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2ba45a60 DM |
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 | ||
29 | static 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 | ||
40 | static 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 | ||
61 | static 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 | ||
130 | AVCodec 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 | }; |