2 * MicroDVD subtitle demuxer
3 * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4 * Copyright (c) 2012 Clément Bœsch <u pkh me>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "subtitles.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavutil/opt.h"
29 #define MAX_LINESIZE 2048
34 FFDemuxSubtitlesQueue q;
35 AVRational frame_rate;
39 static int microdvd_probe(const AVProbeData *p)
42 const uint8_t *ptr = p->buf;
45 if (AV_RB24(ptr) == 0xEFBBBF)
46 ptr += 3; /* skip UTF-8 BOM */
49 if (sscanf(ptr, "{%*d}{}%c", &c) != 1 &&
50 sscanf(ptr, "{%*d}{%*d}%c", &c) != 1 &&
51 sscanf(ptr, "{DEFAULT}{}%c", &c) != 1)
53 ptr += ff_subtitles_next_line(ptr);
55 return AVPROBE_SCORE_MAX;
58 static int64_t get_pts(const char *buf)
63 if (sscanf(buf, "{%d}{%c", &frame, &c) == 2)
65 return AV_NOPTS_VALUE;
68 static int get_duration(const char *buf)
70 int frame_start, frame_end;
72 if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2)
73 return frame_end - frame_start;
77 static const char *bom = "\xEF\xBB\xBF";
79 static int microdvd_read_header(AVFormatContext *s)
81 AVRational pts_info = (AVRational){ 2997, 125 }; /* default: 23.976 fps */
82 MicroDVDContext *microdvd = s->priv_data;
83 AVStream *st = avformat_new_stream(s, NULL);
85 char line_buf[MAX_LINESIZE];
89 return AVERROR(ENOMEM);
91 while (!avio_feof(s->pb)) {
94 int64_t pos = avio_tell(s->pb);
95 int len = ff_get_line(s->pb, line_buf, sizeof(line_buf));
96 char *line = line_buf;
98 if (!strncmp(line, bom, 3))
104 line[strcspn(line, "\r\n")] = 0;
112 if ((sscanf(line, "{%d}{}%6lf", &frame, &fps) == 2 ||
113 sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2)
114 && frame <= 1 && fps > 3 && fps < 100) {
115 pts_info = av_d2q(fps, 100000);
119 if (!st->codecpar->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {
120 st->codecpar->extradata = av_strdup(line + 11);
121 if (!st->codecpar->extradata)
122 return AVERROR(ENOMEM);
123 st->codecpar->extradata_size = strlen(st->codecpar->extradata) + 1;
127 #define SKIP_FRAME_ID \
128 p = strchr(p, '}'); \
130 av_log(s, AV_LOG_WARNING, "Invalid event \"%s\"" \
131 " at line %d\n", line, i); \
139 sub = ff_subtitles_queue_insert(µdvd->q, p, strlen(p), 0);
141 return AVERROR(ENOMEM);
143 sub->pts = get_pts(line);
144 sub->duration = get_duration(line);
146 ff_subtitles_queue_finalize(s, µdvd->q);
148 /* export the FPS info only if set in the file */
149 microdvd->frame_rate = pts_info;
150 } else if (microdvd->frame_rate.num) {
151 /* fallback on user specified frame rate */
152 pts_info = microdvd->frame_rate;
154 avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
155 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
156 st->codecpar->codec_id = AV_CODEC_ID_MICRODVD;
160 static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
162 MicroDVDContext *microdvd = s->priv_data;
163 return ff_subtitles_queue_read_packet(µdvd->q, pkt);
166 static int microdvd_read_seek(AVFormatContext *s, int stream_index,
167 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
169 MicroDVDContext *microdvd = s->priv_data;
170 return ff_subtitles_queue_seek(µdvd->q, s, stream_index,
171 min_ts, ts, max_ts, flags);
174 static int microdvd_read_close(AVFormatContext *s)
176 MicroDVDContext *microdvd = s->priv_data;
177 ff_subtitles_queue_clean(µdvd->q);
182 #define OFFSET(x) offsetof(MicroDVDContext, x)
183 #define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM
184 static const AVOption microdvd_options[] = {
185 { "subfps", "set the movie frame rate fallback", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, SD },
189 static const AVClass microdvd_class = {
190 .class_name = "microdvddec",
191 .item_name = av_default_item_name,
192 .option = microdvd_options,
193 .version = LIBAVUTIL_VERSION_INT,
196 AVInputFormat ff_microdvd_demuxer = {
198 .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"),
199 .priv_data_size = sizeof(MicroDVDContext),
200 .read_probe = microdvd_probe,
201 .read_header = microdvd_read_header,
202 .read_packet = microdvd_read_packet,
203 .read_seek2 = microdvd_read_seek,
204 .read_close = microdvd_read_close,
205 .priv_class = µdvd_class,