2 * SubRip subtitle demuxer
3 * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4 * Copyright (c) 2015 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/bprint.h"
27 #include "libavutil/intreadwrite.h"
30 FFDemuxSubtitlesQueue q;
33 static int srt_probe(AVProbeData *p)
39 ff_text_init_buf(&tr, p->buf, p->buf_size);
41 while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
44 /* Check if the first non-empty line is a number. We do not check what the
45 * number is because in practice it can be anything.
46 * Also, that number can be followed by random garbage, so we can not
47 * unfortunately check that we only have a number. */
48 if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0 ||
49 strtol(buf, &pbuf, 10) < 0 || pbuf == buf)
52 /* Check if the next line matches a SRT timestamp */
53 if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
55 if (buf[0] >= '0' && buf[0] <= '9' && strstr(buf, " --> ")
56 && sscanf(buf, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
57 return AVPROBE_SCORE_MAX;
63 int32_t x1, x2, y1, y2;
69 static int get_event_info(const char *line, struct event_info *ei)
71 int hh1, mm1, ss1, ms1;
72 int hh2, mm2, ss2, ms2;
74 ei->x1 = ei->x2 = ei->y1 = ei->y2 = ei->duration = -1;
75 ei->pts = AV_NOPTS_VALUE;
77 if (sscanf(line, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
78 "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
79 &hh1, &mm1, &ss1, &ms1,
80 &hh2, &mm2, &ss2, &ms2,
81 &ei->x1, &ei->x2, &ei->y1, &ei->y2) >= 8) {
82 const int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
83 const int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
84 ei->duration = end - start;
91 static int add_event(FFDemuxSubtitlesQueue *q, AVBPrint *buf, char *line_cache,
92 const struct event_info *ei, int append_cache)
94 if (append_cache && line_cache[0])
95 av_bprintf(buf, "%s\n", line_cache);
98 while (buf->len > 0 && buf->str[buf->len - 1] == '\n')
99 buf->str[--buf->len] = 0;
102 AVPacket *sub = ff_subtitles_queue_insert(q, buf->str, buf->len, 0);
104 return AVERROR(ENOMEM);
105 av_bprint_clear(buf);
108 sub->duration = ei->duration;
110 uint8_t *p = av_packet_new_side_data(sub, AV_PKT_DATA_SUBTITLE_POSITION, 16);
113 AV_WL32(p + 4, ei->y1);
114 AV_WL32(p + 8, ei->x2);
115 AV_WL32(p + 12, ei->y2);
123 static int srt_read_header(AVFormatContext *s)
125 SRTContext *srt = s->priv_data;
127 AVStream *st = avformat_new_stream(s, NULL);
129 char line[4096], line_cache[4096];
130 int has_event_info = 0;
131 struct event_info ei;
133 ff_text_init_avio(s, &tr, s->pb);
136 return AVERROR(ENOMEM);
137 avpriv_set_pts_info(st, 64, 1, 1000);
138 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
139 st->codec->codec_id = AV_CODEC_ID_SUBRIP;
141 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
145 while (!ff_text_eof(&tr)) {
146 struct event_info tmp_ei;
147 const int64_t pos = ff_text_pos(&tr);
148 ptrdiff_t len = ff_subtitles_read_line(&tr, line, sizeof(line));
153 if (!len || !line[0])
156 if (get_event_info(line, &tmp_ei) < 0) {
163 /* We got some cache and a new line so we assume the cached
164 * line was actually part of the payload */
165 av_bprintf(&buf, "%s\n", line_cache);
169 /* If the line doesn't start with a number, we assume it's part of
170 * the payload, otherwise is likely an event number preceding the
171 * timing information... but we can't be sure of this yet, so we
173 if (strtol(line, &pline, 10) < 0 || line == pline)
174 av_bprintf(&buf, "%s\n", line);
176 strcpy(line_cache, line);
178 if (has_event_info) {
179 /* We have the information of previous event, append it to the
180 * queue. We insert the cached line if and only if the payload
181 * is empty and the cached line is not a standalone number. */
183 const int standalone_number = strtol(line_cache, &pline, 10) >= 0 && pline && !*pline;
184 res = add_event(&srt->q, &buf, line_cache, &ei, !buf.len && !standalone_number);
195 /* Append the last event. Here we force the cache to be flushed, because a
196 * trailing number is more likely to be geniune (for example a copyright
197 * date) and not the event index of an inexistant event */
198 if (has_event_info) {
199 res = add_event(&srt->q, &buf, line_cache, &ei, 1);
204 ff_subtitles_queue_finalize(s, &srt->q);
207 av_bprint_finalize(&buf, NULL);
211 static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
213 SRTContext *srt = s->priv_data;
214 return ff_subtitles_queue_read_packet(&srt->q, pkt);
217 static int srt_read_seek(AVFormatContext *s, int stream_index,
218 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
220 SRTContext *srt = s->priv_data;
221 return ff_subtitles_queue_seek(&srt->q, s, stream_index,
222 min_ts, ts, max_ts, flags);
225 static int srt_read_close(AVFormatContext *s)
227 SRTContext *srt = s->priv_data;
228 ff_subtitles_queue_clean(&srt->q);
232 AVInputFormat ff_srt_demuxer = {
234 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
235 .priv_data_size = sizeof(SRTContext),
236 .read_probe = srt_probe,
237 .read_header = srt_read_header,
238 .read_packet = srt_read_packet,
239 .read_seek2 = srt_read_seek,
240 .read_close = srt_read_close,