samplefilt: add function to correct accumulated offsets

Analogously to SST_CorrectOffset(), add SPF_CorrectOffset() to correct
the offsets accumulated in the filter.
This commit is contained in:
Miroslav Lichvar 2022-02-24 08:44:10 +01:00
parent 3196630fb9
commit d5e645eb38
3 changed files with 38 additions and 10 deletions

View file

@ -410,6 +410,27 @@ SPF_GetFilteredSample(SPF_Instance filter, NTP_Sample *sample)
return 1;
}
/* ================================================== */
static int
get_first_last(SPF_Instance filter, int *first, int *last)
{
if (filter->last < 0)
return 0;
/* Always slew the last sample as it may be returned even if no new
samples were accumulated */
if (filter->used > 0) {
*first = 0;
*last = filter->used - 1;
} else {
*first = *last = filter->last;
}
return 1;
}
/* ================================================== */
void
@ -418,18 +439,9 @@ SPF_SlewSamples(SPF_Instance filter, struct timespec *when, double dfreq, double
int i, first, last;
double delta_time;
if (filter->last < 0)
if (!get_first_last(filter, &first, &last))
return;
/* Always slew the last sample as it may be returned even if no new
samples were accumulated */
if (filter->used > 0) {
first = 0;
last = filter->used - 1;
} else {
first = last = filter->last;
}
for (i = first; i <= last; i++) {
UTI_AdjustTimespec(&filter->samples[i].time, when, &filter->samples[i].time,
&delta_time, dfreq, doffset);
@ -439,6 +451,20 @@ SPF_SlewSamples(SPF_Instance filter, struct timespec *when, double dfreq, double
/* ================================================== */
void
SPF_CorrectOffset(SPF_Instance filter, double doffset)
{
int i, first, last;
if (!get_first_last(filter, &first, &last))
return;
for (i = first; i <= last; i++)
filter->samples[i].offset -= doffset;
}
/* ================================================== */
void
SPF_AddDispersion(SPF_Instance filter, double dispersion)
{

View file

@ -44,6 +44,7 @@ extern void SPF_DropSamples(SPF_Instance filter);
extern int SPF_GetFilteredSample(SPF_Instance filter, NTP_Sample *sample);
extern void SPF_SlewSamples(SPF_Instance filter, struct timespec *when,
double dfreq, double doffset);
extern void SPF_CorrectOffset(SPF_Instance filter, double doffset);
extern void SPF_AddDispersion(SPF_Instance filter, double dispersion);
#endif

View file

@ -69,6 +69,7 @@ test_unit(void)
TEST_CHECK(!memcmp(&sample_in, &sample_out, sizeof (sample_in)));
SPF_SlewSamples(filter, &sample_in.time, 0.0, 0.0);
SPF_CorrectOffset(filter, 0.0);
SPF_AddDispersion(filter, 0.0);
if (k + 1 < min_samples)