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avfilter/window_func: add kaiser window

This commit is contained in:
Paul B Mahol 2022-10-20 11:55:34 +02:00
parent 37efcb473f
commit 754d52cf42
2 changed files with 32 additions and 2 deletions
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7
doc/filters.texi
View File

@ -1534,6 +1534,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default is @code{hann}.
@ -2960,6 +2961,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default is @code{hann}.
@ -6743,6 +6745,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default is @code{hann}.
@ -29255,6 +29258,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default is @code{hanning}.
@ -29341,6 +29345,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default value is @code{hann}.
@ -29505,6 +29510,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default value is @code{hann}.
@ -29702,6 +29708,7 @@ It accepts the following values:
@item parzen
@item poisson
@item bohman
@item kaiser
@end table
Default value is @code{hann}.

27
libavfilter/window_func.h
View File

@ -31,7 +31,7 @@ enum WindowFunc { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,
WFUNC_BHARRIS, WFUNC_BNUTTALL, WFUNC_SINE, WFUNC_NUTTALL,
WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, WFUNC_TUKEY,
WFUNC_DOLPH, WFUNC_CAUCHY, WFUNC_PARZEN, WFUNC_POISSON,
WFUNC_BOHMAN,
WFUNC_BOHMAN, WFUNC_KAISER,
NB_WFUNC };
#define WIN_FUNC_OPTION(win_func_opt_name, win_func_offset, flag, default_window_func) \
@ -56,7 +56,22 @@ enum WindowFunc { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,
{ "cauchy", "Cauchy", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_CAUCHY}, 0, 0, flag, "win_func" }, \
{ "parzen", "Parzen", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_PARZEN}, 0, 0, flag, "win_func" }, \
{ "poisson", "Poisson", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_POISSON}, 0, 0, flag, "win_func" }, \
{ "bohman", "Bohman", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BOHMAN}, 0, 0, flag, "win_func" }
{ "bohman", "Bohman", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BOHMAN}, 0, 0, flag, "win_func" }, \
{ "kaiser", "Kaiser", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_KAISER}, 0, 0, flag, "win_func" }
static inline double get_i0(double x)
{
double y = 1.0, prev = 1.0, i = 1.0;
while (fabs(prev) > 1e-20) {
double summand = prev * x * x / (4 * i * i);
y += summand;
prev = summand;
i++;
}
return y;
}
static inline void generate_window_func(float *lut, int N, int win_func,
float *overlap)
@ -216,6 +231,14 @@ static inline void generate_window_func(float *lut, int N, int win_func,
}
*overlap = 0.75;
break;
case WFUNC_KAISER:
for (n = 0; n < N; n++) {
double x = 2.0 / (double)(N - 1);
lut[n] = get_i0(12. * sqrt(1. - SQR(n * x - 1.))) / get_i0(12.);
}
*overlap = 0.75;
break;
default:
av_assert0(0);
}