1/*
2 * Copyright (c) 2012 Cl��ment B��sch
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#ifndef AVFORMAT_SUBTITLES_H
22#define AVFORMAT_SUBTITLES_H
23
24#include <stdint.h>
25#include "avformat.h"
26#include "libavutil/bprint.h"
27
28enum sub_sort {
29    SUB_SORT_TS_POS = 0,    ///< sort by timestamps, then position
30    SUB_SORT_POS_TS,        ///< sort by position, then timestamps
31};
32
33typedef struct {
34    AVPacket *subs;         ///< array of subtitles packets
35    int nb_subs;            ///< number of subtitles packets
36    int allocated_size;     ///< allocated size for subs
37    int current_sub_idx;    ///< current position for the read packet callback
38    enum sub_sort sort;     ///< sort method to use when finalizing subtitles
39} FFDemuxSubtitlesQueue;
40
41/**
42 * Insert a new subtitle event.
43 *
44 * @param event the subtitle line, may not be zero terminated
45 * @param len   the length of the event (in strlen() sense, so without '\0')
46 * @param merge set to 1 if the current event should be concatenated with the
47 *              previous one instead of adding a new entry, 0 otherwise
48 */
49AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
50                                    const uint8_t *event, int len, int merge);
51
52/**
53 * Set missing durations and sort subtitles by PTS, and then byte position.
54 */
55void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q);
56
57/**
58 * Generic read_packet() callback for subtitles demuxers using this queue
59 * system.
60 */
61int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt);
62
63/**
64 * Update current_sub_idx to emulate a seek. Except the first parameter, it
65 * matches AVInputFormat->read_seek2 prototypes.
66 */
67int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index,
68                            int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
69
70/**
71 * Remove and destroy all the subtitles packets.
72 */
73void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q);
74
75/**
76 * SMIL helper to load next chunk ("<...>" or untagged content) in buf.
77 *
78 * @param c cached character, to avoid a backward seek
79 */
80int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c);
81
82/**
83 * SMIL helper to point on the value of an attribute in the given tag.
84 *
85 * @param s    SMIL tag ("<...>")
86 * @param attr the attribute to look for
87 */
88const char *ff_smil_get_attr_ptr(const char *s, const char *attr);
89
90/**
91 * @brief Read a subtitles chunk.
92 *
93 * A chunk is defined by a multiline "event", ending with a second line break.
94 * The trailing line breaks are trimmed. CRLF are supported.
95 * Example: "foo\r\nbar\r\n\r\nnext" will print "foo\r\nbar" into buf, and pb
96 * will focus on the 'n' of the "next" string.
97 *
98 * @param pb  I/O context
99 * @param buf an initialized buf where the chunk is written
100 *
101 * @note buf is cleared before writing into it.
102 */
103void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf);
104
105/**
106 * Get the number of characters to increment to jump to the next line, or to
107 * the end of the string.
108 * The function handles the following line breaks schemes:
109 * LF, CRLF (MS), or standalone CR (old MacOS).
110 */
111static av_always_inline int ff_subtitles_next_line(const char *ptr)
112{
113    int n = strcspn(ptr, "\r\n");
114    ptr += n;
115    if (*ptr == '\r') {
116        ptr++;
117        n++;
118    }
119    if (*ptr == '\n')
120        n++;
121    return n;
122}
123
124#endif /* AVFORMAT_SUBTITLES_H */
125