/*
  * Copyright (c) 2012 Clément Bœsch
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVFORMAT_SUBTITLES_H
 #define AVFORMAT_SUBTITLES_H
 
 #include <stdint.h>
 #include "avformat.h"

 #include "libavutil/bprint.h"

 
 typedef struct {
     AVPacket *subs;         ///< array of subtitles packets
     int nb_subs;            ///< number of subtitles packets
     int allocated_size;     ///< allocated size for subs
     int current_sub_idx;    ///< current position for the read packet callback
 } FFDemuxSubtitlesQueue;
 
 /**
  * Insert a new subtitle event.
  *
  * @param event the subtitle line, may not be zero terminated
  * @param len   the length of the event (in strlen() sense, so without '\0')
  * @param merge set to 1 if the current event should be concatenated with the
  *              previous one instead of adding a new entry, 0 otherwise
  */
 AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
                                     const uint8_t *event, int len, int merge);
 
 /**
  * Set missing durations and sort subtitles by PTS, and then byte position.
  */
 void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q);
 
 /**
  * Generic read_packet() callback for subtitles demuxers using this queue
  * system.
  */
 int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt);
 
 /**

  * Update current_sub_idx to emulate a seek. Except the first parameter, it
  * matches AVInputFormat->read_seek2 prototypes.
  */
 int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index,
                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
 
 /**

  * Remove and destroy all the subtitles packets.
  */
 void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q);
 

 /**
  * SMIL helper to load next chunk ("<...>" or untagged content) in buf.
  *
  * @param c cached character, to avoid a backward seek
  */
 int ff_smil_extract_next_chunk(AVIOContext *pb, AVBPrint *buf, char *c);
 
 /**
  * SMIL helper to point on the value of an attribute in the given tag.
  *
  * @param s    SMIL tag ("<...>")
  * @param attr the attribute to look for
  */
 const char *ff_smil_get_attr_ptr(const char *s, const char *attr);
 

 /**
  * @brief Read a subtitles chunk.
  *
  * A chunk is defined by a multiline "event", ending with a second line break.

  * The trailing line breaks are trimmed. CRLF are supported.

  * Example: "foo\r\nbar\r\n\r\nnext" will print "foo\r\nbar" into buf, and pb
  * will focus on the 'n' of the "next" string.
  *
  * @param pb  I/O context
  * @param buf an initialized buf where the chunk is written
  *
  * @note buf is cleared before writing into it.
  */
 void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf);
 

 /**
  * Get the number of characters to increment to jump to the next line, or to
  * the end of the string.
  */
 static av_always_inline int ff_subtitles_next_line(const char *ptr)
 {
     int n = strcspn(ptr, "\n");
     ptr += n;
     if (*ptr == '\n')
         n++;
     return n;
 }
 

 #endif /* AVFORMAT_SUBTITLES_H */