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/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include "config/av1_rtcd.h"
#include "av1/common/av1_common_int.h"
#include "av1/common/warped_motion.h"
#include "av1/common/scale.h"
// For warping, we really use a 6-tap filter, but we do blocks of 8 pixels
// at a time. The zoom/rotation/shear in the model are applied to the
// "fractional" position of each pixel, which therefore varies within
// [-1, 2) * WARPEDPIXEL_PREC_SHIFTS.
// We need an extra 2 taps to fit this in, for a total of 8 taps.
/* clang-format off */
const int16_t av1_warped_filter[WARPEDPIXEL_PREC_SHIFTS * 3 + 1][8] = {
// [-1, 0)
{ 0, 0, 127, 1, 0, 0, 0, 0 }, { 0, - 1, 127, 2, 0, 0, 0, 0 },
{ 1, - 3, 127, 4, - 1, 0, 0, 0 }, { 1, - 4, 126, 6, - 2, 1, 0, 0 },
{ 1, - 5, 126, 8, - 3, 1, 0, 0 }, { 1, - 6, 125, 11, - 4, 1, 0, 0 },
{ 1, - 7, 124, 13, - 4, 1, 0, 0 }, { 2, - 8, 123, 15, - 5, 1, 0, 0 },
{ 2, - 9, 122, 18, - 6, 1, 0, 0 }, { 2, -10, 121, 20, - 6, 1, 0, 0 },
{ 2, -11, 120, 22, - 7, 2, 0, 0 }, { 2, -12, 119, 25, - 8, 2, 0, 0 },
{ 3, -13, 117, 27, - 8, 2, 0, 0 }, { 3, -13, 116, 29, - 9, 2, 0, 0 },
{ 3, -14, 114, 32, -10, 3, 0, 0 }, { 3, -15, 113, 35, -10, 2, 0, 0 },
{ 3, -15, 111, 37, -11, 3, 0, 0 }, { 3, -16, 109, 40, -11, 3, 0, 0 },
{ 3, -16, 108, 42, -12, 3, 0, 0 }, { 4, -17, 106, 45, -13, 3, 0, 0 },
{ 4, -17, 104, 47, -13, 3, 0, 0 }, { 4, -17, 102, 50, -14, 3, 0, 0 },
{ 4, -17, 100, 52, -14, 3, 0, 0 }, { 4, -18, 98, 55, -15, 4, 0, 0 },
{ 4, -18, 96, 58, -15, 3, 0, 0 }, { 4, -18, 94, 60, -16, 4, 0, 0 },
{ 4, -18, 91, 63, -16, 4, 0, 0 }, { 4, -18, 89, 65, -16, 4, 0, 0 },
{ 4, -18, 87, 68, -17, 4, 0, 0 }, { 4, -18, 85, 70, -17, 4, 0, 0 },
{ 4, -18, 82, 73, -17, 4, 0, 0 }, { 4, -18, 80, 75, -17, 4, 0, 0 },
{ 4, -18, 78, 78, -18, 4, 0, 0 }, { 4, -17, 75, 80, -18, 4, 0, 0 },
{ 4, -17, 73, 82, -18, 4, 0, 0 }, { 4, -17, 70, 85, -18, 4, 0, 0 },
{ 4, -17, 68, 87, -18, 4, 0, 0 }, { 4, -16, 65, 89, -18, 4, 0, 0 },
{ 4, -16, 63, 91, -18, 4, 0, 0 }, { 4, -16, 60, 94, -18, 4, 0, 0 },
{ 3, -15, 58, 96, -18, 4, 0, 0 }, { 4, -15, 55, 98, -18, 4, 0, 0 },
{ 3, -14, 52, 100, -17, 4, 0, 0 }, { 3, -14, 50, 102, -17, 4, 0, 0 },
{ 3, -13, 47, 104, -17, 4, 0, 0 }, { 3, -13, 45, 106, -17, 4, 0, 0 },
{ 3, -12, 42, 108, -16, 3, 0, 0 }, { 3, -11, 40, 109, -16, 3, 0, 0 },
{ 3, -11, 37, 111, -15, 3, 0, 0 }, { 2, -10, 35, 113, -15, 3, 0, 0 },
{ 3, -10, 32, 114, -14, 3, 0, 0 }, { 2, - 9, 29, 116, -13, 3, 0, 0 },
{ 2, - 8, 27, 117, -13, 3, 0, 0 }, { 2, - 8, 25, 119, -12, 2, 0, 0 },
{ 2, - 7, 22, 120, -11, 2, 0, 0 }, { 1, - 6, 20, 121, -10, 2, 0, 0 },
{ 1, - 6, 18, 122, - 9, 2, 0, 0 }, { 1, - 5, 15, 123, - 8, 2, 0, 0 },
{ 1, - 4, 13, 124, - 7, 1, 0, 0 }, { 1, - 4, 11, 125, - 6, 1, 0, 0 },
{ 1, - 3, 8, 126, - 5, 1, 0, 0 }, { 1, - 2, 6, 126, - 4, 1, 0, 0 },
{ 0, - 1, 4, 127, - 3, 1, 0, 0 }, { 0, 0, 2, 127, - 1, 0, 0, 0 },
// [0, 1)
{ 0, 0, 0, 127, 1, 0, 0, 0}, { 0, 0, -1, 127, 2, 0, 0, 0},
{ 0, 1, -3, 127, 4, -2, 1, 0}, { 0, 1, -5, 127, 6, -2, 1, 0},
{ 0, 2, -6, 126, 8, -3, 1, 0}, {-1, 2, -7, 126, 11, -4, 2, -1},
{-1, 3, -8, 125, 13, -5, 2, -1}, {-1, 3, -10, 124, 16, -6, 3, -1},
{-1, 4, -11, 123, 18, -7, 3, -1}, {-1, 4, -12, 122, 20, -7, 3, -1},
{-1, 4, -13, 121, 23, -8, 3, -1}, {-2, 5, -14, 120, 25, -9, 4, -1},
{-1, 5, -15, 119, 27, -10, 4, -1}, {-1, 5, -16, 118, 30, -11, 4, -1},
{-2, 6, -17, 116, 33, -12, 5, -1}, {-2, 6, -17, 114, 35, -12, 5, -1},
{-2, 6, -18, 113, 38, -13, 5, -1}, {-2, 7, -19, 111, 41, -14, 6, -2},
{-2, 7, -19, 110, 43, -15, 6, -2}, {-2, 7, -20, 108, 46, -15, 6, -2},
{-2, 7, -20, 106, 49, -16, 6, -2}, {-2, 7, -21, 104, 51, -16, 7, -2},
{-2, 7, -21, 102, 54, -17, 7, -2}, {-2, 8, -21, 100, 56, -18, 7, -2},
{-2, 8, -22, 98, 59, -18, 7, -2}, {-2, 8, -22, 96, 62, -19, 7, -2},
{-2, 8, -22, 94, 64, -19, 7, -2}, {-2, 8, -22, 91, 67, -20, 8, -2},
{-2, 8, -22, 89, 69, -20, 8, -2}, {-2, 8, -22, 87, 72, -21, 8, -2},
{-2, 8, -21, 84, 74, -21, 8, -2}, {-2, 8, -22, 82, 77, -21, 8, -2},
