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dvdsub_parser.c
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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 {
34 
36 {
37  return 0;
38 }
39 
41  AVCodecContext *avctx,
42  const uint8_t **poutbuf, int *poutbuf_size,
43  const uint8_t *buf, int buf_size)
44 {
46 
47  if (pc->packet_index == 0) {
48  if (buf_size < 2)
49  return 0;
50  pc->packet_len = AV_RB16(buf);
51  if (pc->packet_len == 0) /* HD-DVD subpicture packet */
52  pc->packet_len = AV_RB32(buf+2);
53  av_freep(&pc->packet);
54  pc->packet = av_malloc(pc->packet_len);
55  }
56  if (pc->packet) {
57  if (pc->packet_index + buf_size <= pc->packet_len) {
58  memcpy(pc->packet + pc->packet_index, buf, buf_size);
59  pc->packet_index += buf_size;
60  if (pc->packet_index >= pc->packet_len) {
61  *poutbuf = pc->packet;
62  *poutbuf_size = pc->packet_len;
63  pc->packet_index = 0;
64  return buf_size;
65  }
66  } else {
67  /* erroneous size */
68  pc->packet_index = 0;
69  }
70  }
71  *poutbuf = NULL;
72  *poutbuf_size = 0;
73  return buf_size;
74 }
75 
77 {
79  av_freep(&pc->packet);
80 }
81 
84  .priv_data_size = sizeof(DVDSubParseContext),
85  .parser_init = dvdsub_parse_init,
86  .parser_parse = dvdsub_parse,
87  .parser_close = dvdsub_parse_close,
88 };