libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_scale.c

 /*
  *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 15 matching lines @@
 }
 
 static int get_fixed_point_scale_factor(int other_size, int this_size) {
   // Calculate scaling factor once for each reference frame
   // and use fixed point scaling factors in decoding and encoding routines.
   // Hardware implementations can calculate scale factor in device driver
   // and use multiplication and shifting on hardware instead of division.
   return (other_size << REF_SCALE_SHIFT) / this_size;
 }
 
-static int check_scale_factors(int other_w, int other_h,
-                               int this_w, int this_h) {
-  return 2 * this_w >= other_w &&
-         2 * this_h >= other_h &&
-         this_w <= 16 * other_w &&
-         this_h <= 16 * other_h;
-}
-
 MV32 vp9_scale_mv(const MV *mv, int x, int y, const struct scale_factors *sf) {
   const int x_off_q4 = scaled_x(x << SUBPEL_BITS, sf) & SUBPEL_MASK;
   const int y_off_q4 = scaled_y(y << SUBPEL_BITS, sf) & SUBPEL_MASK;
   const MV32 res = {
     scaled_y(mv->row, sf) + y_off_q4,
     scaled_x(mv->col, sf) + x_off_q4
   };
   return res;
 }
 
 void vp9_setup_scale_factors_for_frame(struct scale_factors *sf,
                                        int other_w, int other_h,
                                        int this_w, int this_h) {
-  if (!check_scale_factors(other_w, other_h, this_w, this_h)) {
+  if (!valid_ref_frame_size(other_w, other_h, this_w, this_h)) {
     sf->x_scale_fp = REF_INVALID_SCALE;
     sf->y_scale_fp = REF_INVALID_SCALE;
     return;
   }
 
   sf->x_scale_fp = get_fixed_point_scale_factor(other_w, this_w);
   sf->y_scale_fp = get_fixed_point_scale_factor(other_h, this_h);
   sf->x_step_q4 = scaled_x(16, sf);
   sf->y_step_q4 = scaled_y(16, sf);
 
@@ skipping 45 matching lines @@
       sf->predict[0][1][0] = vp9_convolve8;
       sf->predict[0][1][1] = vp9_convolve8_avg;
       sf->predict[1][0][0] = vp9_convolve8;
       sf->predict[1][0][1] = vp9_convolve8_avg;
     }
   }
   // 2D subpel motion always gets filtered in both directions
   sf->predict[1][1][0] = vp9_convolve8;
   sf->predict[1][1][1] = vp9_convolve8_avg;
 }