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 * MPlayer subtitles format demuxer
24 */
25
26 #include "avformat.h"
27 #include "internal.h"
28 #include "subtitles.h"
29
30 #define TSBASE 10000000
31
32 typedef struct {
33 FFDemuxSubtitlesQueue q;
34 } MPSubContext;
35
mpsub_probe(const AVProbeData * p)36 static int mpsub_probe(const AVProbeData *p)
37 {
38 const char *ptr = p->buf;
39 const char *ptr_end = p->buf + p->buf_size;
40
41 while (ptr < ptr_end) {
42 int inc;
43
44 if (!memcmp(ptr, "FORMAT=TIME", 11))
45 return AVPROBE_SCORE_EXTENSION;
46 if (!memcmp(ptr, "FORMAT=", 7))
47 return AVPROBE_SCORE_EXTENSION / 3;
48 inc = ff_subtitles_next_line(ptr);
49 if (!inc)
50 break;
51 ptr += inc;
52 }
53 return 0;
54 }
55
parse_line(const char * line,int64_t * value,int64_t * value2)56 static int parse_line(const char *line, int64_t *value, int64_t *value2)
57 {
58 int vi, p1, p2;
59
60 for (vi = 0; vi < 2; vi++) {
61 long long intval, fracval;
62 int n = av_sscanf(line, "%lld%n.%lld%n", &intval, &p1, &fracval, &p2);
63 if (n <= 0 || intval < INT64_MIN / TSBASE || intval > INT64_MAX / TSBASE)
64 return AVERROR_INVALIDDATA;
65
66 intval *= TSBASE;
67
68 if (n == 2) {
69 if (fracval < 0)
70 return AVERROR_INVALIDDATA;
71 for (;p2 - p1 < 7 + 1; p1--)
72 fracval *= 10;
73 for (;p2 - p1 > 7 + 1; p1++)
74 fracval /= 10;
75 if (intval > 0) intval = av_sat_add64(intval, fracval);
76 else intval = av_sat_sub64(intval, fracval);
77 line += p2;
78 } else
79 line += p1;
80
81 *value = intval;
82
83 value = value2;
84 }
85
86 return 0;
87 }
88
mpsub_read_header(AVFormatContext * s)89 static int mpsub_read_header(AVFormatContext *s)
90 {
91 MPSubContext *mpsub = s->priv_data;
92 AVStream *st;
93 AVBPrint buf;
94 AVRational pts_info = (AVRational){ TSBASE, 1 }; // ts based by default
95 int res = 0;
96 int64_t current_pts = 0;
97 int i;
98 int common_factor = 0;
99
100 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
101
102 while (!avio_feof(s->pb)) {
103 char line[1024];
104 int64_t start, duration;
105 int fps, len = ff_get_line(s->pb, line, sizeof(line));
106
107 if (!len)
108 break;
109
110 line[strcspn(line, "\r\n")] = 0;
111
112 if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) {
113 /* frame based timing */
114 pts_info = (AVRational){ TSBASE * fps, 1 };
115 } else if (parse_line(line, &start, &duration) >= 0) {
116 AVPacket *sub;
117 const int64_t pos = avio_tell(s->pb);
118
119 ff_subtitles_read_chunk(s->pb, &buf);
120 if (buf.len) {
121 sub = ff_subtitles_queue_insert(&mpsub->q, buf.str, buf.len, 0);
122 if (!sub) {
123 res = AVERROR(ENOMEM);
124 goto end;
125 }
126 if ( current_pts < 0 && start < INT64_MIN - current_pts
127 || current_pts > 0 && start > INT64_MAX - current_pts) {
128 res = AVERROR_INVALIDDATA;
129 goto end;
130 }
131 sub->pts = current_pts + start;
132 if (duration < 0 || sub->pts > INT64_MAX - duration) {
133 res = AVERROR_INVALIDDATA;
134 goto end;
135 }
136 sub->duration = duration;
137
138 common_factor = av_gcd(duration, common_factor);
139 common_factor = av_gcd(sub->pts, common_factor);
140
141 current_pts = sub->pts + duration;
142 sub->pos = pos;
143 }
144 }
145 }
146
147 if (common_factor > 1) {
148 common_factor = av_gcd(pts_info.num, common_factor);
149 for (i = 0; i < mpsub->q.nb_subs; i++) {
150 mpsub->q.subs[i]->pts /= common_factor;
151 mpsub->q.subs[i]->duration /= common_factor;
152 }
153 pts_info.num /= common_factor;
154 }
155
156 st = avformat_new_stream(s, NULL);
157 if (!st) {
158 res = AVERROR(ENOMEM);
159 goto end;
160 }
161 avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
162 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
163 st->codecpar->codec_id = AV_CODEC_ID_TEXT;
164
165 ff_subtitles_queue_finalize(s, &mpsub->q);
166
167 end:
168 if (res < 0)
169 ff_subtitles_queue_clean(&mpsub->q);
170
171 av_bprint_finalize(&buf, NULL);
172 return res;
173 }
174
mpsub_read_packet(AVFormatContext * s,AVPacket * pkt)175 static int mpsub_read_packet(AVFormatContext *s, AVPacket *pkt)
176 {
177 MPSubContext *mpsub = s->priv_data;
178 return ff_subtitles_queue_read_packet(&mpsub->q, pkt);
179 }
180
mpsub_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)181 static int mpsub_read_seek(AVFormatContext *s, int stream_index,
182 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
183 {
184 MPSubContext *mpsub = s->priv_data;
185 return ff_subtitles_queue_seek(&mpsub->q, s, stream_index,
186 min_ts, ts, max_ts, flags);
187 }
188
mpsub_read_close(AVFormatContext * s)189 static int mpsub_read_close(AVFormatContext *s)
190 {
191 MPSubContext *mpsub = s->priv_data;
192 ff_subtitles_queue_clean(&mpsub->q);
193 return 0;
194 }
195
196 AVInputFormat ff_mpsub_demuxer = {
197 .name = "mpsub",
198 .long_name = NULL_IF_CONFIG_SMALL("MPlayer subtitles"),
199 .priv_data_size = sizeof(MPSubContext),
200 .read_probe = mpsub_probe,
201 .read_header = mpsub_read_header,
202 .read_packet = mpsub_read_packet,
203 .read_seek2 = mpsub_read_seek,
204 .read_close = mpsub_read_close,
205 .extensions = "sub",
206 };
207