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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  * AQTitle subtitles format demuxer
24  *
25  * @see http://web.archive.org/web/20070210095721/http://www.volny.cz/aberka/czech/aqt.html
26  * @see https://trac.annodex.net/wiki/AQTitle
27  */
28 
29 #include "avformat.h"
30 #include "internal.h"
31 #include "subtitles.h"
32 #include "libavutil/opt.h"
33 
34 typedef struct {
35     const AVClass *class;
36     FFDemuxSubtitlesQueue q;
37     AVRational frame_rate;
38 } AQTitleContext;
39 
aqt_probe(const AVProbeData * p)40 static int aqt_probe(const AVProbeData *p)
41 {
42     int frame;
43     const char *ptr = p->buf;
44 
45     if (sscanf(ptr, "-->> %d", &frame) == 1)
46         return AVPROBE_SCORE_EXTENSION;
47     return 0;
48 }
49 
aqt_read_header(AVFormatContext * s)50 static int aqt_read_header(AVFormatContext *s)
51 {
52     AQTitleContext *aqt = s->priv_data;
53     AVStream *st = avformat_new_stream(s, NULL);
54     int new_event = 1;
55     int64_t pos = 0, frame = AV_NOPTS_VALUE;
56     AVPacket *sub = NULL;
57 
58     if (!st)
59         return AVERROR(ENOMEM);
60     avpriv_set_pts_info(st, 64, aqt->frame_rate.den, aqt->frame_rate.num);
61     st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
62     st->codecpar->codec_id   = AV_CODEC_ID_TEXT;
63 
64     while (!avio_feof(s->pb)) {
65         char line[4096];
66         int len = ff_get_line(s->pb, line, sizeof(line));
67 
68         if (!len)
69             break;
70 
71         line[strcspn(line, "\r\n")] = 0;
72 
73         if (sscanf(line, "-->> %"SCNd64, &frame) == 1) {
74             new_event = 1;
75             pos = avio_tell(s->pb);
76             if (sub) {
77                 sub->duration = frame - sub->pts;
78                 sub = NULL;
79             }
80         } else if (*line) {
81             if (!new_event) {
82                 sub = ff_subtitles_queue_insert(&aqt->q, "\n", 1, 1);
83                 if (!sub)
84                     goto fail;
85             }
86             sub = ff_subtitles_queue_insert(&aqt->q, line, strlen(line), !new_event);
87             if (!sub)
88                 goto fail;
89             if (new_event) {
90                 sub->pts = frame;
91                 sub->duration = -1;
92                 sub->pos = pos;
93             }
94             new_event = 0;
95         }
96     }
97 
98     ff_subtitles_queue_finalize(s, &aqt->q);
99     return 0;
100 fail:
101     ff_subtitles_queue_clean(&aqt->q);
102     return AVERROR(ENOMEM);
103 }
104 
aqt_read_packet(AVFormatContext * s,AVPacket * pkt)105 static int aqt_read_packet(AVFormatContext *s, AVPacket *pkt)
106 {
107     AQTitleContext *aqt = s->priv_data;
108     return ff_subtitles_queue_read_packet(&aqt->q, pkt);
109 }
110 
aqt_read_seek(AVFormatContext * s,int stream_index,int64_t min_ts,int64_t ts,int64_t max_ts,int flags)111 static int aqt_read_seek(AVFormatContext *s, int stream_index,
112                          int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
113 {
114     AQTitleContext *aqt = s->priv_data;
115     return ff_subtitles_queue_seek(&aqt->q, s, stream_index,
116                                    min_ts, ts, max_ts, flags);
117 }
118 
aqt_read_close(AVFormatContext * s)119 static int aqt_read_close(AVFormatContext *s)
120 {
121     AQTitleContext *aqt = s->priv_data;
122     ff_subtitles_queue_clean(&aqt->q);
123     return 0;
124 }
125 
126 #define OFFSET(x) offsetof(AQTitleContext, x)
127 #define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM
128 static const AVOption aqt_options[] = {
129     { "subfps", "set the movie frame rate", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=25}, 0, INT_MAX, SD },
130     { NULL }
131 };
132 
133 static const AVClass aqt_class = {
134     .class_name = "aqtdec",
135     .item_name  = av_default_item_name,
136     .option     = aqt_options,
137     .version    = LIBAVUTIL_VERSION_INT,
138 };
139 
140 AVInputFormat ff_aqtitle_demuxer = {
141     .name           = "aqtitle",
142     .long_name      = NULL_IF_CONFIG_SMALL("AQTitle subtitles"),
143     .priv_data_size = sizeof(AQTitleContext),
144     .read_probe     = aqt_probe,
145     .read_header    = aqt_read_header,
146     .read_packet    = aqt_read_packet,
147     .read_seek2     = aqt_read_seek,
148     .read_close     = aqt_read_close,
149     .extensions     = "aqt",
150     .priv_class     = &aqt_class,
151 };
152