1/* 2 * XBM image format 3 * 4 * Copyright (c) 2012 Paul B Mahol 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#include "libavutil/avstring.h" 24 25#include "avcodec.h" 26#include "internal.h" 27#include "mathops.h" 28 29static int convert(uint8_t x) 30{ 31 if (x >= 'a') 32 x -= 87; 33 else if (x >= 'A') 34 x -= 55; 35 else 36 x -= '0'; 37 return x; 38} 39 40static int parse_str_int(const uint8_t *p, int len, const uint8_t *key) 41{ 42 const uint8_t *end = p + len; 43 44 for(; p<end - strlen(key); p++) { 45 if (!memcmp(p, key, strlen(key))) 46 break; 47 } 48 p += strlen(key); 49 if (p >= end) 50 return INT_MIN; 51 52 for(; p<end; p++) { 53 char *eptr; 54 int64_t ret = strtol(p, &eptr, 10); 55 if ((const uint8_t *)eptr != p) 56 return ret; 57 } 58 return INT_MIN; 59} 60 61static int xbm_decode_frame(AVCodecContext *avctx, void *data, 62 int *got_frame, AVPacket *avpkt) 63{ 64 AVFrame *p = data; 65 int ret, linesize, i, j; 66 int width = 0; 67 int height = 0; 68 const uint8_t *end, *ptr = avpkt->data; 69 const uint8_t *next; 70 uint8_t *dst; 71 72 avctx->pix_fmt = AV_PIX_FMT_MONOWHITE; 73 end = avpkt->data + avpkt->size; 74 75 width = parse_str_int(avpkt->data, avpkt->size, "_width"); 76 height = parse_str_int(avpkt->data, avpkt->size, "_height"); 77 78 if ((ret = ff_set_dimensions(avctx, width, height)) < 0) 79 return ret; 80 81 if ((ret = ff_get_buffer(avctx, p, 0)) < 0) 82 return ret; 83 84 // goto start of image data 85 next = memchr(ptr, '{', avpkt->size); 86 if (!next) 87 next = memchr(ptr, '(', avpkt->size); 88 if (!next) 89 return AVERROR_INVALIDDATA; 90 ptr = next + 1; 91 92 linesize = (avctx->width + 7) / 8; 93 for (i = 0; i < avctx->height; i++) { 94 dst = p->data[0] + i * p->linesize[0]; 95 for (j = 0; j < linesize; j++) { 96 uint8_t val; 97 98 while (ptr < end && *ptr != 'x' && *ptr != '$') 99 ptr++; 100 101 ptr ++; 102 if (ptr < end && av_isxdigit(*ptr)) { 103 val = convert(*ptr++); 104 if (av_isxdigit(*ptr)) 105 val = (val << 4) + convert(*ptr++); 106 *dst++ = ff_reverse[val]; 107 if (av_isxdigit(*ptr) && j+1 < linesize) { 108 j++; 109 val = convert(*ptr++); 110 if (av_isxdigit(*ptr)) 111 val = (val << 4) + convert(*ptr++); 112 *dst++ = ff_reverse[val]; 113 } 114 } else { 115 av_log(avctx, AV_LOG_ERROR, 116 "Unexpected data at %.8s.\n", ptr); 117 return AVERROR_INVALIDDATA; 118 } 119 } 120 } 121 122 p->key_frame = 1; 123 p->pict_type = AV_PICTURE_TYPE_I; 124 125 *got_frame = 1; 126 127 return avpkt->size; 128} 129 130AVCodec ff_xbm_decoder = { 131 .name = "xbm", 132 .long_name = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"), 133 .type = AVMEDIA_TYPE_VIDEO, 134 .id = AV_CODEC_ID_XBM, 135 .decode = xbm_decode_frame, 136 .capabilities = CODEC_CAP_DR1, 137}; 138