{-2, 8, -21, 79, 79, -21, 8, -2}, {-2, 8, -21, 77, 82, -22, 8, -2},
{-2, 8, -21, 74, 84, -21, 8, -2}, {-2, 8, -21, 72, 87, -22, 8, -2},
{-2, 8, -20, 69, 89, -22, 8, -2}, {-2, 8, -20, 67, 91, -22, 8, -2},
{-2, 7, -19, 64, 94, -22, 8, -2}, {-2, 7, -19, 62, 96, -22, 8, -2},
{-2, 7, -18, 59, 98, -22, 8, -2}, {-2, 7, -18, 56, 100, -21, 8, -2},
{-2, 7, -17, 54, 102, -21, 7, -2}, {-2, 7, -16, 51, 104, -21, 7, -2},
{-2, 6, -16, 49, 106, -20, 7, -2}, {-2, 6, -15, 46, 108, -20, 7, -2},
{-2, 6, -15, 43, 110, -19, 7, -2}, {-2, 6, -14, 41, 111, -19, 7, -2},
{-1, 5, -13, 38, 113, -18, 6, -2}, {-1, 5, -12, 35, 114, -17, 6, -2},
{-1, 5, -12, 33, 116, -17, 6, -2}, {-1, 4, -11, 30, 118, -16, 5, -1},
{-1, 4, -10, 27, 119, -15, 5, -1}, {-1, 4, -9, 25, 120, -14, 5, -2},
{-1, 3, -8, 23, 121, -13, 4, -1}, {-1, 3, -7, 20, 122, -12, 4, -1},
{-1, 3, -7, 18, 123, -11, 4, -1}, {-1, 3, -6, 16, 124, -10, 3, -1},
{-1, 2, -5, 13, 125, -8, 3, -1}, {-1, 2, -4, 11, 126, -7, 2, -1},
{ 0, 1, -3, 8, 126, -6, 2, 0}, { 0, 1, -2, 6, 127, -5, 1, 0},
{ 0, 1, -2, 4, 127, -3, 1, 0}, { 0, 0, 0, 2, 127, -1, 0, 0},
// [1, 2)
{ 0, 0, 0, 1, 127, 0, 0, 0 }, { 0, 0, 0, - 1, 127, 2, 0, 0 },
{ 0, 0, 1, - 3, 127, 4, - 1, 0 }, { 0, 0, 1, - 4, 126, 6, - 2, 1 },
{ 0, 0, 1, - 5, 126, 8, - 3, 1 }, { 0, 0, 1, - 6, 125, 11, - 4, 1 },
{ 0, 0, 1, - 7, 124, 13, - 4, 1 }, { 0, 0, 2, - 8, 123, 15, - 5, 1 },
{ 0, 0, 2, - 9, 122, 18, - 6, 1 }, { 0, 0, 2, -10, 121, 20, - 6, 1 },
{ 0, 0, 2, -11, 120, 22, - 7, 2 }, { 0, 0, 2, -12, 119, 25, - 8, 2 },
{ 0, 0, 3, -13, 117, 27, - 8, 2 }, { 0, 0, 3, -13, 116, 29, - 9, 2 },
{ 0, 0, 3, -14, 114, 32, -10, 3 }, { 0, 0, 3, -15, 113, 35, -10, 2 },
{ 0, 0, 3, -15, 111, 37, -11, 3 }, { 0, 0, 3, -16, 109, 40, -11, 3 },
{ 0, 0, 3, -16, 108, 42, -12, 3 }, { 0, 0, 4, -17, 106, 45, -13, 3 },
{ 0, 0, 4, -17, 104, 47, -13, 3 }, { 0, 0, 4, -17, 102, 50, -14, 3 },
{ 0, 0, 4, -17, 100, 52, -14, 3 }, { 0, 0, 4, -18, 98, 55, -15, 4 },
{ 0, 0, 4, -18, 96, 58, -15, 3 }, { 0, 0, 4, -18, 94, 60, -16, 4 },
{ 0, 0, 4, -18, 91, 63, -16, 4 }, { 0, 0, 4, -18, 89, 65, -16, 4 },
{ 0, 0, 4, -18, 87, 68, -17, 4 }, { 0, 0, 4, -18, 85, 70, -17, 4 },
{ 0, 0, 4, -18, 82, 73, -17, 4 }, { 0, 0, 4, -18, 80, 75, -17, 4 },
{ 0, 0, 4, -18, 78, 78, -18, 4 }, { 0, 0, 4, -17, 75, 80, -18, 4 },
{ 0, 0, 4, -17, 73, 82, -18, 4 }, { 0, 0, 4, -17, 70, 85, -18, 4 },
{ 0, 0, 4, -17, 68, 87, -18, 4 }, { 0, 0, 4, -16, 65, 89, -18, 4 },
{ 0, 0, 4, -16, 63, 91, -18, 4 }, { 0, 0, 4, -16, 60, 94, -18, 4 },
{ 0, 0, 3, -15, 58, 96, -18, 4 }, { 0, 0, 4, -15, 55, 98, -18, 4 },
{ 0, 0, 3, -14, 52, 100, -17, 4 }, { 0, 0, 3, -14, 50, 102, -17, 4 },
{ 0, 0, 3, -13, 47, 104, -17, 4 }, { 0, 0, 3, -13, 45, 106, -17, 4 },
{ 0, 0, 3, -12, 42, 108, -16, 3 }, { 0, 0, 3, -11, 40, 109, -16, 3 },
{ 0, 0, 3, -11, 37, 111, -15, 3 }, { 0, 0, 2, -10, 35, 113, -15, 3 },
{ 0, 0, 3, -10, 32, 114, -14, 3 }, { 0, 0, 2, - 9, 29, 116, -13, 3 },
{ 0, 0, 2, - 8, 27, 117, -13, 3 }, { 0, 0, 2, - 8, 25, 119, -12, 2 },
{ 0, 0, 2, - 7, 22, 120, -11, 2 }, { 0, 0, 1, - 6, 20, 121, -10, 2 },
{ 0, 0, 1, - 6, 18, 122, - 9, 2 }, { 0, 0, 1, - 5, 15, 123, - 8, 2 },
{ 0, 0, 1, - 4, 13, 124, - 7, 1 }, { 0, 0, 1, - 4, 11, 125, - 6, 1 },
{ 0, 0, 1, - 3, 8, 126, - 5, 1 }, { 0, 0, 1, - 2, 6, 126, - 4, 1 },
{ 0, 0, 0, - 1, 4, 127, - 3, 1 }, { 0, 0, 0, 0, 2, 127, - 1, 0 },
// dummy (replicate row index 191)
{ 0, 0, 0, 0, 2, 127, - 1, 0 },
};
/* clang-format on */
#define DIV_LUT_PREC_BITS 14
#define DIV_LUT_BITS 8
#define DIV_LUT_NUM (1 << DIV_LUT_BITS)
static const uint16_t div_lut[DIV_LUT_NUM + 1] = {
16384, 16320, 16257, 16194, 16132, 16070, 16009, 15948, 15888, 15828, 15768,
15709, 15650, 15592, 15534, 15477, 15420, 15364, 15308, 15252, 15197, 15142,
15087, 15033, 14980, 14926, 14873, 14821, 14769, 14717, 14665, 14614, 14564,
14513, 14463, 14413, 14364, 14315, 14266, 14218, 14170, 14122, 14075, 14028,
13981, 13935, 13888, 13843, 13797, 13752, 13707, 13662, 13618, 13574, 13530,
