This reveal filter controls a transition effect that specifies the kind of wipe to use between the hiding and showing of a filtered element.
The duration name=value pair is specified in the same way as for the blendTrans() filter. It specifies a floating point value in seconds which controls how quickly the effect should take place.
The transition-shape name=value pair specifies the kind of wipe effect to use. It is an integer value which defines the following wipe patterns:
|13||Split vertical in|
|14||Split vertical out|
|15||Split horizontal in|
|16||Split horizontal out|
|17||Strips left down|
|18||Strips left up|
|19||Strips right down|
|20||Strips right up|
|21||Random bars horizontal|
|22||Random bars vertical|
These are loosely modelled on some of the standard SMPTE wipes and dissolves although the full complement is not available.
This is deprecated in favor of using named filters that provide the visual transition effect.
Filters are defined in style sheets as if they were a function call with its arguments expressed as name=value pairs. This is not the typical way to define arguments so you should be aware of this anomaly when working with filters.