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libavutil
timecode.h
Go to the documentation of this file.
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/*
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* Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com>
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* Copyright (c) 2011-2012 Smartjog S.A.S, Clément Bœsch <clement.boesch@smartjog.com>
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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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* @file
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* Timecode helpers header
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*/
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#ifndef AVUTIL_TIMECODE_H
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#define AVUTIL_TIMECODE_H
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#include <stdint.h>
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#include "
rational.h
"
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#define AV_TIMECODE_STR_SIZE 16
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enum
AVTimecodeFlag
{
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AV_TIMECODE_FLAG_DROPFRAME
= 1<<0,
///< timecode is drop frame
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AV_TIMECODE_FLAG_24HOURSMAX
= 1<<1,
///< timecode wraps after 24 hours
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AV_TIMECODE_FLAG_ALLOWNEGATIVE
= 1<<2,
///< negative time values are allowed
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};
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typedef
struct
{
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int
start
;
///< timecode frame start (first base frame number)
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uint32_t
flags
;
///< flags such as drop frame, +24 hours support, ...
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AVRational
rate
;
///< frame rate in rational form
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unsigned
fps
;
///< frame per second; must be consistent with the rate field
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}
AVTimecode
;
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/**
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* Adjust frame number for NTSC drop frame time code.
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*
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* @param framenum frame number to adjust
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* @param fps frame per second, 30 or 60
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* @return adjusted frame number
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* @warning adjustment is only valid in NTSC 29.97 and 59.94
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*/
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int
av_timecode_adjust_ntsc_framenum2
(
int
framenum,
int
fps);
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/**
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* Convert frame number to SMPTE 12M binary representation.
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*
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* @param tc timecode data correctly initialized
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* @param framenum frame number
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* @return the SMPTE binary representation
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*
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* @note Frame number adjustment is automatically done in case of drop timecode,
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* you do NOT have to call av_timecode_adjust_ntsc_framenum2().
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* @note The frame number is relative to tc->start.
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* @note Color frame (CF), binary group flags (BGF) and biphase mark polarity
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* correction (PC) bits are set to zero.
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*/
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uint32_t
av_timecode_get_smpte_from_framenum
(
const
AVTimecode
*
tc
,
int
framenum);
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/**
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* Load timecode string in buf.
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*
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* @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
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* @param tc timecode data correctly initialized
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* @param framenum frame number
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* @return the buf parameter
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*
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* @note Timecode representation can be a negative timecode and have more than
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* 24 hours, but will only be honored if the flags are correctly set.
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* @note The frame number is relative to tc->start.
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*/
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char
*
av_timecode_make_string
(
const
AVTimecode
*
tc
,
char
*
buf
,
int
framenum);
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/**
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* Get the timecode string from the SMPTE timecode format.
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*
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* @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
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* @param tcsmpte the 32-bit SMPTE timecode
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* @param prevent_df prevent the use of a drop flag when it is known the DF bit
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* is arbitrary
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* @return the buf parameter
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*/
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char
*
av_timecode_make_smpte_tc_string
(
char
*
buf
, uint32_t tcsmpte,
int
prevent_df);
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/**
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* Get the timecode string from the 25-bit timecode format (MPEG GOP format).
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*
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* @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
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* @param tc25bit the 25-bits timecode
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* @return the buf parameter
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*/
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char
*
av_timecode_make_mpeg_tc_string
(
char
*
buf
, uint32_t tc25bit);
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/**
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* Init a timecode struct with the passed parameters.
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*
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* @param log_ctx a pointer to an arbitrary struct of which the first field
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* is a pointer to an AVClass struct (used for av_log)
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* @param tc pointer to an allocated AVTimecode
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* @param rate frame rate in rational form
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* @param flags miscellaneous flags such as drop frame, +24 hours, ...
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* (see AVTimecodeFlag)
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* @param frame_start the first frame number
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* @return 0 on success, AVERROR otherwise
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*/
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int
av_timecode_init
(
AVTimecode
*
tc
,
AVRational
rate,
int
flags
,
int
frame_start,
void
*log_ctx);
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/**
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* Parse timecode representation (hh:mm:ss[:;.]ff).
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*
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* @param log_ctx a pointer to an arbitrary struct of which the first field is a
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* pointer to an AVClass struct (used for av_log).
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* @param tc pointer to an allocated AVTimecode
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* @param rate frame rate in rational form
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* @param str timecode string which will determine the frame start
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* @return 0 on success, AVERROR otherwise
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*/
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int
av_timecode_init_from_string
(
AVTimecode
*
tc
,
AVRational
rate,
const
char
*str,
void
*log_ctx);
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/**
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* Check if the timecode feature is available for the given frame rate
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*
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* @return 0 if supported, <0 otherwise
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*/
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int
av_timecode_check_frame_rate
(
AVRational
rate);
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#endif
/* AVUTIL_TIMECODE_H */
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