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 * MPL2 subtitles format demuxer
24 */
25
26 #include "libavutil/intreadwrite.h"
27
28 #include "avformat.h"
29 #include "internal.h"
30 #include "subtitles.h"
31
32 typedef struct {
33 FFDemuxSubtitlesQueue q;
34 } MPL2Context;
35
mpl2_probe(const AVProbeData * p)36 static int mpl2_probe(const AVProbeData *p)
37 {
38 int i;
39 char c;
40 int64_t start, end;
41 const unsigned char *ptr = p->buf;
42 const unsigned char *ptr_end = ptr + p->buf_size;
43
44 if (AV_RB24(ptr) == 0xefbbbf)
45 ptr += 3;
46
47 for (i = 0; i < 2; i++) {
48 if (sscanf(ptr, "[%"SCNd64"][%"SCNd64"]%c", &start, &end, &c) != 3 &&
49 sscanf(ptr, "[%"SCNd64"][]%c", &start, &c) != 2)
50 return 0;
51 ptr += ff_subtitles_next_line(ptr);
52 if (ptr >= ptr_end)
53 return 0;
54 }
55 return AVPROBE_SCORE_MAX;
56 }
57
read_ts(char ** line,int64_t * pts_start,int64_t * duration)58 static int read_ts(char **line, int64_t *pts_start, int64_t *duration)
59 {
60 char c;
61 int len;
62 int64_t end;
63
64 if (sscanf(*line, "[%"SCNd64"][]%c%n",
65 pts_start, &c, &len) >= 2) {
66 *duration = -1;
67 *line += len - 1;
68 return 0;
69 }
70 if (sscanf(*line, "[%"SCNd64"][%"SCNd64"]%c%n",
71 pts_start, &end, &c, &len) >= 3) {
72 if (end < *pts_start || end - (uint64_t)*pts_start > INT64_MAX) {
73 *duration = -1;
74 } else
75 *duration = end - *pts_start;
76 *line += len - 1;
77 return 0;
78 }
79 return -1;
80 }
81
mpl2_read_header(AVFormatContext * s)82 static int mpl2_read_header(AVFormatContext *s)
83 {
84 MPL2Context *mpl2 = s->priv_data;
85 AVStream *st = avformat_new_stream(s, NULL);
86
87 if (!st)
88 return AVERROR(ENOMEM);
89 avpriv_set_pts_info(st, 64, 1, 10);
90 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
91 st->codecpar->codec_id = AV_CODEC_ID_MPL2;
92
93 if (avio_rb24(s->pb) != 0xefbbbf)
94 avio_seek(s->pb, -3, SEEK_CUR);
95
96 while (!avio_feof(s->pb)) {
97 char line[4096];
98 char *p = line;
99 const int64_t pos = avio_tell(s->pb);
100 int len = ff_get_line(s->pb, line, sizeof(line));
101 int64_t pts_start;
102 int64_t duration;
103
104 if (!len)
105 break;
106
107 line[strcspn(line, "\r\n")] = 0;
108
109 if (!read_ts(&p, &pts_start, &duration)) {
110 AVPacket *sub;
111
112 sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
113 if (!sub) {
114 ff_subtitles_queue_clean(&mpl2->q);
115 return AVERROR(ENOMEM);
116 }
117 sub->pos = pos;
118 sub->pts = pts_start;
119 sub->duration = duration;
120 }
121 }
122
123 ff_subtitles_queue_finalize(s, &mpl2->q);
124 return 0;
125 }
126
mpl2_read_packet(AVFormatContext * s,AVPacket * pkt)127 static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)
128 {
129 MPL2Context *mpl2 = s->priv_data;
130 return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
131 }
132
mpl2_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)133 static int mpl2_read_seek(AVFormatContext *s, int stream_index,
134 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
135 {
136 MPL2Context *mpl2 = s->priv_data;
137 return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
138 min_ts, ts, max_ts, flags);
139 }
140
mpl2_read_close(AVFormatContext * s)141 static int mpl2_read_close(AVFormatContext *s)
142 {
143 MPL2Context *mpl2 = s->priv_data;
144 ff_subtitles_queue_clean(&mpl2->q);
145 return 0;
146 }
147
148 AVInputFormat ff_mpl2_demuxer = {
149 .name = "mpl2",
150 .long_name = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
151 .priv_data_size = sizeof(MPL2Context),
152 .read_probe = mpl2_probe,
153 .read_header = mpl2_read_header,
154 .read_packet = mpl2_read_packet,
155 .read_seek2 = mpl2_read_seek,
156 .read_close = mpl2_read_close,
157 .extensions = "txt,mpl2",
158 };
159