mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
98 lines
3.8 KiB
98 lines
3.8 KiB
15 years ago
|
/*
|
||
|
|
* Utility functions for seeking for use within FFmpeg format handlers.
|
||
|
|
*
|
||
|
|
* Copyright (c) 2009 Ivan Schreter
|
||
|
|
*
|
||
|
|
* 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_SEEK_H
|
||
|
|
#define AVFORMAT_SEEK_H
|
||
|
|
|
||
|
|
#include "avformat.h"
|
||
|
|
|
||
|
|
/// Opaque structure for parser state.
|
||
|
|
typedef struct AVParserState AVParserState;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Search for sync point of all active streams.
|
||
|
|
*
|
||
|
|
* This is not supposed to be called directly by a user application,
|
||
|
|
* but by demuxers.
|
||
|
|
*
|
||
|
|
* A sync point is a point in stream, so that decoding from this point,
|
||
|
|
* output of decoders of all streams synchronizes closest to given timestamp
|
||
|
|
* ts (but taking timestamp limits into account, i.e., no sooner than ts_min
|
||
|
|
* and no later than ts_max).
|
||
|
|
*
|
||
|
|
* @param stream_index stream index for time base reference of timestamps.
|
||
|
|
* @param pos approximate position where to start searching for key frames.
|
||
|
|
* @param min_ts minimum allowed timestamp (position, if AVSEEK_FLAG_BYTE set).
|
||
|
|
* @param ts target timestamp (or position, if AVSEEK_FLAG_BYTE set in flags).
|
||
|
|
* @param max_ts maximum allowed timestamp (position, if AVSEEK_FLAG_BYTE set).
|
||
|
|
* @param flags if AVSEEK_FLAG_ANY is set, seek to any frame, otherwise only
|
||
|
|
* to a keyframe. If AVSEEK_FLAG_BYTE is set, search by
|
||
|
|
* position, not by timestamp.
|
||
|
|
* @return < 0 if no such sync point could be found, otherwise stream position
|
||
|
|
* (stream is repositioned to this position).
|
||
|
|
*/
|
||
|
|
int64_t ff_gen_syncpoint_search(AVFormatContext *s,
|
||
|
|
int stream_index,
|
||
|
|
int64_t pos,
|
||
|
|
int64_t min_ts,
|
||
|
|
int64_t ts,
|
||
|
|
int64_t max_ts,
|
||
|
|
int flags);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Store current parser state and file position.
|
||
|
|
*
|
||
|
|
* This function can be used by demuxers before destructive seeking algorithm
|
||
|
|
* to store parser state. After the seek, depending on outcome, original state
|
||
|
|
* can be restored or new state kept and original state freed.
|
||
|
|
*
|
||
|
|
* @note As a side effect, original parser state is reset, since structures
|
||
|
|
* are relinked to stored state instead of being deeply-copied (for
|
||
|
|
* performance reasons and to keep code simple).
|
||
|
|
*
|
||
|
|
* @param s context from which to save state.
|
||
|
|
* @return parser state object or NULL if memory could not be allocated.
|
||
|
|
*/
|
||
|
|
AVParserState *ff_store_parser_state(AVFormatContext *s);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Restore previously saved parser state and file position.
|
||
|
|
*
|
||
|
|
* Saved state will be invalidated and freed by this call, since internal
|
||
|
|
* structures will be relinked back to stored state instead of being
|
||
|
|
* deeply-copied.
|
||
|
|
*
|
||
|
|
* @param s context to which to restore state (same as used for storing state).
|
||
|
|
* @param state state to restore.
|
||
|
|
*/
|
||
|
|
void ff_restore_parser_state(AVFormatContext *s, AVParserState *state);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Free previously saved parser state.
|
||
|
|
*
|
||
|
|
* @param s context to which the state belongs (same as used for storing state).
|
||
|
|
* @param state state to free.
|
||
|
|
*/
|
||
|
|
void ff_free_parser_state(AVFormatContext *s, AVParserState *state);
|
||
|
|
|
||
|
|
#endif /* AVFORMAT_SEEK_H */
|