24h wrap around */
rv=1;
if (flags<C_USE_DATE)
{
/* wrap date */
SMPTETimecode stime;
stime.years = frame->user5 + frame->user6*10;
stime.months = frame->user3 + frame->user4*10;
stime.days = frame->user1 + frame->user2*10;
if (stime.months > 0 && stime.months < 13)
{
unsigned char dpm[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
/* proper leap-year calc:
* ((stime.years%4)==0 && ( (stime.years%100) != 0 || (stime.years%400) == 0) )
* simplified since year is 0..99
*/
if ((stime.years%4)==0 /* && stime.years!=0 */ ) /* year 2000 was a leap-year */
dpm[1]=29;
//
if (stime.days > 1) {
stime.days--;
} else {
stime.months = 1 + (stime.months + 10)%12;
stime.days = dpm[stime.months-1];
if (stime.months == 12) {
stime.years=(stime.years+99)%100; // XXX
}
}
frame->user6 = stime.years/10;
frame->user5 = stime.years%10;
frame->user4 = stime.months/10;
frame->user3 = stime.months%10;
frame->user2 = stime.days/10;
frame->user1 = stime.days%10;
} else {
rv=-1;
}
}
}
}
}
}
if (frame->dfbit && /* prevent endless recursion */ fps > 2) {
if ((frame->mins_units != 0)
&& (frame->secs_units == 0)
&& (frame->secs_tens == 0)
&& (frame->frame_units == 1)
&& (frame->frame_tens == 0)
) {
ltc_frame_decrement(frame, fps, standard, flags<C_USE_DATE);
ltc_frame_decrement(frame, fps, standard, flags<C_USE_DATE);
}
}
if ((flags & LTC_NO_PARITY) == 0) {
ltc_frame_set_parity(frame, standard);
}
return rv;
}