213 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			213 lines
		
	
	
		
			6.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2012 Clément Bœsch
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #ifndef AVFORMAT_SUBTITLES_H
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| #define AVFORMAT_SUBTITLES_H
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| 
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| #include <stdint.h>
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| #include <stddef.h>
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| #include "avformat.h"
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| #include "libavutil/bprint.h"
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| 
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| enum sub_sort {
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|     SUB_SORT_TS_POS = 0,    ///< sort by timestamps, then position
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|     SUB_SORT_POS_TS,        ///< sort by position, then timestamps
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| };
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| 
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| enum ff_utf_type {
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|     FF_UTF_8,       // or other 8 bit encodings
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|     FF_UTF16LE,
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|     FF_UTF16BE,
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| };
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| 
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| typedef struct {
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|     int type;
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|     AVIOContext *pb;
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|     unsigned char buf[8];
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|     int buf_pos, buf_len;
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|     AVIOContext buf_pb;
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| } FFTextReader;
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| 
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| /**
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|  * Initialize the FFTextReader from the given AVIOContext. This function will
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|  * read some bytes from pb, and test for UTF-8 or UTF-16 BOMs. Further accesses
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|  * to FFTextReader will read more data from pb.
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|  * If s is not NULL, the user will be warned if a UTF-16 conversion takes place.
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|  *
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|  * The purpose of FFTextReader is to transparently convert read data to UTF-8
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|  * if the stream had a UTF-16 BOM.
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|  *
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|  * @param s Pointer to provide av_log context
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|  * @param r object which will be initialized
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|  * @param pb stream to read from (referenced as long as FFTextReader is in use)
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|  */
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| void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb);
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| 
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| /**
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|  * Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer.
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|  *
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|  * @param r object which will be initialized
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|  * @param buf buffer to read from (referenced as long as FFTextReader is in use)
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|  * @param size size of buf
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|  */
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| void ff_text_init_buf(FFTextReader *r, void *buf, size_t size);
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| 
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| /**
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|  * Return the byte position of the next byte returned by ff_text_r8(). For
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|  * UTF-16 source streams, this will return the original position, but it will
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|  * be incorrect if a codepoint was only partially read with ff_text_r8().
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|  */
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| int64_t ff_text_pos(FFTextReader *r);
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| 
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| /**
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|  * Return the next byte. The return value is always 0 - 255. Returns 0 on EOF.
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|  * If the source stream is UTF-16, this reads from the stream converted to
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|  * UTF-8. On invalid UTF-16, 0 is returned.
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|  */
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| int ff_text_r8(FFTextReader *r);
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| 
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| /**
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|  * Return non-zero if EOF was reached.
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|  */
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| int ff_text_eof(FFTextReader *r);
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| 
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| /**
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|  * Like ff_text_r8(), but don't remove the byte from the buffer.
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|  */
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| int ff_text_peek_r8(FFTextReader *r);
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| 
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| /**
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|  * Read the given number of bytes (in UTF-8). On error or EOF, \0 bytes are
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|  * written.
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|  */
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| void ff_text_read(FFTextReader *r, char *buf, size_t size);
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| 
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| typedef struct {
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|     AVPacket *subs;         ///< array of subtitles packets
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|     int nb_subs;            ///< number of subtitles packets
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|     int allocated_size;     ///< allocated size for subs
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|     int current_sub_idx;    ///< current position for the read packet callback
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|     enum sub_sort sort;     ///< sort method to use when finalizing subtitles
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|     int keep_duplicates;    ///< set to 1 to keep duplicated subtitle events
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| } FFDemuxSubtitlesQueue;
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| 
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| /**
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|  * Insert a new subtitle event.
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|  *
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|  * @param event the subtitle line, may not be zero terminated
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|  * @param len   the length of the event (in strlen() sense, so without '\0')
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|  * @param merge set to 1 if the current event should be concatenated with the
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|  *              previous one instead of adding a new entry, 0 otherwise
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|  */
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| AVPacket *ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q,
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|                                     const uint8_t *event, size_t len, int merge);
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| 
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| /**
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|  * Set missing durations, sort subtitles by PTS (and then byte position), and
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|  * drop duplicated events.
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|  */
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| void ff_subtitles_queue_finalize(void *log_ctx, FFDemuxSubtitlesQueue *q);
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| 
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| /**
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|  * Generic read_packet() callback for subtitles demuxers using this queue
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|  * system.
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|  */
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| int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt);
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| 
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| /**
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|  * Update current_sub_idx to emulate a seek. Except the first parameter, it
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|  * matches AVInputFormat->read_seek2 prototypes.
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|  */
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| int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index,
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|                             int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
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| 
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| /**
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|  * Remove and destroy all the subtitles packets.
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|  */
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| void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q);
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| 
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| /**
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|  * SMIL helper to load next chunk ("<...>" or untagged content) in buf.
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|  *
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|  * @param c cached character, to avoid a backward seek
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|  */
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| int ff_smil_extract_next_text_chunk(FFTextReader *tr, AVBPrint *buf, char *c);
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| 
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| /**
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|  * SMIL helper to point on the value of an attribute in the given tag.
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|  *
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|  * @param s    SMIL tag ("<...>")
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|  * @param attr the attribute to look for
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|  */
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| const char *ff_smil_get_attr_ptr(const char *s, const char *attr);
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| 
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| /**
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|  * @brief Same as ff_subtitles_read_text_chunk(), but read from an AVIOContext.
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|  */
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| void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf);
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| 
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| /**
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|  * @brief Read a subtitles chunk from FFTextReader.
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|  *
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|  * A chunk is defined by a multiline "event", ending with a second line break.
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|  * The trailing line breaks are trimmed. CRLF are supported.
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|  * Example: "foo\r\nbar\r\n\r\nnext" will print "foo\r\nbar" into buf, and pb
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|  * will focus on the 'n' of the "next" string.
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|  *
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|  * @param tr  I/O context
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|  * @param buf an initialized buf where the chunk is written
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|  *
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|  * @note buf is cleared before writing into it.
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|  */
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| void ff_subtitles_read_text_chunk(FFTextReader *tr, AVBPrint *buf);
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| 
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| /**
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|  * Get the number of characters to increment to jump to the next line, or to
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|  * the end of the string.
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|  * The function handles the following line breaks schemes:
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|  * LF, CRLF (MS), or standalone CR (old MacOS).
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|  */
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| static av_always_inline int ff_subtitles_next_line(const char *ptr)
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| {
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|     int n = strcspn(ptr, "\r\n");
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|     ptr += n;
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|     while (*ptr == '\r') {
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|         ptr++;
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|         n++;
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|     }
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|     if (*ptr == '\n')
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|         n++;
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|     return n;
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| }
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| 
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| /**
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|  * Read a line of text. Discards line ending characters.
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|  * The function handles the following line breaks schemes:
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|  * LF, CRLF (MS), or standalone CR (old MacOS).
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|  *
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|  * Returns the number of bytes written to buf. Always writes a terminating 0,
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|  * similar as with snprintf.
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|  *
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|  * @note returns a negative error code if a \0 byte is found
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|  */
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| ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size);
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| 
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| #endif /* AVFORMAT_SUBTITLES_H */
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