1. ffmpeg
  2. Commit ea58dd2bebf8748be4c2716936e1056dc6c507fc
Browse code

avfilter/window_func: add dolph window

Paul B Mahol authored on 2016/08/16 21:30:43
Showing 5 changed files
doc/filters.texi
History View file @ ea58dd2
... ... 
@@ -16518,6 +16518,7 @@ It accepts the following values:
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 @item lanczos
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 @item gauss
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 @item tukey
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+@item dolph
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 @end table
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 Default is @code{hanning}.
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@@ -16665,6 +16666,7 @@ It accepts the following values:
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 @item lanczos
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 @item gauss
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 @item tukey
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+@item dolph
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 @end table
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 Default value is @code{hann}.
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@@ -16808,6 +16810,7 @@ It accepts the following values:
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 @item lanczos
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 @item gauss
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 @item tukey
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+@item dolph
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 @end table
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 Default value is @code{hann}.
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libavfilter/avf_showfreqs.c
History View file @ ea58dd2
... ... 
@@ -112,6 +112,7 @@ static const AVOption showfreqs_options[] = {
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         { "lanczos",  "Lanczos",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS},  0, 0, FLAGS, "win_func" },
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         { "gauss",    "Gauss",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS},    0, 0, FLAGS, "win_func" },
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         { "tukey",    "Tukey",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_TUKEY},    0, 0, FLAGS, "win_func" },
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+        { "dolph",    "Dolph-Chebyshev",  0, AV_OPT_TYPE_CONST, {.i64=WFUNC_DOLPH},    0, 0, FLAGS, "win_func" },
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     { "overlap",  "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=1.}, 0., 1., FLAGS },
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     { "averaging", "set time averaging", OFFSET(avg), AV_OPT_TYPE_INT, {.i64=1}, 0, INT32_MAX, FLAGS },
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     { "colors", "set channels colors", OFFSET(colors), AV_OPT_TYPE_STRING, {.str = "red|green|blue|yellow|orange|lime|pink|magenta|brown" }, 0, 0, FLAGS },
libavfilter/avf_showspectrum.c
History View file @ ea58dd2
... ... 
@@ -133,6 +133,7 @@ static const AVOption showspectrum_options[] = {
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         { "lanczos",  "Lanczos",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS},  0, 0, FLAGS, "win_func" },
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         { "gauss",    "Gauss",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS},    0, 0, FLAGS, "win_func" },
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         { "tukey",    "Tukey",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_TUKEY},    0, 0, FLAGS, "win_func" },
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+        { "dolph",    "Dolph-Chebyshev",  0, AV_OPT_TYPE_CONST, {.i64=WFUNC_DOLPH},    0, 0, FLAGS, "win_func" },
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     { "orientation", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=VERTICAL}, 0, NB_ORIENTATIONS-1, FLAGS, "orientation" },
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         { "vertical",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=VERTICAL},   0, 0, FLAGS, "orientation" },
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         { "horizontal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=HORIZONTAL}, 0, 0, FLAGS, "orientation" },
... ... 
@@ -942,6 +943,7 @@ static const AVOption showspectrumpic_options[] = {
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         { "lanczos",  "Lanczos",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_LANCZOS},  0, 0, FLAGS, "win_func" },
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         { "gauss",    "Gauss",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_GAUSS},    0, 0, FLAGS, "win_func" },
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         { "tukey",    "Tukey",            0, AV_OPT_TYPE_CONST, {.i64=WFUNC_TUKEY},    0, 0, FLAGS, "win_func" },
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+        { "dolph",    "Dolph-Chebyshev",  0, AV_OPT_TYPE_CONST, {.i64=WFUNC_DOLPH},    0, 0, FLAGS, "win_func" },
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     { "orientation", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=VERTICAL}, 0, NB_ORIENTATIONS-1, FLAGS, "orientation" },
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         { "vertical",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=VERTICAL},   0, 0, FLAGS, "orientation" },
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         { "horizontal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=HORIZONTAL}, 0, 0, FLAGS, "orientation" },
libavfilter/window_func.c
History View file @ ea58dd2
... ... 
@@ -116,6 +116,18 @@ void ff_generate_window_func(float *lut, int N, int win_func, float *overlap)
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         }
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         *overlap = 0.33;
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         break;
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+    case WFUNC_DOLPH: {
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+        double b = cosh(acosh(pow(10., 3)) / (N-1)), sum, t, c, norm = 0;
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+        int j;
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+        for (c = 1 - 1 / (b*b), n = (N-1) / 2; n >= 0; --n) {
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+            for (sum = !n, b = t = j = 1; j <= n && sum != t; b *= (n-j) * (1./j), ++j)
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+                t = sum, sum += (b *= c * (N - n - j) * (1./j));
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+            sum /= (N - 1 - n), sum /= (norm = norm ? norm : sum);
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+            lut[n] = sum;
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+            lut[N - 1 - n] = sum;
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+        }
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+        *overlap = 0.5;}
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+        break;
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     default:
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         av_assert0(0);
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     }
libavfilter/window_func.h
History View file @ ea58dd2
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@@ -25,7 +25,8 @@
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 enum WindowFunc     { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,
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                       WFUNC_BARTLETT, WFUNC_WELCH, WFUNC_FLATTOP,
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                       WFUNC_BHARRIS, WFUNC_BNUTTALL, WFUNC_SINE, WFUNC_NUTTALL,
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-                      WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, WFUNC_TUKEY, NB_WFUNC };
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+                      WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, WFUNC_TUKEY,
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+                      WFUNC_DOLPH, NB_WFUNC };
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 void ff_generate_window_func(float *lut, int N, int win_func, float *overlap);
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