path: root/libavformat/mpl2dec.c (plain)
blob: dfcdf5a5645a7c6c881bead6f0435bef68051fa7

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
36	static int mpl2_probe(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
58	static int read_ts(char **line, int64_t *pts_start, int *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	*duration = end - *pts_start;
73	*line += len - 1;
74	return 0;
75	}
76	return -1;
77	}
78
79	static int mpl2_read_header(AVFormatContext *s)
80	{
81	MPL2Context *mpl2 = s->priv_data;
82	AVStream *st = avformat_new_stream(s, NULL);
83	int res = 0;
84
85	if (!st)
86	return AVERROR(ENOMEM);
87	avpriv_set_pts_info(st, 64, 1, 10);
88	st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
89	st->codecpar->codec_id = AV_CODEC_ID_MPL2;
90
91	if (avio_rb24(s->pb) != 0xefbbbf)
92	avio_seek(s->pb, -3, SEEK_CUR);
93
94	while (!avio_feof(s->pb)) {
95	char line[4096];
96	char *p = line;
97	const int64_t pos = avio_tell(s->pb);
98	int len = ff_get_line(s->pb, line, sizeof(line));
99	int64_t pts_start;
100	int duration;
101
102	if (!len)
103	break;
104
105	line[strcspn(line, "\r\n")] = 0;
106
107	if (!read_ts(&p, &pts_start, &duration)) {
108	AVPacket *sub;
109
110	sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
111	if (!sub)
112	return AVERROR(ENOMEM);
113	sub->pos = pos;
114	sub->pts = pts_start;
115	sub->duration = duration;
116	}
117	}
118
119	ff_subtitles_queue_finalize(s, &mpl2->q);
120	return res;
121	}
122
123	static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)
124	{
125	MPL2Context *mpl2 = s->priv_data;
126	return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
127	}
128
129	static int mpl2_read_seek(AVFormatContext *s, int stream_index,
130	int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
131	{
132	MPL2Context *mpl2 = s->priv_data;
133	return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
134	min_ts, ts, max_ts, flags);
135	}
136
137	static int mpl2_read_close(AVFormatContext *s)
138	{
139	MPL2Context *mpl2 = s->priv_data;
140	ff_subtitles_queue_clean(&mpl2->q);
141	return 0;
142	}
143
144	AVInputFormat ff_mpl2_demuxer = {
145	.name = "mpl2",
146	.long_name = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
147	.priv_data_size = sizeof(MPL2Context),
148	.read_probe = mpl2_probe,
149	.read_header = mpl2_read_header,
150	.read_packet = mpl2_read_packet,
151	.read_seek2 = mpl2_read_seek,
152	.read_close = mpl2_read_close,
153	.extensions = "txt,mpl2",
154	};
155