1 /*
2 * Copyright (c) 2014 Eejya Singh
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * STL subtitles format demuxer
24 * @see https://documentation.apple.com/en/dvdstudiopro/usermanual/index.html#chapter=19%26section=13%26tasks=true
25 */
26
27 #include "avformat.h"
28 #include "internal.h"
29 #include "subtitles.h"
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/avstring.h"
32
33 typedef struct {
34 FFDemuxSubtitlesQueue q;
35 } STLContext;
36
stl_probe(const AVProbeData * p)37 static int stl_probe(const AVProbeData *p)
38 {
39 char c;
40 const unsigned char *ptr = p->buf;
41
42 if (AV_RB24(ptr) == 0xEFBBBF)
43 ptr += 3; /* skip UTF-8 BOM */
44
45 while (*ptr == '\r' || *ptr == '\n' || *ptr == '$' || !strncmp(ptr, "//" , 2))
46 ptr += ff_subtitles_next_line(ptr);
47
48 if (sscanf(ptr, "%*d:%*d:%*d:%*d , %*d:%*d:%*d:%*d , %c", &c) == 1)
49 return AVPROBE_SCORE_MAX;
50
51 return 0;
52 }
53
get_pts(char ** buf,int * duration)54 static int64_t get_pts(char **buf, int *duration)
55 {
56 int hh1, mm1, ss1, ms1;
57 int hh2, mm2, ss2, ms2;
58 int len = 0;
59
60 if (sscanf(*buf, "%2d:%2d:%2d:%2d , %2d:%2d:%2d:%2d , %n",
61 &hh1, &mm1, &ss1, &ms1,
62 &hh2, &mm2, &ss2, &ms2, &len) >= 8 && len > 0) {
63 int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
64 int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
65 *duration = end - start;
66 *buf += len;
67 return start;
68 }
69 return AV_NOPTS_VALUE;
70 }
71
stl_read_header(AVFormatContext * s)72 static int stl_read_header(AVFormatContext *s)
73 {
74 STLContext *stl = s->priv_data;
75 AVStream *st = avformat_new_stream(s, NULL);
76
77 if (!st)
78 return AVERROR(ENOMEM);
79 avpriv_set_pts_info(st, 64, 1, 100);
80 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
81 st->codecpar->codec_id = AV_CODEC_ID_STL;
82
83 while (!avio_feof(s->pb)) {
84 char line[4096];
85 char *p = line;
86 const int64_t pos = avio_tell(s->pb);
87 int len = ff_get_line(s->pb, line, sizeof(line));
88 int64_t pts_start;
89 int duration;
90
91 if (!len)
92 break;
93
94 line[strcspn(line, "\r\n")] = 0;
95 pts_start = get_pts(&p , &duration);
96
97 if (pts_start != AV_NOPTS_VALUE) {
98 AVPacket *sub;
99 sub = ff_subtitles_queue_insert(&stl->q, p, strlen(p), 0);
100 if (!sub) {
101 ff_subtitles_queue_clean(&stl->q);
102 return AVERROR(ENOMEM);
103 }
104 sub->pos = pos;
105 sub->pts = pts_start;
106 sub->duration = duration;
107 }
108 }
109 ff_subtitles_queue_finalize(s, &stl->q);
110 return 0;
111 }
stl_read_packet(AVFormatContext * s,AVPacket * pkt)112 static int stl_read_packet(AVFormatContext *s, AVPacket *pkt)
113 {
114 STLContext *stl = s->priv_data;
115 return ff_subtitles_queue_read_packet(&stl->q, pkt);
116 }
117
stl_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)118 static int stl_read_seek(AVFormatContext *s, int stream_index,
119 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
120 {
121 STLContext *stl = s->priv_data;
122 return ff_subtitles_queue_seek(&stl->q, s, stream_index,
123 min_ts, ts, max_ts, flags);
124 }
125
stl_read_close(AVFormatContext * s)126 static int stl_read_close(AVFormatContext *s)
127 {
128 STLContext *stl = s->priv_data;
129 ff_subtitles_queue_clean(&stl->q);
130 return 0;
131 }
132
133 AVInputFormat ff_stl_demuxer = {
134 .name = "stl",
135 .long_name = NULL_IF_CONFIG_SMALL("Spruce subtitle format"),
136 .priv_data_size = sizeof(STLContext),
137 .read_probe = stl_probe,
138 .read_header = stl_read_header,
139 .read_packet = stl_read_packet,
140 .read_seek2 = stl_read_seek,
141 .read_close = stl_read_close,
142 .extensions = "stl",
143 };
144