13487, 13443, 13400, 13358, 13315, 13273, 13231, 13190, 13148, 13107, 13066,
13026, 12985, 12945, 12906, 12866, 12827, 12788, 12749, 12710, 12672, 12633,
12596, 12558, 12520, 12483, 12446, 12409, 12373, 12336, 12300, 12264, 12228,
12193, 12157, 12122, 12087, 12053, 12018, 11984, 11950, 11916, 11882, 11848,
11815, 11782, 11749, 11716, 11683, 11651, 11619, 11586, 11555, 11523, 11491,
11460, 11429, 11398, 11367, 11336, 11305, 11275, 11245, 11215, 11185, 11155,
11125, 11096, 11067, 11038, 11009, 10980, 10951, 10923, 10894, 10866, 10838,
10810, 10782, 10755, 10727, 10700, 10673, 10645, 10618, 10592, 10565, 10538,
10512, 10486, 10460, 10434, 10408, 10382, 10356, 10331, 10305, 10280, 10255,
10230, 10205, 10180, 10156, 10131, 10107, 10082, 10058, 10034, 10010, 9986,
9963, 9939, 9916, 9892, 9869, 9846, 9823, 9800, 9777, 9754, 9732,
9709, 9687, 9664, 9642, 9620, 9598, 9576, 9554, 9533, 9511, 9489,
9468, 9447, 9425, 9404, 9383, 9362, 9341, 9321, 9300, 9279, 9259,
9239, 9218, 9198, 9178, 9158, 9138, 9118, 9098, 9079, 9059, 9039,
9020, 9001, 8981, 8962, 8943, 8924, 8905, 8886, 8867, 8849, 8830,
8812, 8793, 8775, 8756, 8738, 8720, 8702, 8684, 8666, 8648, 8630,
8613, 8595, 8577, 8560, 8542, 8525, 8508, 8490, 8473, 8456, 8439,
8422, 8405, 8389, 8372, 8355, 8339, 8322, 8306, 8289, 8273, 8257,
8240, 8224, 8208, 8192,
};
// Decomposes a divisor D such that 1/D = y/2^shift, where y is returned
// at precision of DIV_LUT_PREC_BITS along with the shift.
static int16_t resolve_divisor_64(uint64_t D, int16_t *shift) {
int64_t f;
*shift = (int16_t)((D >> 32) ? get_msb((unsigned int)(D >> 32)) + 32
: get_msb((unsigned int)D));
// e is obtained from D after resetting the most significant 1 bit.
const int64_t e = D - ((uint64_t)1 << *shift);
// Get the most significant DIV_LUT_BITS (8) bits of e into f
if (*shift > DIV_LUT_BITS)
f = ROUND_POWER_OF_TWO_64(e, *shift - DIV_LUT_BITS);
else
f = e << (DIV_LUT_BITS - *shift);
assert(f <= DIV_LUT_NUM);
*shift += DIV_LUT_PREC_BITS;
// Use f as lookup into the precomputed table of multipliers
return div_lut[f];
}
static int16_t resolve_divisor_32(uint32_t D, int16_t *shift) {
int32_t f;
*shift = get_msb(D);
// e is obtained from D after resetting the most significant 1 bit.
const int32_t e = D - ((uint32_t)1 << *shift);
// Get the most significant DIV_LUT_BITS (8) bits of e into f
if (*shift > DIV_LUT_BITS)
f = ROUND_POWER_OF_TWO(e, *shift - DIV_LUT_BITS);
else
f = e << (DIV_LUT_BITS - *shift);
assert(f <= DIV_LUT_NUM);
*shift += DIV_LUT_PREC_BITS;
// Use f as lookup into the precomputed table of multipliers
return div_lut[f];
}
static int is_affine_valid(const WarpedMotionParams *const wm) {
const int32_t *mat = wm->wmmat;
return (mat[2] > 0);
}
static int is_affine_shear_allowed(int16_t alpha, int16_t beta, int16_t gamma,
int16_t delta) {
if ((4 * abs(alpha) + 7 * abs(beta) >= (1 << WARPEDMODEL_PREC_BITS)) ||
(4 * abs(gamma) + 4 * abs(delta) >= (1 << WARPEDMODEL_PREC_BITS)))
return 0;
else
return 1;
}
#ifndef NDEBUG
// Check that the given warp model satisfies the relevant constraints for
// its stated model type
static void check_model_consistency(WarpedMotionParams *wm) {
switch (wm->wmtype) {
case IDENTITY:
assert(wm->wmmat[0] == 0);
assert(wm->wmmat[1] == 0);
AOM_FALLTHROUGH_INTENDED;
case TRANSLATION:
assert(wm->wmmat[2] == 1 << WARPEDMODEL_PREC_BITS);
assert(wm->wmmat[3] == 0);
AOM_FALLTHROUGH_INTENDED;
case ROTZOOM:
assert(wm->wmmat[4] == -wm->wmmat[3]);
assert(wm->wmmat[5] == wm->wmmat[2]);
AOM_FALLTHROUGH_INTENDED;
case AFFINE: break;
default: assert(0 && "Bad wmtype");
}
}
#endif // NDEBUG
// Returns 1 on success or 0 on an invalid affine set
int av1_get_shear_params(WarpedMotionParams *wm) {
#ifndef NDEBUG
// Check that models have been constructed sensibly
// This is a good place to check, because this function does not need to
// be called until after model construction is complete, but must be called
// before the model can be used for prediction.
