From 28743f1803721b6d0b7dcfcc1cb07c1e58f8cc12 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Wed, 12 Feb 2020 11:25:25 +0100
Subject: [PATCH] avfilter/vf_median: implement percentile option

---
 doc/filters.texi        | 5 +++++
 libavfilter/median.h    | 1 +
 libavfilter/vf_median.c | 3 ++-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 7c25bbaf97..c2af80dd51 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -13289,6 +13289,11 @@ Set which planes to process. Default is @code{15}, which is all available planes
 Set vertical radius size. Default value is @code{0}.
 Allowed range is integer from 0 to 127.
 If it is 0, value will be picked from horizontal @code{radius} option.
+
+@item percentile
+Set median percentile. Default value is @code{0.5}.
+Default value of @code{0.5} will pick always median values, while @code{0} will pick
+minimum values, and @code{1} maximum values.
 @end table
 
 @subsection Commands
diff --git a/libavfilter/median.h b/libavfilter/median.h
index 89ae0472b0..672607caa8 100644
--- a/libavfilter/median.h
+++ b/libavfilter/median.h
@@ -31,6 +31,7 @@ typedef struct MedianContext {
     int planes;
     int radius;
     int radiusV;
+    float percentile;
 
     int planewidth[4];
     int planeheight[4];
diff --git a/libavfilter/vf_median.c b/libavfilter/vf_median.c
index ee264e1a74..0189fabd07 100644
--- a/libavfilter/vf_median.c
+++ b/libavfilter/vf_median.c
@@ -60,6 +60,7 @@ static const AVOption median_options[] = {
     { "radius", "set median radius",    OFFSET(radius), AV_OPT_TYPE_INT,   {.i64=1},     1,  127, FLAGS },
     { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT,   {.i64=0xF},   0,  0xF, FLAGS },
     { "radiusV", "set median vertical radius", OFFSET(radiusV), AV_OPT_TYPE_INT, {.i64=0},0, 127, FLAGS },
+    { "percentile", "set median percentile", OFFSET(percentile), AV_OPT_TYPE_FLOAT, {.dbl=.5}, 0., 1., FLAGS },
     { NULL }
 };
 
@@ -127,7 +128,7 @@ static void check_params(MedianContext *s, AVFilterLink *inlink)
         }
     }
 
-    s->t = 2 * s->radius * s->radiusV + 2 * s->radius;
+    s->t = (2 * s->radius * s->radiusV + s->radiusV + s->radius) * 2.f * s->percentile;
 }
 
 static int config_input(AVFilterLink *inlink)