Super-xBR tweakable antiringing patch for mpv

0001-vo_opengl-Super-xBR-add-antiring-and-offset-bias-sub.patch

From e7acb9ce6e1785b2c2166ddad9705fea779e3e14 Mon Sep 17 00:00:00 2001
From: example <[email protected]>
Date: Mon, 9 May 2016 17:23:50 +0300
Subject: [PATCH] vo_opengl: Super-xBR: add antiring and offset-bias suboptions

Add Hyllian's tweakable antiringing algorithm. superxbr-antiring
suboption can be between 0.0 and 1.0 (default=0). Add offset-bias
setting to tweak how Super-xBR is applied, setting this to lower values
can help with having thinner edges.
superxbr-offset-bias suboption can be between 0.01 and 1.0
(default=1.0).
---
 DOCS/man/vo.rst             |  5 +++--
 video/out/opengl/superxbr.c | 48 ++++++++++++++++++++++++++++-----------------
 2 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/DOCS/man/vo.rst b/DOCS/man/vo.rst
index bf3fb2e..8be6dd2 100644
--- a/DOCS/man/vo.rst
+++ b/DOCS/man/vo.rst
@@ -593,8 +593,9 @@ Available video output drivers are:
         ``superxbr``
             A relatively fast prescaler originally developed for pixel art.
 
-            Some parameters can be tuned with ``superxbr-sharpness`` and
-            ``superxbr-edge-strength`` options.
+            Some parameters that can be tuned with are
+            ``superxbr-sharpness``, ``superxbr-edge-strength``,
+            ``superxbr-antiring`` and ``superxbr-offset-bias`` options.
 
         ``nnedi3``
             An artificial neural network based deinterlacer, which can be used
diff --git a/video/out/opengl/superxbr.c b/video/out/opengl/superxbr.c
index 323ed18..0df04f0 100644
--- a/video/out/opengl/superxbr.c
+++ b/video/out/opengl/superxbr.c
@@ -27,11 +27,15 @@
 struct superxbr_opts {
     float sharpness;
     float edge_strength;
+    float antiring;
+    float offset_bias;
 };
 
 const struct superxbr_opts superxbr_opts_def = {
     .sharpness = 1.0f,
     .edge_strength = 0.6f,
+    .antiring = 0.0f,
+    .offset_bias = 1.0f,
 };
 
 #define OPT_BASE_STRUCT struct superxbr_opts
@@ -39,6 +43,8 @@ const struct m_sub_options superxbr_conf = {
     .opts = (const m_option_t[]) {
         OPT_FLOATRANGE("sharpness", sharpness, 0, 0.0, 2.0),
         OPT_FLOATRANGE("edge-strength", edge_strength, 0, 0.0, 1.0),
+        OPT_FLOATRANGE("antiring", antiring, 0, 0.0, 1.0),
+        OPT_FLOATRANGE("offset-bias", offset_bias, 0, 0.01, 1.0),
         {0}
     },
     .size = sizeof(struct superxbr_opts),
@@ -137,17 +143,17 @@ static void superxbr_step_h(struct gl_shader_cache *sc,
         for (int y = 0; y < 3; y++) {
             if (mask->d1[x][y]) {
                 // 1-distance diagonal neighbours
-                GLSLHF("d_edge += %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->d1[x][y], x+1, y, x, y+1);
-                GLSLHF("d_edge -= %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->d1[x][y], 3-y, x+1, 3-(y+1), x); // rotated
+                GLSLHF("d_edge += %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->d1[x][y], x+1, y, x, y+1, conf->offset_bias);
+                GLSLHF("d_edge -= %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->d1[x][y], 3-y, x+1, 3-(y+1), x, conf->offset_bias); // rotated
             }
             if (x < 2 && y < 2 && mask->d2[x][y]) {
                 // 2-distance diagonal neighbours
-                GLSLHF("d_edge += %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->d2[x][y], x+2, y, x, y+2);
-                GLSLHF("d_edge -= %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->d2[x][y], 3-y, x+2, 3-(y+2), x); // rotated
+                GLSLHF("d_edge += %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->d2[x][y], x+2, y, x, y+2, conf->offset_bias);
+                GLSLHF("d_edge -= %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->d2[x][y], 3-y, x+2, 3-(y+2), x, conf->offset_bias); // rotated
             }
         }
     }
@@ -158,17 +164,17 @@ static void superxbr_step_h(struct gl_shader_cache *sc,
         for (int y = 0; y < 3; y++) {
             if (mask->o1[y]) {
                 // 1-distance neighbours
-                GLSLHF("o_edge += %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->o1[y], x, y, x, y+1); // vertical
-                GLSLHF("o_edge -= %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->o1[y], y, x, y+1, x); // horizontal
+                GLSLHF("o_edge += %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->o1[y], x, y, x, y+1, conf->offset_bias); // vertical
+                GLSLHF("o_edge -= %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->o1[y], y, x, y+1, x, conf->offset_bias); // horizontal
             }
             if (y < 2 && mask->o2[y]) {
                 // 2-distance neighbours
-                GLSLHF("o_edge += %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->o2[y], x, y, x, y+2); // vertical
-                GLSLHF("o_edge -= %d * abs(i(%d,%d) - i(%d,%d));\n",
-                       mask->o2[x], y, x, y+2, x); // horizontal
+                GLSLHF("o_edge += %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->o2[y], x, y, x, y+2, conf->offset_bias); // vertical
+                GLSLHF("o_edge -= %d * abs(i(%d,%d) - i(%d,%d)) * %f;\n",
+                       mask->o2[x], y, x, y+2, x, conf->offset_bias); // horizontal
             }
         }
     }
@@ -180,8 +186,14 @@ static void superxbr_step_h(struct gl_shader_cache *sc,
                     mix(hc,   vc, step(0.0, o_edge)), 1.0 - str);)
 
     // Anti-ringing using center square
-    GLSLH(float lo = min(min( i(1,1), i(2,1) ), min( i(1,2), i(2,2) ));)
-    GLSLH(float hi = max(max( i(1,1), i(2,1) ), max( i(1,2), i(2,2) ));)
+    GLSLHF("float lo = min(min( i(1,1), i(2,1) ), min( i(1,2), i(2,2) )) \
+                       + %f * mix(( i(0,3) - i(1,2) ) * ( i(2,1) - i(3,0) ), \
+                                  ( i(0,0) - i(1,1) ) * ( i(2,2) - i(3,3) ), \
+                                  step(0.0, d_edge));", conf->antiring);
+    GLSLHF("float hi = max(max( i(1,1), i(2,1) ), max( i(1,2), i(2,2) )) \
+                       - %f * mix(( i(0,3) - i(1,2) ) * ( i(2,1)- i(3,0) ), \
+                                  ( i(0,0) - i(1,1) ) * ( i(2,2) - i(3,3) ), \
+                                  step(0.0, d_edge));", conf->antiring);
     GLSLH(res = clamp(res, lo, hi);)
 
     GLSLHF("} // step\n");
-- 
2.5.0