timecode.h File Reference

Timecode helpers header. More...

#include <stdint.h>
#include "rational.h"

Go to the source code of this file.

Data Structures
struct	AVTimecode

Macros
#define	AV_TIMECODE_STR_SIZE   23

Enumerations
enum	AVTimecodeFlag { AV_TIMECODE_FLAG_DROPFRAME = 1<<0 , AV_TIMECODE_FLAG_24HOURSMAX = 1<<1 , AV_TIMECODE_FLAG_ALLOWNEGATIVE = 1<<2 }

Functions
int	av_timecode_adjust_ntsc_framenum2 (int framenum, int fps)
	Adjust frame number for NTSC drop frame time code. More...
uint32_t	av_timecode_get_smpte_from_framenum (const AVTimecode *tc, int framenum)
	Convert frame number to SMPTE 12M binary representation. More...
uint32_t	av_timecode_get_smpte (AVRational rate, int drop, int hh, int mm, int ss, int ff)
	Convert sei info to SMPTE 12M binary representation. More...
char *	av_timecode_make_string (const AVTimecode *tc, char *buf, int framenum)
	Load timecode string in buf. More...
char *	av_timecode_make_smpte_tc_string2 (char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
	Get the timecode string from the SMPTE timecode format. More...
char *	av_timecode_make_smpte_tc_string (char *buf, uint32_t tcsmpte, int prevent_df)
	Get the timecode string from the SMPTE timecode format. More...
char *	av_timecode_make_mpeg_tc_string (char *buf, uint32_t tc25bit)
	Get the timecode string from the 25-bit timecode format (MPEG GOP format). More...
int	av_timecode_init (AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
	Init a timecode struct with the passed parameters. More...
int	av_timecode_init_from_components (AVTimecode *tc, AVRational rate, int flags, int hh, int mm, int ss, int ff, void *log_ctx)
	Init a timecode struct from the passed timecode components. More...
int	av_timecode_init_from_string (AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
	Parse timecode representation (hh:mm:ss[:;. More...
int	av_timecode_check_frame_rate (AVRational rate)
	Check if the timecode feature is available for the given frame rate. More...

Detailed Description

Timecode helpers header.

Definition in file timecode.h.

Macro Definition Documentation

AV_TIMECODE_STR_SIZE

#define AV_TIMECODE_STR_SIZE   23

Definition at line 33 of file timecode.h.

Enumeration Type Documentation

AVTimecodeFlag

enum AVTimecodeFlag

Enumerator
AV_TIMECODE_FLAG_DROPFRAME	timecode is drop frame
AV_TIMECODE_FLAG_24HOURSMAX	timecode wraps after 24 hours
AV_TIMECODE_FLAG_ALLOWNEGATIVE	negative time values are allowed

Definition at line 35 of file timecode.h.

Function Documentation

av_timecode_adjust_ntsc_framenum2()

int av_timecode_adjust_ntsc_framenum2	(	int	framenum,
		int	fps
	)

Adjust frame number for NTSC drop frame time code.

Parameters

framenum	frame number to adjust
fps	frame per second, multiples of 30

Returns

adjusted frame number

Warning

adjustment is only valid for multiples of NTSC 29.97

av_timecode_get_smpte_from_framenum()

uint32_t av_timecode_get_smpte_from_framenum	(	const AVTimecode *	tc,
		int	framenum
	)

Convert frame number to SMPTE 12M binary representation.

Parameters

tc	timecode data correctly initialized
framenum	frame number

Returns

the SMPTE binary representation

See SMPTE ST 314M-2005 Sec 4.4.2.2.1 "Time code pack (TC)" the format description as follows: bits 0-5: hours, in BCD(6bits) bits 6: BGF1 bits 7: BGF2 (NTSC) or FIELD (PAL) bits 8-14: minutes, in BCD(7bits) bits 15: BGF0 (NTSC) or BGF2 (PAL) bits 16-22: seconds, in BCD(7bits) bits 23: FIELD (NTSC) or BGF0 (PAL) bits 24-29: frames, in BCD(6bits) bits 30: drop frame flag (0: non drop, 1: drop) bits 31: color frame flag (0: unsync mode, 1: sync mode)

Note

BCD numbers (6 or 7 bits): 4 or 5 lower bits for units, 2 higher bits for tens.

Frame number adjustment is automatically done in case of drop timecode, you do NOT have to call av_timecode_adjust_ntsc_framenum2().

The frame number is relative to tc->start.

