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stldec.c
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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 {
35 } STLContext;
36 
37 static int stl_probe(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 
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 
73 {
74  STLContext *stl = s->priv_data;
76 
77  if (!st)
78  return AVERROR(ENOMEM);
79  avpriv_set_pts_info(st, 64, 1, 100);
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  return AVERROR(ENOMEM);
102  sub->pos = pos;
103  sub->pts = pts_start;
104  sub->duration = duration;
105  }
106  }
108  return 0;
109 }
111 {
112  STLContext *stl = s->priv_data;
113  return ff_subtitles_queue_read_packet(&stl->q, pkt);
114 }
115 
116 static int stl_read_seek(AVFormatContext *s, int stream_index,
117  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
118 {
119  STLContext *stl = s->priv_data;
120  return ff_subtitles_queue_seek(&stl->q, s, stream_index,
121  min_ts, ts, max_ts, flags);
122 }
123 
125 {
126  STLContext *stl = s->priv_data;
128  return 0;
129 }
130 
132  .name = "stl",
133  .long_name = NULL_IF_CONFIG_SMALL("Spruce subtitle format"),
134  .priv_data_size = sizeof(STLContext),
138  .read_seek2 = stl_read_seek,
140  .extensions = "stl",
141 };