diff -r 000000000000 -r 6474c204b198 media/libvpx/vp9/common/vp9_scale.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/media/libvpx/vp9/common/vp9_scale.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/*
+ *  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.
+ */
+
+#ifndef VP9_COMMON_VP9_SCALE_H_
+#define VP9_COMMON_VP9_SCALE_H_
+
+#include "vp9/common/vp9_mv.h"
+#include "vp9/common/vp9_convolve.h"
+
+#define REF_SCALE_SHIFT 14
+#define REF_NO_SCALE (1 << REF_SCALE_SHIFT)
+#define REF_INVALID_SCALE -1
+
+struct scale_factors;
+struct scale_factors_common {
+  int x_scale_fp;   // horizontal fixed point scale factor
+  int y_scale_fp;   // vertical fixed point scale factor
+  int x_step_q4;
+  int y_step_q4;
+
+  int (*scale_value_x)(int val, const struct scale_factors_common *sfc);
+  int (*scale_value_y)(int val, const struct scale_factors_common *sfc);
+  void (*set_scaled_offsets)(struct scale_factors *scale, int row, int col);
+  MV32 (*scale_mv)(const MV *mv, const struct scale_factors *scale);
+
+  convolve_fn_t predict[2][2][2];  // horiz, vert, avg
+};
+
+struct scale_factors {
+  int x_offset_q4;
+  int y_offset_q4;
+  const struct scale_factors_common *sfc;
+};
+
+void vp9_setup_scale_factors_for_frame(struct scale_factors *scale,
+                                       struct scale_factors_common *scale_comm,
+                                       int other_w, int other_h,
+                                       int this_w, int this_h);
+
+static int vp9_is_valid_scale(const struct scale_factors_common *sfc) {
+  return sfc->x_scale_fp != REF_INVALID_SCALE &&
+         sfc->y_scale_fp != REF_INVALID_SCALE;
+}
+
+static int vp9_is_scaled(const struct scale_factors_common *sfc) {
+  return sfc->x_scale_fp != REF_NO_SCALE ||
+         sfc->y_scale_fp != REF_NO_SCALE;
+}
+
+#endif  // VP9_COMMON_VP9_SCALE_H_