Color frame (CF) and binary group flags (BGF) bits are set to zero.

av_timecode_get_smpte()

uint32_t av_timecode_get_smpte	(	AVRational	rate,
		int	drop,
		int	hh,
		int	mm,
		int	ss,
		int	ff
	)

Convert sei info to SMPTE 12M binary representation.

Parameters

rate	frame rate in rational form
drop	drop flag
hh	hour
mm	minute
ss	second
ff	frame number

Returns

the SMPTE binary representation

av_timecode_make_string()

char * av_timecode_make_string	(	const AVTimecode *	tc,
		char *	buf,
		int	framenum
	)

Load timecode string in buf.

Parameters

buf	destination buffer, must be at least AV_TIMECODE_STR_SIZE long
tc	timecode data correctly initialized
framenum	frame number

Returns

the buf parameter

Note

Timecode representation can be a negative timecode and have more than 24 hours, but will only be honored if the flags are correctly set.

The frame number is relative to tc->start.

av_timecode_make_smpte_tc_string2()

char * av_timecode_make_smpte_tc_string2	(	char *	buf,
		AVRational	rate,
		uint32_t	tcsmpte,
		int	prevent_df,
		int	skip_field
	)

Get the timecode string from the SMPTE timecode format.

In contrast to av_timecode_make_smpte_tc_string this function supports 50/60 fps timecodes by using the field bit.

Parameters

buf	destination buffer, must be at least AV_TIMECODE_STR_SIZE long
rate	frame rate of the timecode
tcsmpte	the 32-bit SMPTE timecode
prevent_df	prevent the use of a drop flag when it is known the DF bit is arbitrary
skip_field	prevent the use of a field flag when it is known the field bit is arbitrary (e.g. because it is used as PC flag)

Returns

the buf parameter

av_timecode_make_smpte_tc_string()

char * av_timecode_make_smpte_tc_string	(	char *	buf,
		uint32_t	tcsmpte,
		int	prevent_df
	)

Get the timecode string from the SMPTE timecode format.

Parameters

buf	destination buffer, must be at least AV_TIMECODE_STR_SIZE long
tcsmpte	the 32-bit SMPTE timecode
prevent_df	prevent the use of a drop flag when it is known the DF bit is arbitrary

Returns

the buf parameter

av_timecode_make_mpeg_tc_string()

char * av_timecode_make_mpeg_tc_string	(	char *	buf,
		uint32_t	tc25bit
	)

Get the timecode string from the 25-bit timecode format (MPEG GOP format).

Parameters

buf	destination buffer, must be at least AV_TIMECODE_STR_SIZE long
tc25bit	the 25-bits timecode

Returns

the buf parameter

av_timecode_init()

int av_timecode_init	(	AVTimecode *	tc,
		AVRational	rate,
		int	flags,
		int	frame_start,
		void *	log_ctx
	)

Init a timecode struct with the passed parameters.

Parameters

log_ctx	a pointer to an arbitrary struct of which the first field is a pointer to an AVClass struct (used for av_log)
tc	pointer to an allocated AVTimecode
rate	frame rate in rational form
flags	miscellaneous flags such as drop frame, +24 hours, ... (see AVTimecodeFlag)
frame_start	the first frame number

Returns

0 on success, AVERROR otherwise

av_timecode_init_from_components()

int av_timecode_init_from_components	(	AVTimecode *	tc,
		AVRational	rate,
		int	flags,
		int	hh,
		int	mm,
		int	ss,
		int	ff,
		void *	log_ctx
	)

Init a timecode struct from the passed timecode components.

Parameters

log_ctx	a pointer to an arbitrary struct of which the first field is a pointer to an AVClass struct (used for av_log)
tc	pointer to an allocated AVTimecode
rate	frame rate in rational form
flags	miscellaneous flags such as drop frame, +24 hours, ... (see AVTimecodeFlag)
hh	hours
mm	minutes
ss	seconds
ff	frames

Returns

0 on success, AVERROR otherwise

av_timecode_init_from_string()

int av_timecode_init_from_string	(	AVTimecode *	tc,
		AVRational	rate,
		const char *	str,
		void *	log_ctx
	)

Parse timecode representation (hh:mm:ss[:;.

]ff).

Parameters

log_ctx	a pointer to an arbitrary struct of which the first field is a pointer to an AVClass struct (used for av_log).
tc	pointer to an allocated AVTimecode
rate	frame rate in rational form
str	timecode string which will determine the frame start

Returns

0 on success, AVERROR otherwise

av_timecode_check_frame_rate()

int av_timecode_check_frame_rate

(

AVRational

rate

)

Check if the timecode feature is available for the given frame rate.

Returns

0 if supported, <0 otherwise