check_model_consistency(wm);
#endif // NDEBUG
const int32_t *mat = wm->wmmat;
if (!is_affine_valid(wm)) return 0;
wm->alpha =
clamp(mat[2] - (1 << WARPEDMODEL_PREC_BITS), INT16_MIN, INT16_MAX);
wm->beta = clamp(mat[3], INT16_MIN, INT16_MAX);
int16_t shift;
int16_t y = resolve_divisor_32(abs(mat[2]), &shift) * (mat[2] < 0 ? -1 : 1);
int64_t v = ((int64_t)mat[4] * (1 << WARPEDMODEL_PREC_BITS)) * y;
wm->gamma =
clamp((int)ROUND_POWER_OF_TWO_SIGNED_64(v, shift), INT16_MIN, INT16_MAX);
v = ((int64_t)mat[3] * mat[4]) * y;
wm->delta = clamp(mat[5] - (int)ROUND_POWER_OF_TWO_SIGNED_64(v, shift) -
(1 << WARPEDMODEL_PREC_BITS),
INT16_MIN, INT16_MAX);
wm->alpha = ROUND_POWER_OF_TWO_SIGNED(wm->alpha, WARP_PARAM_REDUCE_BITS) *
(1 << WARP_PARAM_REDUCE_BITS);
wm->beta = ROUND_POWER_OF_TWO_SIGNED(wm->beta, WARP_PARAM_REDUCE_BITS) *
(1 << WARP_PARAM_REDUCE_BITS);
wm->gamma = ROUND_POWER_OF_TWO_SIGNED(wm->gamma, WARP_PARAM_REDUCE_BITS) *
(1 << WARP_PARAM_REDUCE_BITS);
wm->delta = ROUND_POWER_OF_TWO_SIGNED(wm->delta, WARP_PARAM_REDUCE_BITS) *
(1 << WARP_PARAM_REDUCE_BITS);
if (!is_affine_shear_allowed(wm->alpha, wm->beta, wm->gamma, wm->delta))
return 0;
return 1;
}
#if CONFIG_AV1_HIGHBITDEPTH
/* Note: For an explanation of the warp algorithm, and some notes on bit widths
for hardware implementations, see the comments above av1_warp_affine_c
*/
void av1_highbd_warp_affine_c(const int32_t *mat, const uint16_t *ref,
int width, int height, int stride, uint16_t *pred,
int p_col, int p_row, int p_width, int p_height,
int p_stride, int subsampling_x,
int subsampling_y, int bd,
ConvolveParams *conv_params, int16_t alpha,
int16_t beta, int16_t gamma, int16_t delta) {
int32_t tmp[15 * 8];
const int reduce_bits_horiz = conv_params->round_0;
const int reduce_bits_vert = conv_params->is_compound
? conv_params->round_1
: 2 * FILTER_BITS - reduce_bits_horiz;
const int max_bits_horiz = bd + FILTER_BITS + 1 - reduce_bits_horiz;
const int offset_bits_horiz = bd + FILTER_BITS - 1;
const int offset_bits_vert = bd + 2 * FILTER_BITS - reduce_bits_horiz;
const int round_bits =
2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
const int offset_bits = bd + 2 * FILTER_BITS - conv_params->round_0;
(void)max_bits_horiz;
assert(IMPLIES(conv_params->is_compound, conv_params->dst != NULL));
// Check that, even with 12-bit input, the intermediate values will fit
// into an unsigned 16-bit intermediate array.
assert(bd + FILTER_BITS + 2 - conv_params->round_0 <= 16);
for (int i = p_row; i < p_row + p_height; i += 8) {
for (int j = p_col; j < p_col + p_width; j += 8) {
// Calculate the center of this 8x8 block,
// project to luma coordinates (if in a subsampled chroma plane),
// apply the affine transformation,
// then convert back to the original coordinates (if necessary)
const int32_t src_x = (j + 4) << subsampling_x;
const int32_t src_y = (i + 4) << subsampling_y;
const int64_t dst_x =
(int64_t)mat[2] * src_x + (int64_t)mat[3] * src_y + (int64_t)mat[0];
const int64_t dst_y =
(int64_t)mat[4] * src_x + (int64_t)mat[5] * src_y + (int64_t)mat[1];
const int64_t x4 = dst_x >> subsampling_x;
const int64_t y4 = dst_y >> subsampling_y;
const int32_t ix4 = (int32_t)(x4 >> WARPEDMODEL_PREC_BITS);
int32_t sx4 = x4 & ((1 << WARPEDMODEL_PREC_BITS) - 1);
const int32_t iy4 = (int32_t)(y4 >> WARPEDMODEL_PREC_BITS);
int32_t sy4 = y4 & ((1 << WARPEDMODEL_PREC_BITS) - 1);
sx4 += alpha * (-4) + beta * (-4);
sy4 += gamma * (-4) + delta * (-4);
sx4 &= ~((1 << WARP_PARAM_REDUCE_BITS) - 1);
sy4 &= ~((1 << WARP_PARAM_REDUCE_BITS) - 1);
// Horizontal filter
for (int k = -7; k < 8; ++k) {
const int iy = clamp(iy4 + k, 0, height - 1);
int sx = sx4 + beta * (k + 4);
for (int l = -4; l < 4; ++l) {
int ix = ix4 + l - 3;
const int offs = ROUND_POWER_OF_TWO(sx, WARPEDDIFF_PREC_BITS) +
WARPEDPIXEL_PREC_SHIFTS;
assert(offs >= 0 && offs <= WARPEDPIXEL_PREC_SHIFTS * 3);
const int16_t *coeffs = av1_warped_filter[offs];
int32_t sum = 1 << offset_bits_horiz;
for (int m = 0; m < 8; ++m) {
const int sample_x = clamp(ix + m, 0, width - 1);
sum += ref[iy * stride + sample_x] * coeffs[m];
}
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_horiz);
assert(0 <= sum && sum < (1 << max_bits_horiz));
tmp[(k + 7) * 8 + (l + 4)] = sum;
sx += alpha;
}
}
// Vertical filter
for (int k = -4; k < AOMMIN(4, p_row + p_height - i - 4); ++k) {
int sy = sy4 + delta * (k + 4);
for (int l = -4; l < AOMMIN(4, p_col + p_width - j - 4); ++l) {
const int offs = ROUND_POWER_OF_TWO(sy, WARPEDDIFF_PREC_BITS) +
WARPEDPIXEL_PREC_SHIFTS;
assert(offs >= 0 && offs <= WARPEDPIXEL_PREC_SHIFTS * 3);
const int16_t *coeffs = av1_warped_filter[offs];
int32_t sum = 1 << offset_bits_vert;
for (int m = 0; m < 8; ++m) {
sum += tmp[(k + m + 4) * 8 + (l + 4)] * coeffs[m];
}
if (conv_params->is_compound) {
CONV_BUF_TYPE *p =
&conv_params
->dst[(i - p_row + k + 4) * conv_params->dst_stride +
(j - p_col + l + 4)];
