1 /*
2 * Copyright (c) 2012 Clément Bœsch
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 * SubViewer subtitle demuxer
24 * @see https://en.wikipedia.org/wiki/SubViewer
25 */
26
27 #include "avformat.h"
28 #include "internal.h"
29 #include "subtitles.h"
30 #include "avio_internal.h"
31 #include "libavutil/avstring.h"
32 #include "libavutil/bprint.h"
33 #include "libavutil/intreadwrite.h"
34
35 typedef struct {
36 FFDemuxSubtitlesQueue q;
37 } SubViewerContext;
38
subviewer_probe(const AVProbeData * p)39 static int subviewer_probe(const AVProbeData *p)
40 {
41 char c;
42 const unsigned char *ptr = p->buf;
43
44 if (AV_RB24(ptr) == 0xEFBBBF)
45 ptr += 3; /* skip UTF-8 BOM */
46 if (sscanf(ptr, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
47 return AVPROBE_SCORE_EXTENSION;
48 if (!strncmp(ptr, "[INFORMATION]", 13))
49 return AVPROBE_SCORE_MAX/3;
50 return 0;
51 }
52
get_multiplier(int e)53 static int get_multiplier(int e) {
54 switch (e) {
55 case 1 : return 100;
56 case 2 : return 10;
57 case 3 : return 1;
58 default : return -1;
59 }
60 }
61
read_ts(const char * s,int64_t * start,int * duration)62 static int read_ts(const char *s, int64_t *start, int *duration)
63 {
64 int64_t end;
65 int hh1, mm1, ss1, ms1;
66 int hh2, mm2, ss2, ms2;
67 int multiplier1, multiplier2;
68 int ms1p1, ms1p2, ms2p1, ms2p2;
69
70 if (sscanf(s, "%u:%u:%u.%n%u%n,%u:%u:%u.%n%u%n",
71 &hh1, &mm1, &ss1, &ms1p1, &ms1, &ms1p2, &hh2, &mm2, &ss2, &ms2p1, &ms2, &ms2p2) == 8) {
72 multiplier1 = get_multiplier(ms1p2 - ms1p1);
73 multiplier2 = get_multiplier(ms2p2 - ms2p1);
74 if (multiplier1 <= 0 ||multiplier2 <= 0)
75 return -1;
76
77 end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2 * multiplier2;
78 *start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1 * multiplier1;
79 *duration = end - *start;
80 return 0;
81 }
82 return -1;
83 }
84
subviewer_read_header(AVFormatContext * s)85 static int subviewer_read_header(AVFormatContext *s)
86 {
87 SubViewerContext *subviewer = s->priv_data;
88 AVStream *st = avformat_new_stream(s, NULL);
89 AVBPrint header;
90 int res = 0, new_event = 1;
91 int64_t pts_start = AV_NOPTS_VALUE;
92 int duration = -1;
93 AVPacket *sub = NULL;
94
95 if (!st)
96 return AVERROR(ENOMEM);
97 res = ffio_ensure_seekback(s->pb, 3);
98 if (res < 0)
99 return res;
100 if (avio_rb24(s->pb) != 0xefbbbf)
101 avio_seek(s->pb, -3, SEEK_CUR);
102 avpriv_set_pts_info(st, 64, 1, 1000);
103 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
104 st->codecpar->codec_id = AV_CODEC_ID_SUBVIEWER;
105
106 av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
107
108 while (!avio_feof(s->pb)) {
109 char line[2048];
110 int64_t pos = 0;
111 int len = ff_get_line(s->pb, line, sizeof(line));
112
113 if (!len)
114 break;
115
116 line[strcspn(line, "\r\n")] = 0;
117
118 if (line[0] == '[' && strncmp(line, "[br]", 4)) {
119
120 /* ignore event style, XXX: add to side_data? */
121 if (strstr(line, "[COLF]") || strstr(line, "[SIZE]") ||
122 strstr(line, "[FONT]") || strstr(line, "[STYLE]"))
123 continue;
124
125 if (!st->codecpar->extradata) { // header not finalized yet
126 av_bprintf(&header, "%s\n", line);
127 if (!strncmp(line, "[END INFORMATION]", 17) || !strncmp(line, "[SUBTITLE]", 10)) {
128 /* end of header */
129 res = ff_bprint_to_codecpar_extradata(st->codecpar, &header);
130 if (res < 0)
131 goto end;
132 } else if (strncmp(line, "[INFORMATION]", 13)) {
133 /* assume file metadata at this point */
134 int i, j = 0;
135 char key[32], value[128];
136
137 for (i = 1; i < sizeof(key) - 1 && line[i] && line[i] != ']'; i++)
138 key[i - 1] = av_tolower(line[i]);
139 key[i - 1] = 0;
140
141 if (line[i] == ']')
142 i++;
143 while (line[i] == ' ')
144 i++;
145 while (j < sizeof(value) - 1 && line[i] && line[i] != ']')
146 value[j++] = line[i++];
147 value[j] = 0;
148
149 av_dict_set(&s->metadata, key, value, 0);
150 }
151 }
152 } else if (read_ts(line, &pts_start, &duration) >= 0) {
153 new_event = 1;
154 pos = avio_tell(s->pb);
155 } else if (*line) {
156 if (pts_start == AV_NOPTS_VALUE) {
157 res = AVERROR_INVALIDDATA;
158 goto end;
159 }
160 if (!new_event) {
161 sub = ff_subtitles_queue_insert(&subviewer->q, "\n", 1, 1);
162 if (!sub) {
163 res = AVERROR(ENOMEM);
164 goto end;
165 }
166 }
167 sub = ff_subtitles_queue_insert(&subviewer->q, line, strlen(line), !new_event);
168 if (!sub) {
169 res = AVERROR(ENOMEM);
170 goto end;
171 }
172 if (new_event) {
173 sub->pos = pos;
174 sub->pts = pts_start;
175 sub->duration = duration;
176 }
177 new_event = 0;
178 }
179 }
180
181 ff_subtitles_queue_finalize(s, &subviewer->q);
182
183 end:
184 av_bprint_finalize(&header, NULL);
185 return res;
186 }
187
188 const AVInputFormat ff_subviewer_demuxer = {
189 .name = "subviewer",
190 .long_name = NULL_IF_CONFIG_SMALL("SubViewer subtitle format"),
191 .priv_data_size = sizeof(SubViewerContext),
192 .flags_internal = FF_FMT_INIT_CLEANUP,
193 .read_probe = subviewer_probe,
194 .read_header = subviewer_read_header,
195 .extensions = "sub",
196 .read_packet = ff_subtitles_read_packet,
197 .read_seek2 = ff_subtitles_read_seek,
198 .read_close = ff_subtitles_read_close,
199 };
200