aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/realtextdec.c
blob: 713e174b92f3b9720ea8d41b0a840e316be51d50 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * Copyright (c) 2012 Clément Bœsch
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * RealText subtitle demuxer
 * @see http://service.real.com/help/library/guides/ProductionGuide/prodguide/htmfiles/realtext.htm
 */

#include "avformat.h"
#include "demux.h"
#include "internal.h"
#include "subtitles.h"
#include "libavutil/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/intreadwrite.h"

typedef struct {
    FFDemuxSubtitlesQueue q;
} RealTextContext;

static int realtext_probe(const AVProbeData *p)
{
    char buf[7];
    FFTextReader tr;
    ff_text_init_buf(&tr, p->buf, p->buf_size);
    ff_text_read(&tr, buf, sizeof(buf));

    return !av_strncasecmp(buf, "<window", 7) ? AVPROBE_SCORE_EXTENSION : 0;
}

static int64_t read_ts(const char *s)
{
    int hh, mm, ss, ms;

    if (sscanf(s, "%u:%u:%u.%u", &hh, &mm, &ss, &ms) == 4) return (hh*3600LL + mm*60LL + ss) * 100LL + ms;
    if (sscanf(s, "%u:%u:%u"   , &hh, &mm, &ss     ) == 3) return (hh*3600LL + mm*60LL + ss) * 100LL;
    if (sscanf(s,    "%u:%u.%u",      &mm, &ss, &ms) == 3) return (            mm*60LL + ss) * 100LL + ms;
    if (sscanf(s,    "%u:%u"   ,      &mm, &ss     ) == 2) return (            mm*60LL + ss) * 100LL;
    if (sscanf(s,       "%u.%u",           &ss, &ms) == 2) return (                      ss) * 100LL + ms;
    return strtoll(s, NULL, 10) * 100ULL;
}

static int realtext_read_header(AVFormatContext *s)
{
    RealTextContext *rt = s->priv_data;
    AVStream *st = avformat_new_stream(s, NULL);
    AVBPrint buf;
    char c = 0;
    int res = 0, duration = read_ts("60"); // default duration is 60 seconds
    FFTextReader tr;
    ff_text_init_avio(s, &tr, s->pb);

    if (!st)
        return AVERROR(ENOMEM);
    avpriv_set_pts_info(st, 64, 1, 100);
    st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
    st->codecpar->codec_id   = AV_CODEC_ID_REALTEXT;

    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);

    while (!ff_text_eof(&tr)) {
        AVPacket *sub;
        const int64_t pos = ff_text_pos(&tr) - (c != 0);
        int n = ff_smil_extract_next_text_chunk(&tr, &buf, &c);

        if (n < 0) {
            res = n;
            goto end;
        }
        if (n == 0)
            break;

        if (!av_strncasecmp(buf.str, "<window", 7)) {
            /* save header to extradata */
            const char *p = ff_smil_get_attr_ptr(buf.str, "duration");

            if (st->codecpar->extradata) {
                res = AVERROR_INVALIDDATA;
                goto end;
            }
            if (p)
                duration = read_ts(p);
            st->codecpar->extradata = av_strdup(buf.str);
            if (!st->codecpar->extradata) {
                res = AVERROR(ENOMEM);
                goto end;
            }
            st->codecpar->extradata_size = buf.len + 1;
        } else {
            /* if we just read a <time> tag, introduce a new event, otherwise merge
             * with the previous one */
            int merge = !av_strncasecmp(buf.str, "<time", 5) ? 0 : 1;
            sub = ff_subtitles_queue_insert_bprint(&rt->q, &buf, merge);
            if (!sub) {
                res = AVERROR(ENOMEM);
                goto end;
            }
            if (!merge) {
                const char *begin = ff_smil_get_attr_ptr(buf.str, "begin");
                const char *end   = ff_smil_get_attr_ptr(buf.str, "end");
                int64_t endi = end ? read_ts(end) : 0;

                sub->pos      = pos;
                sub->pts      = begin ? read_ts(begin) : 0;
                sub->duration = (end && endi > sub->pts && endi - (uint64_t)sub->pts <= INT64_MAX) ? endi - sub->pts : duration;
            }
        }
        av_bprint_clear(&buf);
    }
    ff_subtitles_queue_finalize(s, &rt->q);

end:
    av_bprint_finalize(&buf, NULL);
    return res;
}

const FFInputFormat ff_realtext_demuxer = {
    .p.name         = "realtext",
    .p.long_name    = NULL_IF_CONFIG_SMALL("RealText subtitle format"),
    .p.extensions   = "rt",
    .priv_data_size = sizeof(RealTextContext),
    .flags_internal = FF_FMT_INIT_CLEANUP,
    .read_probe     = realtext_probe,
    .read_header    = realtext_read_header,
    .read_packet    = ff_subtitles_read_packet,
    .read_seek2     = ff_subtitles_read_seek,
    .read_close     = ff_subtitles_read_close,
};