libavutil/timecode.c File Reference

Timecode helpers. More...

#include <stdio.h>
#include "timecode.h"
#include "log.h"
#include "error.h"

Go to the source code of this file.

Functions
int	av_timecode_adjust_ntsc_framenum (int framenum)
	Adjust frame number for NTSC drop frame time code.
uint32_t	av_timecode_get_smpte_from_framenum (const AVTimecode *tc, int framenum)
	Convert frame number to SMPTE 12M binary representation.
char *	av_timecode_make_string (const AVTimecode *tc, char *buf, int framenum)
	Load timecode string in buf.
static unsigned	bcd2uint (uint8_t bcd)
char *	av_timecode_make_smpte_tc_string (char *buf, uint32_t tcsmpte, int prevent_df)
	Get the timecode string from the SMPTE timecode format.
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).
static int	check_timecode (void *log_ctx, AVTimecode *tc)
static int	fps_from_frame_rate (AVRational rate)
int	av_timecode_init (AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
	Init a timecode struct with the passed parameters.
int	av_timecode_init_from_string (AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
	Parse timecode representation (hh:mm:ss[:;.

---

Detailed Description

Timecode helpers.

See also:

https://en.wikipedia.org/wiki/SMPTE_time_code

http://www.dropframetimecode.org

Definition in file timecode.c.

---

Function Documentation

int av_timecode_adjust_ntsc_framenum

(

int

framenum

)

Adjust frame number for NTSC drop frame time code.

Parameters:

framenum

frame number to adjust

Returns:

adjusted frame number

Warning:

adjustment is only valid in NTSC 29.97

Definition at line 34 of file timecode.c.

Referenced by av_timecode_get_smpte_from_framenum(), av_timecode_make_string(), and mpeg1_encode_sequence_header().

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

Note:

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

The frame number is relative to tc->start.

Color frame (CF), binary group flags (BGF) and biphase mark polarity correction (PC) bits are set to zero.

Definition at line 43 of file timecode.c.

Referenced by dv_write_pack(), and mxf_write_system_item().

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

Definition at line 157 of file timecode.c.

Referenced by dv_write_header(), mxf_parse_structural_metadata(), mxf_write_header(), and parse_timecode_in_framenum_format().

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

Definition at line 167 of file timecode.c.

Referenced by dv_write_header(), encode_init(), init(), and mxf_write_header().

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

Definition at line 118 of file timecode.c.

Referenced by mpeg_decode_gop(), and show_stream().

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

Definition at line 106 of file timecode.c.

Referenced by dv_extract_timecode().

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.

Definition at line 72 of file timecode.c.

Referenced by draw_text(), mxf_add_timecode_metadata(), and parse_timecode_in_framenum_format().

static unsigned bcd2uint

(

uint8_t

bcd

)

[static]

Definition at line 97 of file timecode.c.

Referenced by av_timecode_make_smpte_tc_string().

static int check_timecode	(	void *	log_ctx,
		AVTimecode *	tc
	)			[static]

Definition at line 129 of file timecode.c.

Referenced by av_timecode_init(), and av_timecode_init_from_string().

static int fps_from_frame_rate

(

AVRational

rate

)

[static]

Definition at line 150 of file timecode.c.

Referenced by av_timecode_init(), and av_timecode_init_from_string().