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_vert);
if (conv_params->do_average) {
uint16_t *dst16 =
&pred[(i - p_row + k + 4) * p_stride + (j - p_col + l + 4)];
int32_t tmp32 = *p;
if (conv_params->use_dist_wtd_comp_avg) {
tmp32 = tmp32 * conv_params->fwd_offset +
sum * conv_params->bck_offset;
tmp32 = tmp32 >> DIST_PRECISION_BITS;
} else {
tmp32 += sum;
tmp32 = tmp32 >> 1;
}
tmp32 = tmp32 - (1 << (offset_bits - conv_params->round_1)) -
(1 << (offset_bits - conv_params->round_1 - 1));
*dst16 =
clip_pixel_highbd(ROUND_POWER_OF_TWO(tmp32, round_bits), bd);
} else {
*p = sum;
}
} else {
uint16_t *p =
&pred[(i - p_row + k + 4) * p_stride + (j - p_col + l + 4)];
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_vert);
assert(0 <= sum && sum < (1 << (bd + 2)));
*p = clip_pixel_highbd(sum - (1 << (bd - 1)) - (1 << bd), bd);
}
sy += gamma;
}
}
}
}
}
void highbd_warp_plane(WarpedMotionParams *wm, const uint16_t *const ref,
int width, int height, int stride, uint16_t *const pred,
int p_col, int p_row, int p_width, int p_height,
int p_stride, int subsampling_x, int subsampling_y,
int bd, ConvolveParams *conv_params) {
const int32_t *const mat = wm->wmmat;
const int16_t alpha = wm->alpha;
const int16_t beta = wm->beta;
const int16_t gamma = wm->gamma;
const int16_t delta = wm->delta;
av1_highbd_warp_affine(mat, ref, width, height, stride, pred, p_col, p_row,
p_width, p_height, p_stride, subsampling_x,
subsampling_y, bd, conv_params, alpha, beta, gamma,
delta);
}
#endif // CONFIG_AV1_HIGHBITDEPTH
/* The warp filter for ROTZOOM and AFFINE models works as follows:
* Split the input into 8x8 blocks
* For each block, project the point (4, 4) within the block, to get the
overall block position. Split into integer and fractional coordinates,
maintaining full WARPEDMODEL precision
* Filter horizontally: Generate 15 rows of 8 pixels each. Each pixel gets a
variable horizontal offset. This means that, while the rows of the
intermediate buffer align with the rows of the *reference* image, the
columns align with the columns of the *destination* image.
* Filter vertically: Generate the output block (up to 8x8 pixels, but if the
destination is too small we crop the output at this stage). Each pixel has
a variable vertical offset, so that the resulting rows are aligned with
the rows of the destination image.
To accomplish these alignments, we factor the warp matrix as a
product of two shear / asymmetric zoom matrices:
/ a b \ = / 1 0 \ * / 1+alpha beta \
\ c d / \ gamma 1+delta / \ 0 1 /
where a, b, c, d are wmmat[2], wmmat[3], wmmat[4], wmmat[5] respectively.
The horizontal shear (with alpha and beta) is applied first,
then the vertical shear (with gamma and delta) is applied second.
The only limitation is that, to fit this in a fixed 8-tap filter size,
the fractional pixel offsets must be at most +-1. Since the horizontal filter
generates 15 rows of 8 columns, and the initial point we project is at (4, 4)
within the block, the parameters must satisfy
4 * |alpha| + 7 * |beta| <= 1 and 4 * |gamma| + 4 * |delta| <= 1
for this filter to be applicable.
Note: This function assumes that the caller has done all of the relevant
checks, ie. that we have a ROTZOOM or AFFINE model, that wm[4] and wm[5]
are set appropriately (if using a ROTZOOM model), and that alpha, beta,
gamma, delta are all in range.
TODO(rachelbarker): Maybe support scaled references?
*/
/* A note on hardware implementation:
The warp filter is intended to be implementable using the same hardware as
the high-precision convolve filters from the loop-restoration and
convolve-round experiments.
For a single filter stage, considering all of the coefficient sets for the
warp filter and the regular convolution filter, an input in the range
[0, 2^k - 1] is mapped into the range [-56 * (2^k - 1), 184 * (2^k - 1)]
before rounding.
Allowing for some changes to the filter coefficient sets, call the range
[-64 * 2^k, 192 * 2^k]. Then, if we initialize the accumulator to 64 * 2^k,
we can replace this by the range [0, 256 * 2^k], which can be stored in an
unsigned value with 8 + k bits.
This allows the derivation of the appropriate bit widths and offsets for
the various intermediate values: If
F := FILTER_BITS = 7 (or else the above ranges need adjusting)
So a *single* filter stage maps a k-bit input to a (k + F + 1)-bit
intermediate value.
H := ROUND0_BITS
V := VERSHEAR_REDUCE_PREC_BITS
(and note that we must have H + V = 2*F for the output to have the same
scale as the input)
then we end up with the following offsets and ranges:
Horizontal filter: Apply an offset of 1 << (bd + F - 1), sum fits into a
uint{bd + F + 1}
After rounding: The values stored in 'tmp' fit into a uint{bd + F + 1 - H}.
Vertical filter: Apply an offset of 1 << (bd + 2*F - H), sum fits into a
uint{bd + 2*F + 2 - H}
After rounding: The final value, before undoing the offset, fits into a
uint{bd + 2}.
