ref: a9f479682ac36288d63f2851f5d13a51be20a7ac
dir: /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 "vp9/common/vp9_filter.h"
const InterpKernel 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 InterpKernel,
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 InterpKernel,
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 InterpKernel,
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}
};
static const InterpKernel* vp9_filter_kernels[4] = {
vp9_sub_pel_filters_8,
vp9_sub_pel_filters_8lp,
vp9_sub_pel_filters_8s,
vp9_bilinear_filters
};
const InterpKernel *vp9_get_interp_kernel(INTERP_FILTER filter) {
assert(filter != SWITCHABLE);
return vp9_filter_kernels[filter];
}