Statistics
| Branch: | Revision:

ffmpeg / libavformat / srtdec.c @ 66e5b1df

History | View | Annotate | Download (2.94 KB)

1
/*
2
 * SubRip subtitle demuxer
3
 * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
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 "avformat.h"
23
#include "internal.h"
24
#include "libavutil/intreadwrite.h"
25

    
26
static int srt_probe(AVProbeData *p)
27
{
28
    unsigned char *ptr = p->buf;
29
    int i, v, num = 0;
30

    
31
    if (AV_RB24(ptr) == 0xEFBBBF)
32
        ptr += 3;  /* skip UTF-8 BOM */
33

    
34
    for (i=0; i<2; i++) {
35
        if (num == i && sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
36
            return AVPROBE_SCORE_MAX;
37
        num = atoi(ptr);
38
        ptr += strcspn(ptr, "\n") + 1;
39
    }
40
    return 0;
41
}
42

    
43
static int srt_read_header(AVFormatContext *s, AVFormatParameters *ap)
44
{
45
    AVStream *st = av_new_stream(s, 0);
46
    if (!st)
47
        return -1;
48
    av_set_pts_info(st, 64, 1, 1000);
49
    st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
50
    st->codec->codec_id   = CODEC_ID_SRT;
51
    return 0;
52
}
53

    
54
static int64_t get_pts(const char *buf)
55
{
56
    int i, v, hour, min, sec, hsec;
57

    
58
    for (i=0; i<2; i++) {
59
        if (sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %*d:%*2d:%*2d%*1[,.]%3d",
60
                   &hour, &min, &sec, &hsec, &v) == 5) {
61
            min += 60*hour;
62
            sec += 60*min;
63
            return sec*1000+hsec;
64
        }
65
        buf += strcspn(buf, "\n") + 1;
66
    }
67
    return AV_NOPTS_VALUE;
68
}
69

    
70
static inline int is_eol(char c)
71
{
72
    return c == '\r' || c == '\n';
73
}
74

    
75
static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
76
{
77
    char buffer[2048], *ptr = buffer, *ptr2;
78
    int64_t pos = avio_tell(s->pb);
79
    int res = AVERROR_EOF;
80

    
81
    do {
82
        ptr2 = ptr;
83
        ptr += ff_get_line(s->pb, ptr, sizeof(buffer)+buffer-ptr);
84
    } while (!is_eol(*ptr2) && !s->pb->eof_reached && ptr-buffer<sizeof(buffer)-1);
85

    
86
    if (buffer[0] && !(res = av_new_packet(pkt, ptr-buffer))) {
87
        memcpy(pkt->data, buffer, pkt->size);
88
        pkt->flags |= AV_PKT_FLAG_KEY;
89
        pkt->pos = pos;
90
        pkt->pts = pkt->dts = get_pts(pkt->data);
91
    }
92
    return res;
93
}
94

    
95
AVInputFormat ff_srt_demuxer = {
96
    .name        = "srt",
97
    .long_name   = NULL_IF_CONFIG_SMALL("SubRip subtitle format"),
98
    .read_probe  = srt_probe,
99
    .read_header = srt_read_header,
100
    .read_packet = srt_read_packet,
101
    .flags       = AVFMT_GENERIC_INDEX,
102
};