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 33static 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 51static 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 69static 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 89typedef struct XFaceContext { 90 uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding 91} XFaceContext; 92 93static 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 111static 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 179AVCodec 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}; 189