| 1 | /* |
| 2 | * H261 common code |
| 3 | * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> |
| 4 | * Copyright (c) 2004 Maarten Daniels |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * @file |
| 25 | * h261codec. |
| 26 | */ |
| 27 | |
| 28 | #include "avcodec.h" |
| 29 | #include "h261.h" |
| 30 | |
| 31 | #define IS_FIL(a) ((a) & MB_TYPE_H261_FIL) |
| 32 | |
| 33 | uint8_t ff_h261_rl_table_store[2][2 * MAX_RUN + MAX_LEVEL + 3]; |
| 34 | |
| 35 | static void h261_loop_filter(uint8_t *src, int stride) |
| 36 | { |
| 37 | int x, y, xy, yz; |
| 38 | int temp[64]; |
| 39 | |
| 40 | for (x = 0; x < 8; x++) { |
| 41 | temp[x] = 4 * src[x]; |
| 42 | temp[x + 7 * 8] = 4 * src[x + 7 * stride]; |
| 43 | } |
| 44 | for (y = 1; y < 7; y++) { |
| 45 | for (x = 0; x < 8; x++) { |
| 46 | xy = y * stride + x; |
| 47 | yz = y * 8 + x; |
| 48 | temp[yz] = src[xy - stride] + 2 * src[xy] + src[xy + stride]; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | for (y = 0; y < 8; y++) { |
| 53 | src[y * stride] = (temp[y * 8] + 2) >> 2; |
| 54 | src[y * stride + 7] = (temp[y * 8 + 7] + 2) >> 2; |
| 55 | for (x = 1; x < 7; x++) { |
| 56 | xy = y * stride + x; |
| 57 | yz = y * 8 + x; |
| 58 | src[xy] = (temp[yz - 1] + 2 * temp[yz] + temp[yz + 1] + 8) >> 4; |
| 59 | } |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | void ff_h261_loop_filter(MpegEncContext *s) |
| 64 | { |
| 65 | H261Context *h = (H261Context *)s; |
| 66 | const int linesize = s->linesize; |
| 67 | const int uvlinesize = s->uvlinesize; |
| 68 | uint8_t *dest_y = s->dest[0]; |
| 69 | uint8_t *dest_cb = s->dest[1]; |
| 70 | uint8_t *dest_cr = s->dest[2]; |
| 71 | |
| 72 | if (!(IS_FIL(h->mtype))) |
| 73 | return; |
| 74 | |
| 75 | h261_loop_filter(dest_y, linesize); |
| 76 | h261_loop_filter(dest_y + 8, linesize); |
| 77 | h261_loop_filter(dest_y + 8 * linesize, linesize); |
| 78 | h261_loop_filter(dest_y + 8 * linesize + 8, linesize); |
| 79 | h261_loop_filter(dest_cb, uvlinesize); |
| 80 | h261_loop_filter(dest_cr, uvlinesize); |
| 81 | } |
| 82 | |
| 83 | av_cold void ff_h261_common_init(void) |
| 84 | { |
| 85 | static int done = 0; |
| 86 | |
| 87 | if (done) |
| 88 | return; |
| 89 | |
| 90 | ff_init_rl(&ff_h261_rl_tcoeff, ff_h261_rl_table_store); |
| 91 | done = 1; |
| 92 | } |