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.
53 * The purpose of FFTextReader is to transparently convert read data to UTF-8
54 * if the stream had a UTF-16 BOM.
56 * @param r object which will be initialized
57 * @param pb stream to read from (referenced as long as FFTextReader is in use)
59 void ff_text_init_avio(FFTextReader *r, AVIOContext *pb);
62 * Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer.
64 * @param r object which will be initialized
65 * @param buf buffer to read from (referenced as long as FFTextReader is in use)
66 * @param size size of buf
68 void ff_text_init_buf(FFTextReader *r, void *buf, size_t size);
71 * Return the byte position of the next byte returned by ff_text_r8(). For
72 * UTF-16 source streams, this will return the original position, but it will
73 * be incorrect if a codepoint was only partially read with ff_text_r8().
75 int64_t ff_text_pos(FFTextReader *r);
78 * Return the next byte. The return value is always 0 - 255. Returns 0 on EOF.
79 * If the source stream is UTF-16, this reads from the stream converted to
80 * UTF-8. On invalid UTF-16, 0 is returned.
82 int ff_text_r8(FFTextReader *r);
85 * Return non-zero if EOF was reached.
87 int ff_text_eof(FFTextReader *r);
90 * Like ff_text_r8(), but don't remove the byte from the buffer.
92 int ff_text_peek_r8(FFTextReader *r);
95 * Read the given number of bytes (in UTF-8). On error or EOF, \0 bytes are
98 void ff_text_read(FFTextReader *r, char *buf, size_t size);
101 AVPacket *subs; ///< array of subtitles packets
102 int nb_subs; ///< number of subtitles packets
103 int allocated_size; ///< allocated size for subs
104 int current_sub_idx; ///< current position for the read packet callback
105 enum sub_sort sort; ///< sort method to use when finalizing subtitles
106 } FFDemuxSubtitlesQueue;
109 * Insert a new subtitle event.
111 * @param event the subtitle line, may not be zero terminated
112 * @param len the length of the event (in strlen() sense, so without '\0')
113 * @param merge set to 1 if the current event should be concatenated with the
114 * previous one instead of adding a new entry, 0 otherwise
116 AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
117 const uint8_t *event, int len, int merge);
120 * Set missing durations and sort subtitles by PTS, and then byte position.
122 void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q);
125 * Generic read_packet() callback for subtitles demuxers using this queue
128 int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt);
131 * Update current_sub_idx to emulate a seek. Except the first parameter, it
132 * matches AVInputFormat->read_seek2 prototypes.
134 int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index,
135 int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
138 * Remove and destroy all the subtitles packets.
140 void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q);
143 * SMIL helper to load next chunk ("<...>" or untagged content) in buf.
145 * @param c cached character, to avoid a backward seek
147 int ff_smil_extract_next_text_chunk(FFTextReader *tr, AVBPrint *buf, char *c);
150 * SMIL helper to point on the value of an attribute in the given tag.
152 * @param s SMIL tag ("<...>")
153 * @param attr the attribute to look for
155 const char *ff_smil_get_attr_ptr(const char *s, const char *attr);
158 * @brief Same as ff_subtitles_read_text_chunk(), but read from an AVIOContext.
160 void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf);
163 * @brief Read a subtitles chunk from FFTextReader.
165 * A chunk is defined by a multiline "event", ending with a second line break.
166 * The trailing line breaks are trimmed. CRLF are supported.
167 * Example: "foo\r\nbar\r\n\r\nnext" will print "foo\r\nbar" into buf, and pb
168 * will focus on the 'n' of the "next" string.
170 * @param tr I/O context
171 * @param buf an initialized buf where the chunk is written
173 * @note buf is cleared before writing into it.
175 void ff_subtitles_read_text_chunk(FFTextReader *tr, AVBPrint *buf);
178 * Get the number of characters to increment to jump to the next line, or to
179 * the end of the string.
180 * The function handles the following line breaks schemes:
181 * LF, CRLF (MS), or standalone CR (old MacOS).
183 static av_always_inline int ff_subtitles_next_line(const char *ptr)
185 int n = strcspn(ptr, "\r\n");
197 * Read a line of text. Discards line ending characters.
198 * The function handles the following line breaks schemes:
199 * LF, CRLF (MS), or standalone CR (old MacOS).
201 * Returns the number of bytes written to buf. Always writes a terminating 0,
202 * similar as with snprintf.
204 * @note returns a negative error code if a \0 byte is found
206 ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size);
208 #endif /* AVFORMAT_SUBTITLES_H */