path: root/libavformat/samidec.c (plain)
blob: 7ea1bdfdd97e3166b851c5151bf90d8edd7b3995

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	* SAMI subtitle demuxer
24	* @see http://msdn.microsoft.com/en-us/library/ms971327.aspx
25	*/
26
27	#include "avformat.h"
28	#include "internal.h"
29	#include "subtitles.h"
30	#include "libavcodec/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	} SAMIContext;
38
39	static int sami_probe(AVProbeData *p)
40	{
41	char buf[6];
42	FFTextReader tr;
43	ff_text_init_buf(&tr, p->buf, p->buf_size);
44	ff_text_read(&tr, buf, sizeof(buf));
45
46	return !strncmp(buf, "<SAMI>", 6) ? AVPROBE_SCORE_MAX : 0;
47	}
48
49	static int sami_read_header(AVFormatContext *s)
50	{
51	SAMIContext *sami = s->priv_data;
52	AVStream *st = avformat_new_stream(s, NULL);
53	AVBPrint buf, hdr_buf;
54	char c = 0;
55	int res = 0, got_first_sync_point = 0;
56	FFTextReader tr;
57	ff_text_init_avio(s, &tr, s->pb);
58
59	if (!st)
60	return AVERROR(ENOMEM);
61	avpriv_set_pts_info(st, 64, 1, 1000);
62	st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
63	st->codecpar->codec_id = AV_CODEC_ID_SAMI;
64
65	av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
66	av_bprint_init(&hdr_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
67
68	while (!ff_text_eof(&tr)) {
69	AVPacket *sub;
70	const int64_t pos = ff_text_pos(&tr) - (c != 0);
71	int is_sync, is_body, n = ff_smil_extract_next_text_chunk(&tr, &buf, &c);
72
73	if (n == 0)
74	break;
75
76	is_body = !av_strncasecmp(buf.str, "</BODY", 6);
77	if (is_body) {
78	av_bprint_clear(&buf);
79	break;
80	}
81
82	is_sync = !av_strncasecmp(buf.str, "<SYNC", 5);
83	if (is_sync)
84	got_first_sync_point = 1;
85
86	if (!got_first_sync_point) {
87	av_bprintf(&hdr_buf, "%s", buf.str);
88	} else {
89	sub = ff_subtitles_queue_insert(&sami->q, buf.str, buf.len, !is_sync);
90	if (!sub) {
91	res = AVERROR(ENOMEM);
92	goto end;
93	}
94	if (is_sync) {
95	const char *p = ff_smil_get_attr_ptr(buf.str, "Start");
96	sub->pos = pos;
97	sub->pts = p ? strtol(p, NULL, 10) : 0;
98	sub->duration = -1;
99	}
100	}
101	av_bprint_clear(&buf);
102	}
103
104	res = ff_bprint_to_codecpar_extradata(st->codecpar, &hdr_buf);
105	if (res < 0)
106	goto end;
107
108	ff_subtitles_queue_finalize(s, &sami->q);
109
110	end:
111	av_bprint_finalize(&buf, NULL);
112	return res;
113	}
114
115	static int sami_read_packet(AVFormatContext *s, AVPacket *pkt)
116	{
117	SAMIContext *sami = s->priv_data;
118	return ff_subtitles_queue_read_packet(&sami->q, pkt);
119	}
120
121	static int sami_read_seek(AVFormatContext *s, int stream_index,
122	int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
123	{
124	SAMIContext *sami = s->priv_data;
125	return ff_subtitles_queue_seek(&sami->q, s, stream_index,
126	min_ts, ts, max_ts, flags);
127	}
128
129	static int sami_read_close(AVFormatContext *s)
130	{
131	SAMIContext *sami = s->priv_data;
132	ff_subtitles_queue_clean(&sami->q);
133	return 0;
134	}
135
136	AVInputFormat ff_sami_demuxer = {
137	.name = "sami",
138	.long_name = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
139	.priv_data_size = sizeof(SAMIContext),
140	.read_probe = sami_probe,
141	.read_header = sami_read_header,
142	.read_packet = sami_read_packet,
143	.read_seek2 = sami_read_seek,
144	.read_close = sami_read_close,
145	.extensions = "smi,sami",
146	};
147