| 1 | /* |
| 2 | * Copyright (c) 1990 James Ashton - Sydney University |
| 3 | * Copyright (c) 2012 Stefano Sabatini |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * X-Face decoder, based on libcompface, by James Ashton. |
| 25 | */ |
| 26 | |
| 27 | #include "libavutil/pixdesc.h" |
| 28 | #include "avcodec.h" |
| 29 | #include "bytestream.h" |
| 30 | #include "internal.h" |
| 31 | #include "xface.h" |
| 32 | |
| 33 | static int pop_integer(BigInt *b, const ProbRange *pranges) |
| 34 | { |
| 35 | uint8_t r; |
| 36 | int i; |
| 37 | |
| 38 | /* extract the last byte into r, and shift right b by 8 bits */ |
| 39 | ff_big_div(b, 0, &r); |
| 40 | |
| 41 | i = 0; |
| 42 | while (r < pranges->offset || r >= pranges->range + pranges->offset) { |
| 43 | pranges++; |
| 44 | i++; |
| 45 | } |
| 46 | ff_big_mul(b, pranges->range); |
| 47 | ff_big_add(b, r - pranges->offset); |
| 48 | return i; |
| 49 | } |
| 50 | |
| 51 | static void pop_greys(BigInt *b, char *bitmap, int w, int h) |
| 52 | { |
| 53 | if (w > 3) { |
| 54 | w /= 2; |
| 55 | h /= 2; |
| 56 | pop_greys(b, bitmap, w, h); |
| 57 | pop_greys(b, bitmap + w, w, h); |
| 58 | pop_greys(b, bitmap + XFACE_WIDTH * h, w, h); |
| 59 | pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h); |
| 60 | } else { |
| 61 | w = pop_integer(b, ff_xface_probranges_2x2); |
| 62 | if (w & 1) bitmap[0] = 1; |
| 63 | if (w & 2) bitmap[1] = 1; |
| 64 | if (w & 4) bitmap[XFACE_WIDTH] = 1; |
| 65 | if (w & 8) bitmap[XFACE_WIDTH + 1] = 1; |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | static void decode_block(BigInt *b, char *bitmap, int w, int h, int level) |
| 70 | { |
| 71 | switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) { |
| 72 | case XFACE_COLOR_WHITE: |
| 73 | return; |
| 74 | case XFACE_COLOR_BLACK: |
| 75 | pop_greys(b, bitmap, w, h); |
| 76 | return; |
| 77 | default: |
| 78 | w /= 2; |
| 79 | h /= 2; |
| 80 | level++; |
| 81 | decode_block(b, bitmap, w, h, level); |
| 82 | decode_block(b, bitmap + w, w, h, level); |
| 83 | decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level); |
| 84 | decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level); |
| 85 | return; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | typedef struct XFaceContext { |
| 90 | uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding |
| 91 | } XFaceContext; |
| 92 | |
| 93 | static av_cold int xface_decode_init(AVCodecContext *avctx) |
| 94 | { |
| 95 | if (avctx->width || avctx->height) { |
| 96 | if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) { |
| 97 | av_log(avctx, AV_LOG_ERROR, |
| 98 | "Size value %dx%d not supported, only accepts a size of %dx%d\n", |
| 99 | avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT); |
| 100 | return AVERROR(EINVAL); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | avctx->width = XFACE_WIDTH; |
| 105 | avctx->height = XFACE_HEIGHT; |
| 106 | avctx->pix_fmt = AV_PIX_FMT_MONOWHITE; |
| 107 | |
| 108 | return 0; |
| 109 | } |
| 110 | |
| 111 | static int xface_decode_frame(AVCodecContext *avctx, |
| 112 | void *data, int *got_frame, |
| 113 | AVPacket *avpkt) |
| 114 | { |
| 115 | XFaceContext *xface = avctx->priv_data; |
| 116 | int ret, i, j, k; |
| 117 | uint8_t byte; |
| 118 | BigInt b = {0}; |
| 119 | char *buf; |
| 120 | int64_t c; |
| 121 | AVFrame *frame = data; |
| 122 | |
| 123 | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
| 124 | return ret; |
| 125 | |
| 126 | for (i = 0, k = 0; avpkt->data[i] && i < avpkt->size; i++) { |
| 127 | c = avpkt->data[i]; |
| 128 | |
| 129 | /* ignore invalid digits */ |
| 130 | if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT) |
| 131 | continue; |
| 132 | |
| 133 | if (++k > XFACE_MAX_DIGITS) { |
| 134 | av_log(avctx, AV_LOG_WARNING, |
| 135 | "Buffer is longer than expected, truncating at byte %d\n", i); |
| 136 | break; |
| 137 | } |
| 138 | ff_big_mul(&b, XFACE_PRINTS); |
| 139 | ff_big_add(&b, c - XFACE_FIRST_PRINT); |
| 140 | } |
| 141 | |
| 142 | /* decode image and put it in bitmap */ |
| 143 | memset(xface->bitmap, 0, XFACE_PIXELS); |
| 144 | buf = xface->bitmap; |
| 145 | decode_block(&b, buf, 16, 16, 0); |
| 146 | decode_block(&b, buf + 16, 16, 16, 0); |
| 147 | decode_block(&b, buf + 32, 16, 16, 0); |
| 148 | decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0); |
| 149 | decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0); |
| 150 | decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0); |
| 151 | decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0); |
| 152 | decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0); |
| 153 | decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0); |
| 154 | |
| 155 | ff_xface_generate_face(xface->bitmap, xface->bitmap); |
| 156 | |
| 157 | /* convert image from 1=black 0=white bitmap to MONOWHITE */ |
| 158 | buf = frame->data[0]; |
| 159 | for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) { |
| 160 | byte += xface->bitmap[i]; |
| 161 | if (k == 7) { |
| 162 | buf[j++] = byte; |
| 163 | byte = k = 0; |
| 164 | } else { |
| 165 | k++; |
| 166 | byte <<= 1; |
| 167 | } |
| 168 | if (j == XFACE_WIDTH/8) { |
| 169 | j = 0; |
| 170 | buf += frame->linesize[0]; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | *got_frame = 1; |
| 175 | |
| 176 | return avpkt->size; |
| 177 | } |
| 178 | |
| 179 | AVCodec ff_xface_decoder = { |
| 180 | .name = "xface", |
| 181 | .long_name = NULL_IF_CONFIG_SMALL("X-face image"), |
| 182 | .type = AVMEDIA_TYPE_VIDEO, |
| 183 | .id = AV_CODEC_ID_XFACE, |
| 184 | .priv_data_size = sizeof(XFaceContext), |
| 185 | .init = xface_decode_init, |
| 186 | .decode = xface_decode_frame, |
| 187 | .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE }, |
| 188 | }; |