/* * 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 <stddef.h> #include "avformat.h" #include "libavutil/bprint.h" enum sub_sort { SUB_SORT_TS_POS = 0, ///< sort by timestamps, then position SUB_SORT_POS_TS, ///< sort by position, then timestamps }; enum ff_utf_type { FF_UTF_8, // or other 8 bit encodings FF_UTF16LE, FF_UTF16BE, }; typedef struct { int type; AVIOContext *pb; unsigned char buf[8]; int buf_pos, buf_len; AVIOContext buf_pb; } FFTextReader; /** * Initialize the FFTextReader from the given AVIOContext. This function will * read some bytes from pb, and test for UTF-8 or UTF-16 BOMs. Further accesses * to FFTextReader will read more data from pb. * If s is not NULL, the user will be warned if a UTF-16 conversion takes place. * * The purpose of FFTextReader is to transparently convert read data to UTF-8 * if the stream had a UTF-16 BOM. * * @param s Pointer to provide av_log context * @param r object which will be initialized * @param pb stream to read from (referenced as long as FFTextReader is in use) */ void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb); /** * Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer. * * @param r object which will be initialized * @param buf buffer to read from (referenced as long as FFTextReader is in use) * @param size size of buf */ void ff_text_init_buf(FFTextReader *r, void *buf, size_t size); /** * Return the byte position of the next byte returned by ff_text_r8(). For * UTF-16 source streams, this will return the original position, but it will * be incorrect if a codepoint was only partially read with ff_text_r8(). */ int64_t ff_text_pos(FFTextReader *r); /** * Return the next byte. The return value is always 0 - 255. Returns 0 on EOF. * If the source stream is UTF-16, this reads from the stream converted to * UTF-8. On invalid UTF-16, 0 is returned. */ int ff_text_r8(FFTextReader *r); /** * Return non-zero if EOF was reached. */ int ff_text_eof(FFTextReader *r); /** * Like ff_text_r8(), but don't remove the byte from the buffer. */ int ff_text_peek_r8(FFTextReader *r); /** * Read the given number of bytes (in UTF-8). On error or EOF, \0 bytes are * written. */ void ff_text_read(FFTextReader *r, char *buf, size_t size); 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 enum sub_sort sort; ///< sort method to use when finalizing subtitles } 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, size_t 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_text_chunk(FFTextReader *tr, 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 Same as ff_subtitles_read_text_chunk(), but read from an AVIOContext. */ void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf); /** * @brief Read a subtitles chunk from FFTextReader. * * 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 tr 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_text_chunk(FFTextReader *tr, AVBPrint *buf); /** * Get the number of characters to increment to jump to the next line, or to * the end of the string. * The function handles the following line breaks schemes: * LF, CRLF (MS), or standalone CR (old MacOS). */ static av_always_inline int ff_subtitles_next_line(const char *ptr) { int n = strcspn(ptr, "\r\n"); ptr += n; if (*ptr == '\r') { ptr++; n++; } if (*ptr == '\n') n++; return n; } /** * Read a line of text. Discards line ending characters. * The function handles the following line breaks schemes: * LF, CRLF (MS), or standalone CR (old MacOS). * * Returns the number of bytes written to buf. Always writes a terminating 0, * similar as with snprintf. * * @note returns a negative error code if a \0 byte is found */ ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size); #endif /* AVFORMAT_SUBTITLES_H */