FixedFrameQuantiser Class Reference

#include "lib/time/quantiser.hpp"

Description

Simple stand-alone Quantiser implementation based on a constant sized gird.

This is a self-contained quantiser implementation without any implicit referral to the Lumiera session. As such it is suited for simplified unit testing.

Warning

real Stage and Steam-Layer code should always fetch a quantiser from the Session, referring to a pre defined TimeGrid. Basically, the overall purpose of the time-quantisation framework is to enforce such a link to a distinct time scale and quantisation, so to prevent "wild and uncoordinated" rounding attempts.

Definition at line 144 of file quantiser.hpp.

Public Member Functions
	FixedFrameQuantiser (FrameRate const &frames_per_second, TimeValue referencePoint=TimeValue(0))
	Create a quantiser based on a fixed constant spaced grid, rooted at the reference point as origin of the scale. More...
	FixedFrameQuantiser (Duration const &frame_duration, TimeValue referencePoint=TimeValue(0))
TimeValue	gridLocal (TimeValue const &) const
	transform into the local time scale grid aligned. More...
FrameCnt	gridPoint (TimeValue const &) const
	grid quantisation (alignment). More...
TimeValue	timeOf (FrameCnt gridPoint) const
	calculate time value of a grid interval (frame) start point More...
TimeValue	timeOf (FSecs, int=0) const
	calculate time coordinates of a time spec relative to this quantised time scale More...
Public Member Functions inherited from Quantiser
TimeValue	materialise (TimeValue const &raw) const
	convenience shortcut: materialise a raw time value based on this grid or time axis, but returning a raw time value. More...
template<class FMT >
bool	supports () const
Public Member Functions inherited from Grid
virtual	~Grid ()
	this is an Interface

Private Attributes
Time	origin_
Duration	raster_

Additional Inherited Members
Static Public Member Functions inherited from Quantiser
static PQuant	retrieve (Symbol gridID)
	Access an existing grid definition or quantiser, known by the given symbolic ID. More...
Protected Attributes inherited from Quantiser
format::Supported	supportedFormats_

Constructor & Destructor Documentation

FixedFrameQuantiser()

FixedFrameQuantiser	(	FrameRate const &	frames_per_second,
		TimeValue	referencePoint = TimeValue(0)
	)

Create a quantiser based on a fixed constant spaced grid, rooted at the reference point as origin of the scale.

Quantisation then means to determine the grid interval containing a given raw time value. Here, the grid interval number zero starts at the origin; each interval includes its lower bound and excludes its upper bound.

Definition at line 84 of file quantiser.cpp.

Member Function Documentation

gridPoint()

FrameCnt gridPoint ( TimeValue const &  rawTime ) const

virtual

grid quantisation (alignment).

Determine the next lower grid interval start point, using a simple constant spaced time grid defined by origin and framerate stored within this quantiser.

Warning

returned frame count might exceed the valid range when converting back into a TimeValue.

See also

lumiera_quantise_frames

Implements Quantiser.

Definition at line 126 of file quantiser.cpp.

References lumiera_quantise_frames().

Referenced by Quantiser::materialise().

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gridLocal()

TimeValue gridLocal ( TimeValue const &  rawTime ) const

virtual

transform into the local time scale grid aligned.

The actual calculation first determines the number of the grid interval containing the given rawTime, then followed by multiplying this interval number with the grid spacing.

Returns

time of the start point of the grid interval containing the rawTime, relative to the origin of the time scale used by this quantiser.

Warning

returned time values are limited by the valid range of lumiera::Time

See also

lumiera_quantise_time

Implements Quantiser.

Definition at line 145 of file quantiser.cpp.

References lumiera_quantise_time().

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timeOf() [1/2]

TimeValue timeOf ( FrameCnt  gridPoint ) const

virtual

calculate time value of a grid interval (frame) start point

Returns

time point measured in Lumiera internal time

Warning

returned time values are limited by the valid range of lumiera::Time

Implements Quantiser.

Definition at line 157 of file quantiser.cpp.

References lumiera_time_of_gridpoint().

Referenced by Quantiser::materialise().

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timeOf() [2/2]

TimeValue timeOf ( FSecs  gridTime, int  gridOffset = 0  ) const

virtual

calculate time coordinates of a time spec relative to this quantised time scale

Parameters

gridTime	seconds relative to the origin of this scale
gridOffset	additional offset in grid intervals (frames)

Returns

time point measured in Lumiera internal time

Warning

returned time values are limited by the valid range of lumiera::Time

Implements Quantiser.

Definition at line 171 of file quantiser.cpp.

References LUMIERA_ERROR_DEFINE.

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The documentation for this class was generated from the following files:

• quantiser.hpp
• quantiser.cpp