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+/*
+ * 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"
+
+enum sub_sort {
+ SUB_SORT_TS_POS = 0, ///< sort by timestamps, then position
+ SUB_SORT_POS_TS, ///< sort by position, then timestamps
+};
+
+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, 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.
+ * 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;
+}
+
+#endif /* AVFORMAT_SUBTITLES_H */