Increase disable_filter_search_var_thresh threshold

Increased threshold(t) for interp filter search. This sped up the
encoder with some PSNR loss.

Borg tests were ran at speed 2.
t = 100, PSNR loss:
-0.710%(derf); -0.561%(stdhd); -0.647%(youtube)
speedup:
9%(derf); 3%(stdhd); 5.7%(youtube)

t = 500, PSNR loss:
-1.687%(derf); -1.665%(stdhd); -1.664%(youtube)
speedup:
18%(derf); 10%(stdhd); 8%(youtube)

Change-Id: I180e3657c1e156aaa88dc7c437f8bcbd19f5caba

vp9/encoder/vp9_onyx_if.c

@@ -745,7 +745,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->adaptive_motion_search = 1;
         sf->auto_mv_step_size = 1;
 
-        sf->disable_filter_search_var_thresh = 16;
+        sf->disable_filter_search_var_thresh = 50;
         sf->comp_inter_joint_search_thresh = BLOCK_SIZES;
 
         sf->auto_min_max_partition_size = 1;
@@ -780,7 +780,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->adaptive_motion_search = 1;
         sf->auto_mv_step_size = 1;
 
-        sf->disable_filter_search_var_thresh = 16;
+        sf->disable_filter_search_var_thresh = 100;
         sf->comp_inter_joint_search_thresh = BLOCK_SIZES;
 
         sf->auto_min_max_partition_size = 1;
@@ -813,7 +813,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->adaptive_motion_search = 1;
         sf->auto_mv_step_size = 1;
 
-        sf->disable_filter_search_var_thresh = 16;
+        sf->disable_filter_search_var_thresh = 200;
         sf->comp_inter_joint_search_thresh = BLOCK_SIZES;
 
         sf->auto_min_max_partition_size = 1;
@@ -859,7 +859,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
         sf->search_method = HEX;
         sf->subpel_iters_per_step = 1;
         sf->disable_split_var_thresh = 64;
-        sf->disable_filter_search_var_thresh = 96;
+        sf->disable_filter_search_var_thresh = 500;
         for (i = 0; i < TX_SIZES; i++) {
           sf->intra_y_mode_mask[i] = INTRA_DC_ONLY;
           sf->intra_uv_mode_mask[i] = INTRA_DC_ONLY;