vp9/common/vp9_filter.c

/*
 *  Copyright (c) 2010 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.
 */

#include <assert.h>

#include "vpx_ports/mem.h"

#include "vp9/common/vp9_filter.h"

DECLARE_ALIGNED(256, const subpel_kernel,
                vp9_bilinear_filters[SUBPEL_SHIFTS]) = {
  { 0, 0, 0, 128,   0, 0, 0, 0 },
  { 0, 0, 0, 120,   8, 0, 0, 0 },
  { 0, 0, 0, 112,  16, 0, 0, 0 },
  { 0, 0, 0, 104,  24, 0, 0, 0 },
  { 0, 0, 0,  96,  32, 0, 0, 0 },
  { 0, 0, 0,  88,  40, 0, 0, 0 },
  { 0, 0, 0,  80,  48, 0, 0, 0 },
  { 0, 0, 0,  72,  56, 0, 0, 0 },
  { 0, 0, 0,  64,  64, 0, 0, 0 },
  { 0, 0, 0,  56,  72, 0, 0, 0 },
  { 0, 0, 0,  48,  80, 0, 0, 0 },
  { 0, 0, 0,  40,  88, 0, 0, 0 },
  { 0, 0, 0,  32,  96, 0, 0, 0 },
  { 0, 0, 0,  24, 104, 0, 0, 0 },
  { 0, 0, 0,  16, 112, 0, 0, 0 },
  { 0, 0, 0,   8, 120, 0, 0, 0 }
};

// Lagrangian interpolation filter
DECLARE_ALIGNED(256, const subpel_kernel,
                vp9_sub_pel_filters_8[SUBPEL_SHIFTS]) = {
  { 0,   0,   0, 128,   0,   0,   0,  0},
  { 0,   1,  -5, 126,   8,  -3,   1,  0},
  { -1,   3, -10, 122,  18,  -6,   2,  0},
  { -1,   4, -13, 118,  27,  -9,   3, -1},
  { -1,   4, -16, 112,  37, -11,   4, -1},
  { -1,   5, -18, 105,  48, -14,   4, -1},
  { -1,   5, -19,  97,  58, -16,   5, -1},
  { -1,   6, -19,  88,  68, -18,   5, -1},
  { -1,   6, -19,  78,  78, -19,   6, -1},
  { -1,   5, -18,  68,  88, -19,   6, -1},
  { -1,   5, -16,  58,  97, -19,   5, -1},
  { -1,   4, -14,  48, 105, -18,   5, -1},
  { -1,   4, -11,  37, 112, -16,   4, -1},
  { -1,   3,  -9,  27, 118, -13,   4, -1},
  { 0,   2,  -6,  18, 122, -10,   3, -1},
  { 0,   1,  -3,   8, 126,  -5,   1,  0}
};

// DCT based filter
DECLARE_ALIGNED(256, const subpel_kernel,
                vp9_sub_pel_filters_8s[SUBPEL_SHIFTS]) = {
  {0,   0,   0, 128,   0,   0,   0, 0},
  {-1,   3,  -7, 127,   8,  -3,   1, 0},
  {-2,   5, -13, 125,  17,  -6,   3, -1},
  {-3,   7, -17, 121,  27, -10,   5, -2},
  {-4,   9, -20, 115,  37, -13,   6, -2},
  {-4,  10, -23, 108,  48, -16,   8, -3},
  {-4,  10, -24, 100,  59, -19,   9, -3},
  {-4,  11, -24,  90,  70, -21,  10, -4},
  {-4,  11, -23,  80,  80, -23,  11, -4},
  {-4,  10, -21,  70,  90, -24,  11, -4},
  {-3,   9, -19,  59, 100, -24,  10, -4},
  {-3,   8, -16,  48, 108, -23,  10, -4},
  {-2,   6, -13,  37, 115, -20,   9, -4},
  {-2,   5, -10,  27, 121, -17,   7, -3},
  {-1,   3,  -6,  17, 125, -13,   5, -2},
  {0,   1,  -3,   8, 127,  -7,   3, -1}
};

// freqmultiplier = 0.5
DECLARE_ALIGNED(256, const subpel_kernel,
                vp9_sub_pel_filters_8lp[SUBPEL_SHIFTS]) = {
  { 0,  0,  0, 128,  0,  0,  0,  0},
  {-3, -1, 32,  64, 38,  1, -3,  0},
  {-2, -2, 29,  63, 41,  2, -3,  0},
  {-2, -2, 26,  63, 43,  4, -4,  0},
  {-2, -3, 24,  62, 46,  5, -4,  0},
  {-2, -3, 21,  60, 49,  7, -4,  0},
  {-1, -4, 18,  59, 51,  9, -4,  0},
  {-1, -4, 16,  57, 53, 12, -4, -1},
  {-1, -4, 14,  55, 55, 14, -4, -1},
  {-1, -4, 12,  53, 57, 16, -4, -1},
  { 0, -4,  9,  51, 59, 18, -4, -1},
  { 0, -4,  7,  49, 60, 21, -3, -2},
  { 0, -4,  5,  46, 62, 24, -3, -2},
  { 0, -4,  4,  43, 63, 26, -2, -2},
  { 0, -3,  2,  41, 63, 29, -2, -2},
  { 0, -3,  1,  38, 64, 32, -1, -3}
};

const subpel_kernel *vp9_get_filter_kernel(INTERPOLATION_TYPE type) {
  switch (type) {
    case EIGHTTAP:
      return vp9_sub_pel_filters_8;
    case EIGHTTAP_SMOOTH:
      return vp9_sub_pel_filters_8lp;
    case EIGHTTAP_SHARP:
      return vp9_sub_pel_filters_8s;
    case BILINEAR:
      return vp9_bilinear_filters;
    default:
      assert(!"Invalid interpolation type.");
      return NULL;
  }
}