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 "libavutil/avstring.h"
31 #include "libavutil/bprint.h"
32
33 typedef struct {
34 FFDemuxSubtitlesQueue q;
35 } SAMIContext;
36
sami_probe(const AVProbeData * p)37 static int sami_probe(const AVProbeData *p)
38 {
39 char buf[6];
40 FFTextReader tr;
41 ff_text_init_buf(&tr, p->buf, p->buf_size);
42 ff_text_read(&tr, buf, sizeof(buf));
43
44 return !strncmp(buf, "<SAMI>", 6) ? AVPROBE_SCORE_MAX : 0;
45 }
46
sami_read_header(AVFormatContext * s)47 static int sami_read_header(AVFormatContext *s)
48 {
49 SAMIContext *sami = s->priv_data;
50 AVStream *st = avformat_new_stream(s, NULL);
51 AVBPrint buf, hdr_buf;
52 char c = 0;
53 int res = 0, got_first_sync_point = 0;
54 FFTextReader tr;
55 ff_text_init_avio(s, &tr, s->pb);
56
57 if (!st)
58 return AVERROR(ENOMEM);
59 avpriv_set_pts_info(st, 64, 1, 1000);
60 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
61 st->codecpar->codec_id = AV_CODEC_ID_SAMI;
62
63 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
64 av_bprint_init(&hdr_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
65
66 while (!ff_text_eof(&tr)) {
67 AVPacket *sub;
68 const int64_t pos = ff_text_pos(&tr) - (c != 0);
69 int is_sync, is_body, n = ff_smil_extract_next_text_chunk(&tr, &buf, &c);
70
71 if (n == 0)
72 break;
73
74 is_body = !av_strncasecmp(buf.str, "</BODY", 6);
75 if (is_body) {
76 av_bprint_clear(&buf);
77 break;
78 }
79
80 is_sync = !av_strncasecmp(buf.str, "<SYNC", 5);
81 if (is_sync)
82 got_first_sync_point = 1;
83
84 if (!got_first_sync_point) {
85 av_bprintf(&hdr_buf, "%s", buf.str);
86 } else {
87 sub = ff_subtitles_queue_insert(&sami->q, buf.str, buf.len, !is_sync);
88 if (!sub) {
89 res = AVERROR(ENOMEM);
90 av_bprint_finalize(&hdr_buf, NULL);
91 goto end;
92 }
93 if (is_sync) {
94 const char *p = ff_smil_get_attr_ptr(buf.str, "Start");
95 sub->pos = pos;
96 sub->pts = p ? strtol(p, NULL, 10) : 0;
97 if (sub->pts <= INT64_MIN/2 || sub->pts >= INT64_MAX/2) {
98 res = AVERROR_PATCHWELCOME;
99 av_bprint_finalize(&hdr_buf, NULL);
100 goto end;
101 }
102
103 sub->duration = -1;
104 }
105 }
106 av_bprint_clear(&buf);
107 }
108
109 res = ff_bprint_to_codecpar_extradata(st->codecpar, &hdr_buf);
110 if (res < 0)
111 goto end;
112
113 ff_subtitles_queue_finalize(s, &sami->q);
114
115 end:
116 av_bprint_finalize(&buf, NULL);
117 return res;
118 }
119
120 const AVInputFormat ff_sami_demuxer = {
121 .name = "sami",
122 .long_name = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
123 .priv_data_size = sizeof(SAMIContext),
124 .flags_internal = FF_FMT_INIT_CLEANUP,
125 .read_probe = sami_probe,
126 .read_header = sami_read_header,
127 .extensions = "smi,sami",
128 .read_packet = ff_subtitles_read_packet,
129 .read_seek2 = ff_subtitles_read_seek,
130 .read_close = ff_subtitles_read_close,
131 };
132