2 * Copyright (c) 2012 Clément Bœsch
4 * This file is part of FFmpeg.
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.
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.
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
21 #ifndef AVFORMAT_SUBTITLES_H
22 #define AVFORMAT_SUBTITLES_H
27 #include "libavutil/bprint.h"
30 SUB_SORT_TS_POS
= 0, ///< sort by timestamps, then position
31 SUB_SORT_POS_TS
, ///< sort by position, then timestamps
35 FF_UTF_8
, // or other 8 bit encodings
49 * Initialize the FFTextReader from the given AVIOContext. This function will
50 * read some bytes from pb, and test for UTF-8 or UTF-16 BOMs. Further accesses
51 * to FFTextReader will read more data from pb.
52 * If s is not NULL, the user will be warned if a UTF-16 conversion takes place.
54 * The purpose of FFTextReader is to transparently convert read data to UTF-8
55 * if the stream had a UTF-16 BOM.
57 * @param s Pointer to provide av_log context
58 * @param r object which will be initialized
59 * @param pb stream to read from (referenced as long as FFTextReader is in use)
61 void ff_text_init_avio(void *s
, FFTextReader
*r
, AVIOContext
*pb
);
64 * Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer.
66 * @param r object which will be initialized
67 * @param buf buffer to read from (referenced as long as FFTextReader is in use)
68 * @param size size of buf
70 void ff_text_init_buf(FFTextReader
*r
, void *buf
, size_t size
);
73 * Return the byte position of the next byte returned by ff_text_r8(). For
74 * UTF-16 source streams, this will return the original position, but it will
75 * be incorrect if a codepoint was only partially read with ff_text_r8().
77 int64_t ff_text_pos(FFTextReader
*r
);
80 * Return the next byte. The return value is always 0 - 255. Returns 0 on EOF.
81 * If the source stream is UTF-16, this reads from the stream converted to
82 * UTF-8. On invalid UTF-16, 0 is returned.
84 int ff_text_r8(FFTextReader
*r
);
87 * Return non-zero if EOF was reached.
89 int ff_text_eof(FFTextReader
*r
);
92 * Like ff_text_r8(), but don't remove the byte from the buffer.
94 int ff_text_peek_r8(FFTextReader
*r
);
97 * Read the given number of bytes (in UTF-8). On error or EOF, \0 bytes are
100 void ff_text_read(FFTextReader
*r
, char *buf
, size_t size
);
103 AVPacket
*subs
; ///< array of subtitles packets
104 int nb_subs
; ///< number of subtitles packets
105 int allocated_size
; ///< allocated size for subs
106 int current_sub_idx
; ///< current position for the read packet callback
107 enum sub_sort sort
; ///< sort method to use when finalizing subtitles
108 } FFDemuxSubtitlesQueue
;
111 * Insert a new subtitle event.
113 * @param event the subtitle line, may not be zero terminated
114 * @param len the length of the event (in strlen() sense, so without '\0')
115 * @param merge set to 1 if the current event should be concatenated with the
116 * previous one instead of adding a new entry, 0 otherwise
118 AVPacket
*ff_subtitles_queue_insert(FFDemuxSubtitlesQueue
*q
,
119 const uint8_t *event
, int len
, int merge
);
122 * Set missing durations and sort subtitles by PTS, and then byte position.
124 void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue
*q
);
127 * Generic read_packet() callback for subtitles demuxers using this queue
130 int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue
*q
, AVPacket
*pkt
);
133 * Update current_sub_idx to emulate a seek. Except the first parameter, it
134 * matches AVInputFormat->read_seek2 prototypes.
136 int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue
*q
, AVFormatContext
*s
, int stream_index
,
137 int64_t min_ts
, int64_t ts
, int64_t max_ts
, int flags
);
140 * Remove and destroy all the subtitles packets.
142 void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue
*q
);
145 * SMIL helper to load next chunk ("<...>" or untagged content) in buf.
147 * @param c cached character, to avoid a backward seek
149 int ff_smil_extract_next_text_chunk(FFTextReader
*tr
, AVBPrint
*buf
, char *c
);
152 * SMIL helper to point on the value of an attribute in the given tag.
154 * @param s SMIL tag ("<...>")
155 * @param attr the attribute to look for
157 const char *ff_smil_get_attr_ptr(const char *s
, const char *attr
);
160 * @brief Same as ff_subtitles_read_text_chunk(), but read from an AVIOContext.
162 void ff_subtitles_read_chunk(AVIOContext
*pb
, AVBPrint
*buf
);
165 * @brief Read a subtitles chunk from FFTextReader.
167 * A chunk is defined by a multiline "event", ending with a second line break.
168 * The trailing line breaks are trimmed. CRLF are supported.
169 * Example: "foo\r\nbar\r\n\r\nnext" will print "foo\r\nbar" into buf, and pb
170 * will focus on the 'n' of the "next" string.
172 * @param tr I/O context
173 * @param buf an initialized buf where the chunk is written
175 * @note buf is cleared before writing into it.
177 void ff_subtitles_read_text_chunk(FFTextReader
*tr
, AVBPrint
*buf
);
180 * Get the number of characters to increment to jump to the next line, or to
181 * the end of the string.
182 * The function handles the following line breaks schemes:
183 * LF, CRLF (MS), or standalone CR (old MacOS).
185 static av_always_inline
int ff_subtitles_next_line(const char *ptr
)
187 int n
= strcspn(ptr
, "\r\n");
199 * Read a line of text. Discards line ending characters.
200 * The function handles the following line breaks schemes:
201 * LF, CRLF (MS), or standalone CR (old MacOS).
203 * Returns the number of bytes written to buf. Always writes a terminating 0,
204 * similar as with snprintf.
206 * @note returns a negative error code if a \0 byte is found
208 ptrdiff_t ff_subtitles_read_line(FFTextReader
*tr
, char *buf
, size_t size
);
210 #endif /* AVFORMAT_SUBTITLES_H */