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 "codec_internal.h" 31#include "internal.h" 32#include "xface.h" 33 34static int pop_integer(BigInt *b, const ProbRange *pranges) 35{ 36 uint8_t r; 37 int i; 38 39 /* extract the last byte into r, and shift right b by 8 bits */ 40 ff_big_div(b, 0, &r); 41 42 i = 0; 43 while (r < pranges->offset || r >= pranges->range + pranges->offset) { 44 pranges++; 45 i++; 46 } 47 ff_big_mul(b, pranges->range); 48 ff_big_add(b, r - pranges->offset); 49 return i; 50} 51 52static void pop_greys(BigInt *b, char *bitmap, int w, int h) 53{ 54 if (w > 3) { 55 w /= 2; 56 h /= 2; 57 pop_greys(b, bitmap, w, h); 58 pop_greys(b, bitmap + w, w, h); 59 pop_greys(b, bitmap + XFACE_WIDTH * h, w, h); 60 pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h); 61 } else { 62 w = pop_integer(b, ff_xface_probranges_2x2); 63 if (w & 1) bitmap[0] = 1; 64 if (w & 2) bitmap[1] = 1; 65 if (w & 4) bitmap[XFACE_WIDTH] = 1; 66 if (w & 8) bitmap[XFACE_WIDTH + 1] = 1; 67 } 68} 69 70static void decode_block(BigInt *b, char *bitmap, int w, int h, int level) 71{ 72 switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) { 73 case XFACE_COLOR_WHITE: 74 return; 75 case XFACE_COLOR_BLACK: 76 pop_greys(b, bitmap, w, h); 77 return; 78 default: 79 w /= 2; 80 h /= 2; 81 level++; 82 decode_block(b, bitmap, w, h, level); 83 decode_block(b, bitmap + w, w, h, level); 84 decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level); 85 decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level); 86 return; 87 } 88} 89 90typedef struct XFaceContext { 91 uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding 92} XFaceContext; 93 94static av_cold int xface_decode_init(AVCodecContext *avctx) 95{ 96 if (avctx->width || avctx->height) { 97 if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) { 98 av_log(avctx, AV_LOG_ERROR, 99 "Size value %dx%d not supported, only accepts a size of %dx%d\n", 100 avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT); 101 return AVERROR(EINVAL); 102 } 103 } 104 105 avctx->width = XFACE_WIDTH; 106 avctx->height = XFACE_HEIGHT; 107 avctx->pix_fmt = AV_PIX_FMT_MONOWHITE; 108 109 return 0; 110} 111 112static int xface_decode_frame(AVCodecContext *avctx, AVFrame *frame, 113 int *got_frame, 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; 121 122 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 123 return ret; 124 125 for (i = 0, k = 0; i < avpkt->size && avpkt->data[i]; i++) { 126 c = avpkt->data[i]; 127 128 /* ignore invalid digits */ 129 if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT) 130 continue; 131 132 if (++k > XFACE_MAX_DIGITS) { 133 av_log(avctx, AV_LOG_WARNING, 134 "Buffer is longer than expected, truncating at byte %d\n", i); 135 break; 136 } 137 ff_big_mul(&b, XFACE_PRINTS); 138 ff_big_add(&b, c - XFACE_FIRST_PRINT); 139 } 140 141 /* decode image and put it in bitmap */ 142 memset(xface->bitmap, 0, XFACE_PIXELS); 143 buf = xface->bitmap; 144 decode_block(&b, buf, 16, 16, 0); 145 decode_block(&b, buf + 16, 16, 16, 0); 146 decode_block(&b, buf + 32, 16, 16, 0); 147 decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0); 148 decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0); 149 decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0); 150 decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0); 151 decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0); 152 decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0); 153 154 ff_xface_generate_face(xface->bitmap, xface->bitmap); 155 156 /* convert image from 1=black 0=white bitmap to MONOWHITE */ 157 buf = frame->data[0]; 158 for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) { 159 byte += xface->bitmap[i]; 160 if (k == 7) { 161 buf[j++] = byte; 162 byte = k = 0; 163 } else { 164 k++; 165 byte <<= 1; 166 } 167 if (j == XFACE_WIDTH/8) { 168 j = 0; 169 buf += frame->linesize[0]; 170 } 171 } 172 173 *got_frame = 1; 174 175 return avpkt->size; 176} 177 178const FFCodec ff_xface_decoder = { 179 .p.name = "xface", 180 .p.long_name = NULL_IF_CONFIG_SMALL("X-face image"), 181 .p.type = AVMEDIA_TYPE_VIDEO, 182 .p.id = AV_CODEC_ID_XFACE, 183 .p.capabilities = AV_CODEC_CAP_DR1, 184 .priv_data_size = sizeof(XFaceContext), 185 .init = xface_decode_init, 186 FF_CODEC_DECODE_CB(xface_decode_frame), 187 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE }, 188 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 189}; 190