shithub: dav1d

Download patch

ref: 285d1b7641df768621b57787a7ae3c20d6f6794d
parent: e0a05e5e1a73d0b2b0eb78f4a9c251ffa7331bb1
author: Luc Trudeau <[email protected]>
date: Wed Oct 31 07:46:27 EDT 2018

Remove dav1d_sgr_one_by_x

Since n equals either 25 or 9, the dav1d_sgr_one_by_x table can be
replaced with a ternary operation.

--- a/src/looprestoration_tmpl.c
+++ b/src/looprestoration_tmpl.c
@@ -412,6 +412,8 @@
                               const ptrdiff_t src_stride, const int w,
                               const int h, const int n, const int s)
 {
+    const int sgr_one_by_x = n == 25 ? 164 : 455;
+
     // Selfguided filter is applied to a maximum stripe height of 64 + 3 pixels
     // of padding above and below
     int32_t A_[70 /*(64 + 3 + 3)*/ * REST_UNIT_STRIDE];
@@ -444,7 +446,7 @@
 
             const int x = dav1d_sgr_x_by_xplus1[imin(z, 255)];
             // This is where we invert A and B, so that B is of size coef.
-            AA[i] = (((1 << 8) - x) * BB[i] * dav1d_sgr_one_by_x[n - 1] + (1 << 11)) >> 12;
+            AA[i] = (((1 << 8) - x) * BB[i] * sgr_one_by_x + (1 << 11)) >> 12;
             BB[i] = x;
         }
         AA += step * REST_UNIT_STRIDE;
--- a/src/tables.c
+++ b/src/tables.c
@@ -523,11 +523,6 @@
   256,
 };
 
-const int16_t dav1d_sgr_one_by_x[25] = {
-  4096, 2048, 1365, 1024, 819, 683, 585, 512, 455, 410, 372, 341, 315,
-  293,  273,  256,  241,  228, 216, 205, 195, 186, 178, 171, 164,
-};
-
 const int8_t ALIGN(dav1d_mc_subpel_filters[5][15][8], 8) = {
     [FILTER_8TAP_REGULAR] = {
         {   0,   1,  -3,  63,   4,  -1,   0,   0 },