ref: 47be2ce4d1f4d2b50473a5ca4c11d0f8ad797eb5
dir: /src/cdef.c/
/* * Copyright © 2018, VideoLAN and dav1d authors * Copyright © 2018, Two Orioles, LLC * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 2001-2016, 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 "config.h" #include <assert.h> #include <stdlib.h> #include "common/intops.h" #include "src/cdef.h" static const int8_t cdef_directions4[8 /* dir */][2 /* pass */] = { { -1 * 8 + 1, -2 * 8 + 2 }, { 0 * 8 + 1, -1 * 8 + 2 }, { 0 * 8 + 1, 0 * 8 + 2 }, { 0 * 8 + 1, 1 * 8 + 2 }, { 1 * 8 + 1, 2 * 8 + 2 }, { 1 * 8 + 0, 2 * 8 + 1 }, { 1 * 8 + 0, 2 * 8 + 0 }, { 1 * 8 + 0, 2 * 8 - 1 } }; static const int8_t cdef_directions8[8 /* dir */][2 /* pass */] = { { -1 * 16 + 1, -2 * 16 + 2 }, { 0 * 16 + 1, -1 * 16 + 2 }, { 0 * 16 + 1, 0 * 16 + 2 }, { 0 * 16 + 1, 1 * 16 + 2 }, { 1 * 16 + 1, 2 * 16 + 2 }, { 1 * 16 + 0, 2 * 16 + 1 }, { 1 * 16 + 0, 2 * 16 + 0 }, { 1 * 16 + 0, 2 * 16 - 1 } }; static const uint8_t cdef_pri_taps[2][2] = { { 4, 2 }, { 3, 3 } }; static const uint8_t cdef_sec_taps[2][2] = { { 2, 1 }, { 2, 1 } }; static inline int constrain(const int diff, const int threshold, const int damping) { if (!threshold) return 0; const int shift = imax(0, damping - ulog2(threshold)); return apply_sign(imin(abs(diff), imax(0, threshold - (abs(diff) >> shift))), diff); } /* * <code partially copied from libaom> */ #define CDEF_VERY_LARGE (30000) static void fill(uint16_t *tmp, const ptrdiff_t stride, const int w, const int h) { for (int y = 0; y < h; y++) { for (int x = 0; x < w; x++) tmp[x] = CDEF_VERY_LARGE; tmp += stride; } } /* Smooth in the direction detected. */ static void cdef_filter_block_c(pixel *const dst, const ptrdiff_t dst_stride, /*const*/ pixel *const top[2], const int w, const int h, const int pri_strength, const int sec_strength, const int dir, const int damping, const enum CdefEdgeFlags edges) { const ptrdiff_t tmp_stride = 16 >> (w == 4); assert((w == 4 || w == 8) && (h == 4 || h == 8)); uint16_t tmp[192]; // 16*12 is the maximum value of tmp_stride * (h + 4) uint16_t *tmp2 = tmp + 2 * tmp_stride + 2; const uint8_t *const pri_taps = cdef_pri_taps[(pri_strength >> (BITDEPTH - 8)) & 1]; const uint8_t *const sec_taps = cdef_sec_taps[(pri_strength >> (BITDEPTH - 8)) & 1]; const int8_t (*cdef_directions)[2]; assert(w == 4 || w == 8); cdef_directions = w == 4 ? cdef_directions4 : cdef_directions8; // fill extended input buffer int x_start = -2, x_end = w + 2, y_start = -2, y_end = h + 2; if (!(edges & HAVE_TOP)) { fill(tmp, tmp_stride, w + 4, 2); y_start = 0; } if (!(edges & HAVE_BOTTOM)) { fill(tmp + (h + 2) * tmp_stride, tmp_stride, w + 4, 2); y_end -= 2; } if (!(edges & HAVE_LEFT)) { fill(tmp + (2 + y_start) * tmp_stride, tmp_stride, 2, y_end - y_start); x_start = 0; } if (!(edges & HAVE_RIGHT)) { fill(tmp + (2 + y_start) * tmp_stride + w + 2, tmp_stride, 2, y_end - y_start); x_end -= 2; } for (int y = y_start; y < 0; y++) for (int x = x_start; x < x_end; x++) tmp2[y * tmp_stride + x] = top[y & 1][x]; for (int y = 0; y < y_end; y++) for (int x = x_start; x < x_end; x++) tmp2[y * tmp_stride + x] = dst[y * PXSTRIDE(dst_stride) + x]; // run actual filter for (int y = 0; y < h; y++) { for (int x = 0; x < w; x++) { int sum = 0; const int px = dst[y * PXSTRIDE(dst_stride) + x]; int max = px, min = px; for (int k = 0; k < 2; k++) { const int8_t off1 = cdef_directions[dir][k]; const int p0 = tmp2[y * tmp_stride + x + off1]; const int p1 = tmp2[y * tmp_stride + x - off1]; sum += pri_taps[k] * constrain(p0 - px, pri_strength, damping); sum += pri_taps[k] * constrain(p1 - px, pri_strength, damping); if (p0 != CDEF_VERY_LARGE) max = imax(p0, max); if (p1 != CDEF_VERY_LARGE) max = imax(p1, max); min = imin(p0, min); min = imin(p1, min); const int8_t off2 = cdef_directions[(dir + 2) & 7][k]; const int s0 = tmp2[y * tmp_stride + x + off2]; const int s1 = tmp2[y * tmp_stride + x - off2]; const int8_t off3 = cdef_directions[(dir + 6) & 7][k]; const int s2 = tmp2[y * tmp_stride + x + off3]; const int s3 = tmp2[y * tmp_stride + x - off3]; if (s0 != CDEF_VERY_LARGE) max = imax(s0, max); if (s1 != CDEF_VERY_LARGE) max = imax(s1, max); if (s2 != CDEF_VERY_LARGE) max = imax(s2, max); if (s3 != CDEF_VERY_LARGE) max = imax(s3, max); min = imin(s0, min); min = imin(s1, min); min = imin(s2, min); min = imin(s3, min); sum += sec_taps[k] * constrain(s0 - px, sec_strength, damping); sum += sec_taps[k] * constrain(s1 - px, sec_strength, damping); sum += sec_taps[k] * constrain(s2 - px, sec_strength, damping); sum += sec_taps[k] * constrain(s3 - px, sec_strength, damping); } dst[y * PXSTRIDE(dst_stride) + x] = iclip(px + ((8 + sum - (sum < 0)) >> 4), min, max); } } } /* * </code partially copied from libaom> */ #define cdef_fn(w, h) \ static void cdef_filter_block_##w##x##h##_c(pixel *const dst, \ const ptrdiff_t stride, \ /*const*/ pixel *const top[2], \ const int pri_strength, \ const int sec_strength, \ const int dir, \ const int damping, \ const enum CdefEdgeFlags edges) \ { \ cdef_filter_block_c(dst, stride, top, w, h, pri_strength, sec_strength, \ dir, damping, edges); \ } cdef_fn(4, 4); cdef_fn(4, 8); cdef_fn(8, 8); /* * <code copied from libaom> */ /* Detect direction. 0 means 45-degree up-right, 2 is horizontal, and so on. The search minimizes the weighted variance along all the lines in a particular direction, i.e. the squared error between the input and a "predicted" block where each pixel is replaced by the average along a line in a particular direction. Since each direction have the same sum(x^2) term, that term is never computed. See Section 2, step 2, of: http://jmvalin.ca/notes/intra_paint.pdf */ static const uint16_t div_table[] = { 0, 840, 420, 280, 210, 168, 140, 120, 105 }; static int cdef_find_dir_c(const pixel *img, const ptrdiff_t stride, unsigned *const var) { int i; int32_t cost[8] = { 0 }; int partial[8][15] = { { 0 } }; int32_t best_cost = 0; int best_dir = 0; /* Instead of dividing by n between 2 and 8, we multiply by 3*5*7*8/n. The output is then 840 times larger, but we don't care for finding the max. */ for (i = 0; i < 8; i++) { int j; for (j = 0; j < 8; j++) { int x; /* We subtract 128 here to reduce the maximum range of the squared partial sums. */ x = (img[i * PXSTRIDE(stride) + j] >> (BITDEPTH - 8)) - 128; partial[0][i + j] += x; partial[1][i + j / 2] += x; partial[2][i] += x; partial[3][3 + i - j / 2] += x; partial[4][7 + i - j] += x; partial[5][3 - i / 2 + j] += x; partial[6][j] += x; partial[7][i / 2 + j] += x; } } for (i = 0; i < 8; i++) { cost[2] += partial[2][i] * partial[2][i]; cost[6] += partial[6][i] * partial[6][i]; } cost[2] *= div_table[8]; cost[6] *= div_table[8]; for (i = 0; i < 7; i++) { cost[0] += (partial[0][i] * partial[0][i] + partial[0][14 - i] * partial[0][14 - i]) * div_table[i + 1]; cost[4] += (partial[4][i] * partial[4][i] + partial[4][14 - i] * partial[4][14 - i]) * div_table[i + 1]; } cost[0] += partial[0][7] * partial[0][7] * div_table[8]; cost[4] += partial[4][7] * partial[4][7] * div_table[8]; for (i = 1; i < 8; i += 2) { int j; for (j = 0; j < 4 + 1; j++) { cost[i] += partial[i][3 + j] * partial[i][3 + j]; } cost[i] *= div_table[8]; for (j = 0; j < 4 - 1; j++) { cost[i] += (partial[i][j] * partial[i][j] + partial[i][10 - j] * partial[i][10 - j]) * div_table[2 * j + 2]; } } for (i = 0; i < 8; i++) { if (cost[i] > best_cost) { best_cost = cost[i]; best_dir = i; } } /* Difference between the optimal variance and the variance along the orthogonal direction. Again, the sum(x^2) terms cancel out. */ *var = best_cost - cost[(best_dir + 4) & 7]; /* We'd normally divide by 840, but dividing by 1024 is close enough for what we're going to do with this. */ *var >>= 10; return best_dir; } /* * </code copied from libaom> */ void bitfn(dav1d_cdef_dsp_init)(Dav1dCdefDSPContext *const c) { c->dir = cdef_find_dir_c; c->fb[0] = cdef_filter_block_8x8_c; c->fb[1] = cdef_filter_block_4x8_c; c->fb[2] = cdef_filter_block_4x4_c; }