libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_filter.h

 /*
  *  Copyright (c) 2011 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 17 matching lines @@
 #define SUBPEL_TAPS 8
 
 typedef enum {
   EIGHTTAP = 0,
   EIGHTTAP_SMOOTH = 1,
   EIGHTTAP_SHARP = 2,
   BILINEAR = 3,
   SWITCHABLE = 4  /* should be the last one */
 } INTERP_FILTER;
 
+// Number of switchable filters
+#define SWITCHABLE_FILTERS 3
+
+// The codec can operate in four possible inter prediction filter mode:
+// 8-tap, 8-tap-smooth, 8-tap-sharp, and switching between the three.
+#define SWITCHABLE_FILTER_CONTEXTS (SWITCHABLE_FILTERS + 1)
+
 typedef int16_t InterpKernel[SUBPEL_TAPS];
 
 const InterpKernel *vp9_get_interp_kernel(INTERP_FILTER filter);
 
 DECLARE_ALIGNED(256, extern const InterpKernel,
                 vp9_bilinear_filters[SUBPEL_SHIFTS]);
 
 // The VP9_BILINEAR_FILTERS_2TAP macro returns a pointer to the bilinear
 // filter kernel as a 2 tap filter.
 #define BILINEAR_FILTERS_2TAP(x) \
   (vp9_bilinear_filters[(x)] + SUBPEL_TAPS/2 - 1)
 
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // VP9_COMMON_VP9_FILTER_H_