Then we need to undo the offsets before clamping to a pixel. Note that,
if we do this at the end, the amount to subtract is actually independent
of H and V:
offset to subtract = (1 << ((bd + F - 1) - H + F - V)) +
(1 << ((bd + 2*F - H) - V))
== (1 << (bd - 1)) + (1 << bd)
This allows us to entirely avoid clamping in both the warp filter and
the convolve-round experiment. As of the time of writing, the Wiener filter
from loop-restoration can encode a central coefficient up to 216, which
leads to a maximum value of about 282 * 2^k after applying the offset.
So in that case we still need to clamp.
*/
void av1_warp_affine_c(const int32_t *mat, const uint8_t *ref, int width,
int height, int stride, uint8_t *pred, int p_col,
int p_row, int p_width, int p_height, int p_stride,
int subsampling_x, int subsampling_y,
ConvolveParams *conv_params, int16_t alpha, int16_t beta,
int16_t gamma, int16_t delta) {
int32_t tmp[15 * 8];
const int bd = 8;
const int reduce_bits_horiz = conv_params->round_0;
const int reduce_bits_vert = conv_params->is_compound
? conv_params->round_1
: 2 * FILTER_BITS - reduce_bits_horiz;
const int max_bits_horiz = bd + FILTER_BITS + 1 - reduce_bits_horiz;
const int offset_bits_horiz = bd + FILTER_BITS - 1;
const int offset_bits_vert = bd + 2 * FILTER_BITS - reduce_bits_horiz;
const int round_bits =
2 * FILTER_BITS - conv_params->round_0 - conv_params->round_1;
const int offset_bits = bd + 2 * FILTER_BITS - conv_params->round_0;
(void)max_bits_horiz;
assert(IMPLIES(conv_params->is_compound, conv_params->dst != NULL));
assert(IMPLIES(conv_params->do_average, conv_params->is_compound));
for (int i = p_row; i < p_row + p_height; i += 8) {
for (int j = p_col; j < p_col + p_width; j += 8) {
// Calculate the center of this 8x8 block,
// project to luma coordinates (if in a subsampled chroma plane),
// apply the affine transformation,
// then convert back to the original coordinates (if necessary)
const int32_t src_x = (j + 4) << subsampling_x;
const int32_t src_y = (i + 4) << subsampling_y;
const int64_t dst_x =
(int64_t)mat[2] * src_x + (int64_t)mat[3] * src_y + (int64_t)mat[0];
const int64_t dst_y =
(int64_t)mat[4] * src_x + (int64_t)mat[5] * src_y + (int64_t)mat[1];
const int64_t x4 = dst_x >> subsampling_x;
const int64_t y4 = dst_y >> subsampling_y;
int32_t ix4 = (int32_t)(x4 >> WARPEDMODEL_PREC_BITS);
int32_t sx4 = x4 & ((1 << WARPEDMODEL_PREC_BITS) - 1);
int32_t iy4 = (int32_t)(y4 >> WARPEDMODEL_PREC_BITS);
int32_t sy4 = y4 & ((1 << WARPEDMODEL_PREC_BITS) - 1);
sx4 += alpha * (-4) + beta * (-4);
sy4 += gamma * (-4) + delta * (-4);
sx4 &= ~((1 << WARP_PARAM_REDUCE_BITS) - 1);
sy4 &= ~((1 << WARP_PARAM_REDUCE_BITS) - 1);
// Horizontal filter
for (int k = -7; k < 8; ++k) {
// Clamp to top/bottom edge of the frame
const int iy = clamp(iy4 + k, 0, height - 1);
int sx = sx4 + beta * (k + 4);
for (int l = -4; l < 4; ++l) {
int ix = ix4 + l - 3;
// At this point, sx = sx4 + alpha * l + beta * k
const int offs = ROUND_POWER_OF_TWO(sx, WARPEDDIFF_PREC_BITS) +
WARPEDPIXEL_PREC_SHIFTS;
assert(offs >= 0 && offs <= WARPEDPIXEL_PREC_SHIFTS * 3);
const int16_t *coeffs = av1_warped_filter[offs];
int32_t sum = 1 << offset_bits_horiz;
for (int m = 0; m < 8; ++m) {
// Clamp to left/right edge of the frame
const int sample_x = clamp(ix + m, 0, width - 1);
sum += ref[iy * stride + sample_x] * coeffs[m];
}
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_horiz);
assert(0 <= sum && sum < (1 << max_bits_horiz));
tmp[(k + 7) * 8 + (l + 4)] = sum;
sx += alpha;
}
}
// Vertical filter
for (int k = -4; k < AOMMIN(4, p_row + p_height - i - 4); ++k) {
int sy = sy4 + delta * (k + 4);
for (int l = -4; l < AOMMIN(4, p_col + p_width - j - 4); ++l) {
// At this point, sy = sy4 + gamma * l + delta * k
const int offs = ROUND_POWER_OF_TWO(sy, WARPEDDIFF_PREC_BITS) +
WARPEDPIXEL_PREC_SHIFTS;
assert(offs >= 0 && offs <= WARPEDPIXEL_PREC_SHIFTS * 3);
const int16_t *coeffs = av1_warped_filter[offs];
int32_t sum = 1 << offset_bits_vert;
for (int m = 0; m < 8; ++m) {
sum += tmp[(k + m + 4) * 8 + (l + 4)] * coeffs[m];
}
if (conv_params->is_compound) {
CONV_BUF_TYPE *p =
&conv_params
->dst[(i - p_row + k + 4) * conv_params->dst_stride +
(j - p_col + l + 4)];
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_vert);
if (conv_params->do_average) {
uint8_t *dst8 =
&pred[(i - p_row + k + 4) * p_stride + (j - p_col + l + 4)];
int32_t tmp32 = *p;
if (conv_params->use_dist_wtd_comp_avg) {
tmp32 = tmp32 * conv_params->fwd_offset +
sum * conv_params->bck_offset;
tmp32 = tmp32 >> DIST_PRECISION_BITS;
} else {
tmp32 += sum;
tmp32 = tmp32 >> 1;
}
tmp32 = tmp32 - (1 << (offset_bits - conv_params->round_1)) -
(1 << (offset_bits - conv_params->round_1 - 1));
*dst8 = clip_pixel(ROUND_POWER_OF_TWO(tmp32, round_bits));
} else {
*p = sum;
}
} else {
uint8_t *p =
&pred[(i - p_row + k + 4) * p_stride + (j - p_col + l + 4)];
sum = ROUND_POWER_OF_TWO(sum, reduce_bits_vert);
assert(0 <= sum && sum < (1 << (bd + 2)));
*p = clip_pixel(sum - (1 << (bd - 1)) - (1 << bd));
}
sy += gamma;
}
}
}
}
}
void warp_plane(WarpedMotionParams *wm, const uint8_t *const ref, int width,
int height, int stride, uint8_t *pred, int p_col, int p_row,
int p_width, int p_height, int p_stride, int subsampling_x,
int subsampling_y, ConvolveParams *conv_params) {
const int32_t *const mat = wm->wmmat;
const int16_t alpha = wm->alpha;
const int16_t beta = wm->beta;
const int16_t gamma = wm->gamma;
const int16_t delta = wm->delta;
av1_warp_affine(mat, ref, width, height, stride, pred, p_col, p_row, p_width,
p_height, p_stride, subsampling_x, subsampling_y, conv_params,
alpha, beta, gamma, delta);
}
void av1_warp_plane(WarpedMotionParams *wm, int use_hbd, int bd,
const uint8_t *ref, int width, int height, int stride,
uint8_t *pred, int p_col, int p_row, int p_width,
int p_height, int p_stride, int subsampling_x,
int subsampling_y, ConvolveParams *conv_params) {
#if CONFIG_AV1_HIGHBITDEPTH
if (use_hbd)
highbd_warp_plane(wm, CONVERT_TO_SHORTPTR(ref), width, height, stride,
CONVERT_TO_SHORTPTR(pred), p_col, p_row, p_width,
p_height, p_stride, subsampling_x, subsampling_y, bd,
conv_params);
else
warp_plane(wm, ref, width, height, stride, pred, p_col, p_row, p_width,
p_height, p_stride, subsampling_x, subsampling_y, conv_params);
#else
(void)use_hbd;
(void)bd;
warp_plane(wm, ref, width, height, stride, pred, p_col, p_row, p_width,
p_height, p_stride, subsampling_x, subsampling_y, conv_params);
#endif
}
#define LS_MV_MAX 256 // max mv in 1/8-pel
// Use LS_STEP = 8 so that 2 less bits needed for A, Bx, By.
