1/*
2 * DVD subtitle decoding for ffmpeg
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 "libavutil/intreadwrite.h"
23#include "avcodec.h"
24
25/* parser definition */
26typedef struct DVDSubParseContext {
27    uint8_t *packet;
28    int packet_len;
29    int packet_index;
30} DVDSubParseContext;
31
32static av_cold int dvdsub_parse_init(AVCodecParserContext *s)
33{
34    return 0;
35}
36
37static int dvdsub_parse(AVCodecParserContext *s,
38                        AVCodecContext *avctx,
39                        const uint8_t **poutbuf, int *poutbuf_size,
40                        const uint8_t *buf, int buf_size)
41{
42    DVDSubParseContext *pc = s->priv_data;
43
44    if (pc->packet_index == 0) {
45        if (buf_size < 2)
46            return 0;
47        pc->packet_len = AV_RB16(buf);
48        if (pc->packet_len == 0) /* HD-DVD subpicture packet */
49            pc->packet_len = AV_RB32(buf+2);
50        av_freep(&pc->packet);
51        pc->packet = av_malloc(pc->packet_len);
52    }
53    if (pc->packet) {
54        if (pc->packet_index + buf_size <= pc->packet_len) {
55            memcpy(pc->packet + pc->packet_index, buf, buf_size);
56            pc->packet_index += buf_size;
57            if (pc->packet_index >= pc->packet_len) {
58                *poutbuf = pc->packet;
59                *poutbuf_size = pc->packet_len;
60                pc->packet_index = 0;
61                return buf_size;
62            }
63        } else {
64            /* erroneous size */
65            pc->packet_index = 0;
66        }
67    }
68    *poutbuf = NULL;
69    *poutbuf_size = 0;
70    return buf_size;
71}
72
73static av_cold void dvdsub_parse_close(AVCodecParserContext *s)
74{
75    DVDSubParseContext *pc = s->priv_data;
76    av_freep(&pc->packet);
77}
78
79AVCodecParser dvdsub_parser = {
80    { CODEC_ID_DVD_SUBTITLE },
81    sizeof(DVDSubParseContext),
82    dvdsub_parse_init,
83    dvdsub_parse,
84    dvdsub_parse_close,
85};
86