blob: 32a945ed6532f227b5154cddd00dbd218b5be498
1 | /* |
2 | * DVD subtitle decoding |
3 | * Copyright (c) 2005 Fabrice Bellard |
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 | #include <string.h> |
23 | |
24 | #include "libavutil/intreadwrite.h" |
25 | #include "libavutil/mem.h" |
26 | #include "avcodec.h" |
27 | |
28 | /* parser definition */ |
29 | typedef struct DVDSubParseContext { |
30 | uint8_t *packet; |
31 | int packet_len; |
32 | int packet_index; |
33 | } DVDSubParseContext; |
34 | |
35 | static av_cold int dvdsub_parse_init(AVCodecParserContext *s) |
36 | { |
37 | return 0; |
38 | } |
39 | |
40 | static int dvdsub_parse(AVCodecParserContext *s, |
41 | AVCodecContext *avctx, |
42 | const uint8_t **poutbuf, int *poutbuf_size, |
43 | const uint8_t *buf, int buf_size) |
44 | { |
45 | DVDSubParseContext *pc = s->priv_data; |
46 | |
47 | if (pc->packet_index == 0) { |
48 | if (buf_size < 2 || AV_RB16(buf) && buf_size < 6) { |
49 | if (buf_size) |
50 | av_log(avctx, AV_LOG_DEBUG, "Parser input %d too small\n", buf_size); |
51 | return buf_size; |
52 | } |
53 | pc->packet_len = AV_RB16(buf); |
54 | if (pc->packet_len == 0) /* HD-DVD subpicture packet */ |
55 | pc->packet_len = AV_RB32(buf+2); |
56 | av_freep(&pc->packet); |
57 | pc->packet = av_malloc(pc->packet_len); |
58 | } |
59 | if (pc->packet) { |
60 | if (pc->packet_index + buf_size <= pc->packet_len) { |
61 | memcpy(pc->packet + pc->packet_index, buf, buf_size); |
62 | pc->packet_index += buf_size; |
63 | if (pc->packet_index >= pc->packet_len) { |
64 | *poutbuf = pc->packet; |
65 | *poutbuf_size = pc->packet_len; |
66 | pc->packet_index = 0; |
67 | return buf_size; |
68 | } |
69 | } else { |
70 | /* erroneous size */ |
71 | pc->packet_index = 0; |
72 | } |
73 | } |
74 | *poutbuf = NULL; |
75 | *poutbuf_size = 0; |
76 | return buf_size; |
77 | } |
78 | |
79 | static av_cold void dvdsub_parse_close(AVCodecParserContext *s) |
80 | { |
81 | DVDSubParseContext *pc = s->priv_data; |
82 | av_freep(&pc->packet); |
83 | } |
84 | |
85 | AVCodecParser ff_dvdsub_parser = { |
86 | .codec_ids = { AV_CODEC_ID_DVD_SUBTITLE }, |
87 | .priv_data_size = sizeof(DVDSubParseContext), |
88 | .parser_init = dvdsub_parse_init, |
89 | .parser_parse = dvdsub_parse, |
90 | .parser_close = dvdsub_parse_close, |
91 | }; |
92 |