#define LS_STEP 8
// Assuming LS_MV_MAX is < MAX_SB_SIZE * 8,
// the precision needed is:
// (MAX_SB_SIZE_LOG2 + 3) [for sx * sx magnitude] +
// (MAX_SB_SIZE_LOG2 + 4) [for sx * dx magnitude] +
// 1 [for sign] +
// LEAST_SQUARES_SAMPLES_MAX_BITS
// [for adding up to LEAST_SQUARES_SAMPLES_MAX samples]
// The value is 23
#define LS_MAT_RANGE_BITS \
((MAX_SB_SIZE_LOG2 + 4) * 2 + LEAST_SQUARES_SAMPLES_MAX_BITS)
// Bit-depth reduction from the full-range
#define LS_MAT_DOWN_BITS 2
// bits range of A, Bx and By after downshifting
#define LS_MAT_BITS (LS_MAT_RANGE_BITS - LS_MAT_DOWN_BITS)
#define LS_MAT_MIN (-(1 << (LS_MAT_BITS - 1)))
#define LS_MAT_MAX ((1 << (LS_MAT_BITS - 1)) - 1)
// By setting LS_STEP = 8, the least 2 bits of every elements in A, Bx, By are
// 0. So, we can reduce LS_MAT_RANGE_BITS(2) bits here.
#define LS_SQUARE(a) \
(((a) * (a)*4 + (a)*4 * LS_STEP + LS_STEP * LS_STEP * 2) >> \
(2 + LS_MAT_DOWN_BITS))
#define LS_PRODUCT1(a, b) \
(((a) * (b)*4 + ((a) + (b)) * 2 * LS_STEP + LS_STEP * LS_STEP) >> \
(2 + LS_MAT_DOWN_BITS))
#define LS_PRODUCT2(a, b) \
(((a) * (b)*4 + ((a) + (b)) * 2 * LS_STEP + LS_STEP * LS_STEP * 2) >> \
(2 + LS_MAT_DOWN_BITS))
#define USE_LIMITED_PREC_MULT 0
#if USE_LIMITED_PREC_MULT
#define MUL_PREC_BITS 16
static uint16_t resolve_multiplier_64(uint64_t D, int16_t *shift) {
int msb = 0;
uint16_t mult = 0;
*shift = 0;
if (D != 0) {
msb = (int16_t)((D >> 32) ? get_msb((unsigned int)(D >> 32)) + 32
: get_msb((unsigned int)D));
if (msb >= MUL_PREC_BITS) {
mult = (uint16_t)ROUND_POWER_OF_TWO_64(D, msb + 1 - MUL_PREC_BITS);
*shift = msb + 1 - MUL_PREC_BITS;
} else {
mult = (uint16_t)D;
*shift = 0;
}
}
return mult;
}
static int32_t get_mult_shift_ndiag(int64_t Px, int16_t iDet, int shift) {
int32_t ret;
int16_t mshift;
uint16_t Mul = resolve_multiplier_64(llabs(Px), &mshift);
int32_t v = (int32_t)Mul * (int32_t)iDet * (Px < 0 ? -1 : 1);
shift -= mshift;
if (shift > 0) {
return (int32_t)clamp(ROUND_POWER_OF_TWO_SIGNED(v, shift),
-WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
} else {
return (int32_t)clamp(v * (1 << (-shift)),
-WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
}
return ret;
}
static int32_t get_mult_shift_diag(int64_t Px, int16_t iDet, int shift) {
int16_t mshift;
uint16_t Mul = resolve_multiplier_64(llabs(Px), &mshift);
int32_t v = (int32_t)Mul * (int32_t)iDet * (Px < 0 ? -1 : 1);
shift -= mshift;
if (shift > 0) {
return (int32_t)clamp(
ROUND_POWER_OF_TWO_SIGNED(v, shift),
(1 << WARPEDMODEL_PREC_BITS) - WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
(1 << WARPEDMODEL_PREC_BITS) + WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
} else {
return (int32_t)clamp(
v * (1 << (-shift)),
(1 << WARPEDMODEL_PREC_BITS) - WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
(1 << WARPEDMODEL_PREC_BITS) + WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
}
}
#else
static int32_t get_mult_shift_ndiag(int64_t Px, int16_t iDet, int shift) {
int64_t v = Px * (int64_t)iDet;
return (int32_t)clamp64(ROUND_POWER_OF_TWO_SIGNED_64(v, shift),
-WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
}
static int32_t get_mult_shift_diag(int64_t Px, int16_t iDet, int shift) {
int64_t v = Px * (int64_t)iDet;
return (int32_t)clamp64(
ROUND_POWER_OF_TWO_SIGNED_64(v, shift),
(1 << WARPEDMODEL_PREC_BITS) - WARPEDMODEL_NONDIAGAFFINE_CLAMP + 1,
(1 << WARPEDMODEL_PREC_BITS) + WARPEDMODEL_NONDIAGAFFINE_CLAMP - 1);
}
#endif // USE_LIMITED_PREC_MULT
static int find_affine_int(int np, const int *pts1, const int *pts2,
BLOCK_SIZE bsize, int mvy, int mvx,
WarpedMotionParams *wm, int mi_row, int mi_col) {
int32_t A[2][2] = { { 0, 0 }, { 0, 0 } };
int32_t Bx[2] = { 0, 0 };
int32_t By[2] = { 0, 0 };
const int bw = block_size_wide[bsize];
const int bh = block_size_high[bsize];
const int rsuy = bh / 2 - 1;
const int rsux = bw / 2 - 1;
const int suy = rsuy * 8;
const int sux = rsux * 8;
const int duy = suy + mvy;
const int dux = sux + mvx;
// Assume the center pixel of the block has exactly the same motion vector
// as transmitted for the block. First shift the origin of the source
// points to the block center, and the origin of the destination points to
// the block center added to the motion vector transmitted.
