#include "lib/time/timecode.hpp"

Description

Classical Timecode value reminiscent to SMPTE format.

After quantisation, the resulting (materialised) time value is decimated into a hours, a minutes, a seconds part and the remainder is cast into a frame number relative to the seconds. Consequently, a SmpteTC representation is always linked implicitly to a specific framerate.

range extensions

Historically, SMPTE timecode format was focused mainly on how to encode a unique timestamp in a way allowing to 'piggyback' these timestamps into an existing (analogue) media data format. As a side effect, quite tight limits had to be imposed on the possible component values in such a fixed-length format. This whole concern is completely beyond the scope of a typical computer based video implementation; thus we can consider ways to extend the value range to be represented in this SMPTE-like timecode format:

we can allow time values below the zero point
we can allow time values beyond 24 hours. Several different schemes how to do this extensions could be devised (and in addition, we could also wrap around the hours field, jumping from 23:59:59:## to 0:0:0:0). Currently, we implement an extension, where the timecode representation is symmetrical to the zero point and the hours field is just extended beyond 23 hours. To give an example: 0:0:0:0 minus 1 frame yields -0:0:0:1

Todo:: the range extension scheme could be a configurable strategy

Definition at line 144 of file timecode.hpp.

Public Types
using	Format = format::Smpte

Public Attributes
HourDigit	hours

SexaDigit	mins

SexaDigit	secs

SexaDigit	frames

Signum	sgn

Public Member Functions
	SmpteTC (QuTime const &quantisedTime)

	SmpteTC (SmpteTC const &)

SmpteTC &	operator= (SmpteTC const &)

uint	getFps () const

void	clear ()

void	rebuild ()

void	invertOrientation ()
	flip the orientation of min, sec, and frames.

SmpteTC &	operator++ ()

SmpteTC &	operator-- ()

Public Member Functions inherited from TCode
virtual	~TCode ()

	operator string () const

string	describe () const

Time	getTime () const

Private Member Functions
virtual string	show () const

virtual Literal	tcID () const

virtual TimeValue	value () const

Private Attributes
uint	effectiveFramerate_

Additional Inherited Members
Protected Member Functions inherited from TCode
	TCode (PQuant const &quant)

Protected Attributes inherited from TCode
PQuant	quantiser_

Constructor & Destructor Documentation

◆ SmpteTC() [1/2]

SmpteTC ( QuTime const & quantisedTime )

Definition at line 303 of file timecode.cpp.

References QuTime::castInto().

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◆ SmpteTC() [2/2]

SmpteTC ( SmpteTC const & o )

Definition at line 312 of file timecode.cpp.

References SmpteTC::frames, SmpteTC::hours, SmpteTC::mins, SmpteTC::secs, and SmpteTC::sgn.

Member Typedef Documentation

◆ Format

using Format = format::Smpte

Definition at line 156 of file timecode.hpp.

Member Function Documentation

◆ show()

string show ( ) const

privatevirtual

Implements TCode.

Definition at line 416 of file timecode.cpp.

References SmpteTC::frames, SmpteTC::hours, SmpteTC::mins, SmpteTC::secs, SmpteTC::sgn, and Digxel< NUM, FMT >::show().

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◆ tcID()

virtual Literal tcID ( ) const

inlineprivatevirtual

Implements TCode.

Definition at line 151 of file timecode.hpp.

◆ value()

virtual TimeValue value ( ) const

inlineprivatevirtual

Implements TCode.

Definition at line 152 of file timecode.hpp.

References Smpte::evaluate(), and TCode::quantiser_.

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◆ operator=()

SmpteTC & operator= ( SmpteTC const & o )

Definition at line 326 of file timecode.cpp.

References SmpteTC::effectiveFramerate_, SmpteTC::frames, SmpteTC::hours, SmpteTC::mins, SmpteTC::secs, and SmpteTC::sgn.

◆ getFps()

uint getFps ( ) const

Definition at line 409 of file timecode.cpp.

References SmpteTC::effectiveFramerate_.

Referenced by Smpte::evaluate(), SmpteTC::invertOrientation(), and lib::time::anonymous_namespace{timecode.cpp}::wrapFrames().

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◆ clear()

void clear ( )

Definition at line 358 of file timecode.cpp.

References SmpteTC::frames, SmpteTC::hours, SmpteTC::mins, SmpteTC::secs, Digxel< NUM, FMT >::setValueRaw(), and SmpteTC::sgn.

Referenced by Smpte::rebuild().

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◆ rebuild()

void rebuild ( )

Definition at line 369 of file timecode.cpp.

References Smpte::evaluate(), TCode::quantiser_, and Smpte::rebuild().

Referenced by TimeFormats_test::checkSmpte().

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◆ invertOrientation()

void invertOrientation ( )

flip the orientation of min, sec, and frames.

Besides changing the sign, this will flip the meaning of the component fields, which by definition are always oriented towards zero.

Normalised value fields are defined positive, with automatic overflow to next higher field. This might cause the hours to become negative. When invoked in this case, the meaning changes from -h + (m+s+f) to -(h+m+s+f)

Definition at line 388 of file timecode.cpp.

References SmpteTC::frames, SmpteTC::getFps(), SmpteTC::hours, SmpteTC::mins, SmpteTC::secs, Digxel< NUM, FMT >::setValueRaw(), and SmpteTC::sgn.

Referenced by Smpte::applyRangeLimitStrategy(), and TimeFormats_test::checkSmpte().

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