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authorPaul B Mahol <onemda@gmail.com>2015-09-15 09:13:53 +0000
committerPaul B Mahol <onemda@gmail.com>2015-09-15 09:28:40 +0000
commitf2b1df735ed0baa26353abe2dade67e9dc09a922 (patch)
treea1b3badbb4e145c315b0ddc3eb73d85a741fdaa8 /libavfilter/avf_showfreqs.c
parent1c853d5727e287a9f83271590763b71f88681ee1 (diff)
downloadffmpeg-f2b1df735ed0baa26353abe2dade67e9dc09a922.tar.gz
avfilter/avf_showfreqs: add lanczos and gauss windowing functions
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Diffstat (limited to 'libavfilter/avf_showfreqs.c')
-rw-r--r--libavfilter/avf_showfreqs.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/libavfilter/avf_showfreqs.c b/libavfilter/avf_showfreqs.c
index c00e4d8633..5dfa2df4d5 100644
--- a/libavfilter/avf_showfreqs.c
+++ b/libavfilter/avf_showfreqs.c
@@ -39,7 +39,7 @@ enum AmplitudeScale { AS_LINEAR, AS_SQRT, AS_CBRT, AS_LOG, NB_ASCALES };
enum WindowFunc { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,
WFUNC_BARTLETT, WFUNC_WELCH, WFUNC_FLATTOP,
WFUNC_BHARRIS, WFUNC_BNUTTALL, WFUNC_SINE, WFUNC_NUTTALL,
- WFUNC_BHANN, NB_WFUNC };
+ WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, NB_WFUNC };
typedef struct ShowFreqsContext {
const AVClass *class;
@@ -110,6 +110,8 @@ static const AVOption showfreqs_options[] = {
{ "bhann", "Bartlett-Hann", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BHANN}, 0, 0, FLAGS, "win_func" },
{ "sine", "Sine", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE}, 0, 0, FLAGS, "win_func" },
{ "nuttall", "Nuttall", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_NUTTALL}, 0, 0, FLAGS, "win_func" },
+ { "lanczos", "Lanczos", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS}, 0, 0, FLAGS, "win_func" },
+ { "gauss", "Gauss", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS}, 0, 0, FLAGS, "win_func" },
{ "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=1.}, 0., 1., FLAGS },
{ "averaging", "set time averaging", OFFSET(avg), AV_OPT_TYPE_INT, {.i64=1}, 0, INT32_MAX, FLAGS },
{ "colors", "set channels colors", OFFSET(colors), AV_OPT_TYPE_STRING, {.str = "red|green|blue|yellow|orange|lime|pink|magenta|brown" }, 0, 0, FLAGS },
@@ -221,6 +223,17 @@ static void generate_window_func(float *lut, int N, int win_func, float *overlap
lut[n] = 0.355768-0.487396*cos(2*M_PI*n/(N-1))+0.144232*cos(4*M_PI*n/(N-1))-0.012604*cos(6*M_PI*n/(N-1));
*overlap = 0.663;
break;
+ case WFUNC_LANCZOS:
+#define SINC(x) (!(x)) ? 1 : sin(M_PI * (x))/(M_PI * (x));
+ for (n = 0; n < N; n++)
+ lut[n] = SINC((2.*n)/(N-1)-1);
+ *overlap = 0.75;
+ break;
+ case WFUNC_GAUSS:
+ for (n = 0; n < N; n++)
+ lut[n] = pow(M_E,-0.5*pow((n-(N-1)/2)/(0.4*(N-1)/2.f),2));
+ *overlap = 0.75;
+ break;
default:
av_assert0(0);
}