// Let (xi, yi) denote the source points and (xi', yi') denote destination
// points after origin shfifting, for i = 0, 1, 2, .... n-1.
// Then if P = [x0, y0,
// x1, y1
// x2, y1,
// ....
// ]
// q = [x0', x1', x2', ... ]'
// r = [y0', y1', y2', ... ]'
// the least squares problems that need to be solved are:
// [h1, h2]' = inv(P'P)P'q and
// [h3, h4]' = inv(P'P)P'r
// where the affine transformation is given by:
// x' = h1.x + h2.y
// y' = h3.x + h4.y
//
// The loop below computes: A = P'P, Bx = P'q, By = P'r
// We need to just compute inv(A).Bx and inv(A).By for the solutions.
// Contribution from neighbor block
for (int i = 0; i < np; i++) {
const int dx = pts2[i * 2] - dux;
const int dy = pts2[i * 2 + 1] - duy;
const int sx = pts1[i * 2] - sux;
const int sy = pts1[i * 2 + 1] - suy;
// (TODO)yunqing: This comparison wouldn't be necessary if the sample
// selection is done in find_samples(). Also, global offset can be removed
// while collecting samples.
if (abs(sx - dx) < LS_MV_MAX && abs(sy - dy) < LS_MV_MAX) {
A[0][0] += LS_SQUARE(sx);
A[0][1] += LS_PRODUCT1(sx, sy);
A[1][1] += LS_SQUARE(sy);
Bx[0] += LS_PRODUCT2(sx, dx);
Bx[1] += LS_PRODUCT1(sy, dx);
By[0] += LS_PRODUCT1(sx, dy);
By[1] += LS_PRODUCT2(sy, dy);
}
}
// Just for debugging, and can be removed later.
assert(A[0][0] >= LS_MAT_MIN && A[0][0] <= LS_MAT_MAX);
assert(A[0][1] >= LS_MAT_MIN && A[0][1] <= LS_MAT_MAX);
assert(A[1][1] >= LS_MAT_MIN && A[1][1] <= LS_MAT_MAX);
assert(Bx[0] >= LS_MAT_MIN && Bx[0] <= LS_MAT_MAX);
assert(Bx[1] >= LS_MAT_MIN && Bx[1] <= LS_MAT_MAX);
assert(By[0] >= LS_MAT_MIN && By[0] <= LS_MAT_MAX);
assert(By[1] >= LS_MAT_MIN && By[1] <= LS_MAT_MAX);
// Compute Determinant of A
const int64_t Det = (int64_t)A[0][0] * A[1][1] - (int64_t)A[0][1] * A[0][1];
if (Det == 0) return 1;
int16_t shift;
int16_t iDet = resolve_divisor_64(llabs(Det), &shift) * (Det < 0 ? -1 : 1);
shift -= WARPEDMODEL_PREC_BITS;
if (shift < 0) {
iDet <<= (-shift);
shift = 0;
}
int64_t Px[2], Py[2];
// These divided by the Det, are the least squares solutions
Px[0] = (int64_t)A[1][1] * Bx[0] - (int64_t)A[0][1] * Bx[1];
Px[1] = -(int64_t)A[0][1] * Bx[0] + (int64_t)A[0][0] * Bx[1];
Py[0] = (int64_t)A[1][1] * By[0] - (int64_t)A[0][1] * By[1];
Py[1] = -(int64_t)A[0][1] * By[0] + (int64_t)A[0][0] * By[1];
wm->wmmat[2] = get_mult_shift_diag(Px[0], iDet, shift);
wm->wmmat[3] = get_mult_shift_ndiag(Px[1], iDet, shift);
wm->wmmat[4] = get_mult_shift_ndiag(Py[0], iDet, shift);
wm->wmmat[5] = get_mult_shift_diag(Py[1], iDet, shift);
const int isuy = (mi_row * MI_SIZE + rsuy);
const int isux = (mi_col * MI_SIZE + rsux);
// Note: In the vx, vy expressions below, the max value of each of the
// 2nd and 3rd terms are (2^16 - 1) * (2^13 - 1). That leaves enough room
// for the first term so that the overall sum in the worst case fits
// within 32 bits overall.
const int32_t vx = mvx * (1 << (WARPEDMODEL_PREC_BITS - 3)) -
(isux * (wm->wmmat[2] - (1 << WARPEDMODEL_PREC_BITS)) +
isuy * wm->wmmat[3]);
const int32_t vy = mvy * (1 << (WARPEDMODEL_PREC_BITS - 3)) -
(isux * wm->wmmat[4] +
isuy * (wm->wmmat[5] - (1 << WARPEDMODEL_PREC_BITS)));
wm->wmmat[0] =
clamp(vx, -WARPEDMODEL_TRANS_CLAMP, WARPEDMODEL_TRANS_CLAMP - 1);
wm->wmmat[1] =
clamp(vy, -WARPEDMODEL_TRANS_CLAMP, WARPEDMODEL_TRANS_CLAMP - 1);
return 0;
}
int av1_find_projection(int np, const int *pts1, const int *pts2,
BLOCK_SIZE bsize, int mvy, int mvx,
WarpedMotionParams *wm_params, int mi_row, int mi_col) {
assert(wm_params->wmtype == AFFINE);
if (find_affine_int(np, pts1, pts2, bsize, mvy, mvx, wm_params, mi_row,
mi_col))
return 1;
// check compatibility with the fast warp filter
if (!av1_get_shear_params(wm_params)) return 1;
return 0;
}