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
sami_probe(const AVProbeData * p)39 static int sami_probe(const 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
sami_read_header(AVFormatContext * s)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 av_bprint_finalize(&hdr_buf, NULL);
93 goto end;
94 }
95 if (is_sync) {
96 const char *p = ff_smil_get_attr_ptr(buf.str, "Start");
97 sub->pos = pos;
98 sub->pts = p ? strtol(p, NULL, 10) : 0;
99 if (sub->pts <= INT64_MIN/2 || sub->pts >= INT64_MAX/2) {
100 res = AVERROR_PATCHWELCOME;
101 av_bprint_finalize(&hdr_buf, NULL);
102 goto end;
103 }
104
105 sub->duration = -1;
106 }
107 }
108 av_bprint_clear(&buf);
109 }
110
111 res = ff_bprint_to_codecpar_extradata(st->codecpar, &hdr_buf);
112 if (res < 0)
113 goto end;
114
115 ff_subtitles_queue_finalize(s, &sami->q);
116
117 end:
118 if (res < 0)
119 ff_subtitles_queue_clean(&sami->q);
120 av_bprint_finalize(&buf, NULL);
121 return res;
122 }
123
sami_read_packet(AVFormatContext * s,AVPacket * pkt)124 static int sami_read_packet(AVFormatContext *s, AVPacket *pkt)
125 {
126 SAMIContext *sami = s->priv_data;
127 return ff_subtitles_queue_read_packet(&sami->q, pkt);
128 }
129
sami_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)130 static int sami_read_seek(AVFormatContext *s, int stream_index,
131 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
132 {
133 SAMIContext *sami = s->priv_data;
134 return ff_subtitles_queue_seek(&sami->q, s, stream_index,
135 min_ts, ts, max_ts, flags);
136 }
137
sami_read_close(AVFormatContext * s)138 static int sami_read_close(AVFormatContext *s)
139 {
140 SAMIContext *sami = s->priv_data;
141 ff_subtitles_queue_clean(&sami->q);
142 return 0;
143 }
144
145 AVInputFormat ff_sami_demuxer = {
146 .name = "sami",
147 .long_name = NULL_IF_CONFIG_SMALL("SAMI subtitle format"),
148 .priv_data_size = sizeof(SAMIContext),
149 .read_probe = sami_probe,
150 .read_header = sami_read_header,
151 .read_packet = sami_read_packet,
152 .read_seek2 = sami_read_seek,
153 .read_close = sami_read_close,
154 .extensions = "smi,sami",
155 };
156