| 1 | /* |
| 2 | * This file is part of FFmpeg. |
| 3 | * |
| 4 | * FFmpeg is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * FFmpeg is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with FFmpeg; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #include <stdint.h> |
| 20 | |
| 21 | #include "libavutil/attributes.h" |
| 22 | #include "libavutil/common.h" |
| 23 | #include "config.h" |
| 24 | #include "h263dsp.h" |
| 25 | |
| 26 | const uint8_t ff_h263_loop_filter_strength[32] = { |
| 27 | 0, 1, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 7, 7, |
| 28 | 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11, 11, 11, 12, 12, 12 |
| 29 | }; |
| 30 | |
| 31 | static void h263_h_loop_filter_c(uint8_t *src, int stride, int qscale) |
| 32 | { |
| 33 | int y; |
| 34 | const int strength = ff_h263_loop_filter_strength[qscale]; |
| 35 | |
| 36 | for (y = 0; y < 8; y++) { |
| 37 | int d1, d2, ad1; |
| 38 | int p0 = src[y * stride - 2]; |
| 39 | int p1 = src[y * stride - 1]; |
| 40 | int p2 = src[y * stride + 0]; |
| 41 | int p3 = src[y * stride + 1]; |
| 42 | int d = (p0 - p3 + 4 * (p2 - p1)) / 8; |
| 43 | |
| 44 | if (d < -2 * strength) |
| 45 | d1 = 0; |
| 46 | else if (d < -strength) |
| 47 | d1 = -2 * strength - d; |
| 48 | else if (d < strength) |
| 49 | d1 = d; |
| 50 | else if (d < 2 * strength) |
| 51 | d1 = 2 * strength - d; |
| 52 | else |
| 53 | d1 = 0; |
| 54 | |
| 55 | p1 += d1; |
| 56 | p2 -= d1; |
| 57 | if (p1 & 256) |
| 58 | p1 = ~(p1 >> 31); |
| 59 | if (p2 & 256) |
| 60 | p2 = ~(p2 >> 31); |
| 61 | |
| 62 | src[y * stride - 1] = p1; |
| 63 | src[y * stride + 0] = p2; |
| 64 | |
| 65 | ad1 = FFABS(d1) >> 1; |
| 66 | |
| 67 | d2 = av_clip((p0 - p3) / 4, -ad1, ad1); |
| 68 | |
| 69 | src[y * stride - 2] = p0 - d2; |
| 70 | src[y * stride + 1] = p3 + d2; |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | static void h263_v_loop_filter_c(uint8_t *src, int stride, int qscale) |
| 75 | { |
| 76 | int x; |
| 77 | const int strength = ff_h263_loop_filter_strength[qscale]; |
| 78 | |
| 79 | for (x = 0; x < 8; x++) { |
| 80 | int d1, d2, ad1; |
| 81 | int p0 = src[x - 2 * stride]; |
| 82 | int p1 = src[x - 1 * stride]; |
| 83 | int p2 = src[x + 0 * stride]; |
| 84 | int p3 = src[x + 1 * stride]; |
| 85 | int d = (p0 - p3 + 4 * (p2 - p1)) / 8; |
| 86 | |
| 87 | if (d < -2 * strength) |
| 88 | d1 = 0; |
| 89 | else if (d < -strength) |
| 90 | d1 = -2 * strength - d; |
| 91 | else if (d < strength) |
| 92 | d1 = d; |
| 93 | else if (d < 2 * strength) |
| 94 | d1 = 2 * strength - d; |
| 95 | else |
| 96 | d1 = 0; |
| 97 | |
| 98 | p1 += d1; |
| 99 | p2 -= d1; |
| 100 | if (p1 & 256) |
| 101 | p1 = ~(p1 >> 31); |
| 102 | if (p2 & 256) |
| 103 | p2 = ~(p2 >> 31); |
| 104 | |
| 105 | src[x - 1 * stride] = p1; |
| 106 | src[x + 0 * stride] = p2; |
| 107 | |
| 108 | ad1 = FFABS(d1) >> 1; |
| 109 | |
| 110 | d2 = av_clip((p0 - p3) / 4, -ad1, ad1); |
| 111 | |
| 112 | src[x - 2 * stride] = p0 - d2; |
| 113 | src[x + stride] = p3 + d2; |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | av_cold void ff_h263dsp_init(H263DSPContext *ctx) |
| 118 | { |
| 119 | ctx->h263_h_loop_filter = h263_h_loop_filter_c; |
| 120 | ctx->h263_v_loop_filter = h263_v_loop_filter_c; |
| 121 | |
| 122 | if (ARCH_X86) |
| 123 | ff_h263dsp_init_x86(ctx); |
| 124 | } |