video timing
video timing is tested with a simple duration of 4s and a repeatCount of 3.
The media length is 10s. This means the last part of the media
is never played, only the initial 4s are repeated.
Because only the timing is tested, it is not important, whether
the used format animated GIF is interpreted or not; whether there is
some video content visible or not. This is tested bottom right with
a switch. Either in this area the animated GIF is displayed or
there is noted 'switch: no GIF' in black on white.
If 'switch: GIF ok' in black on red-magenta, the GIF is not displayed
and the switch for requiredFormats is wrong.
The timing is derived using the begin and end of the video as syncbases
for the begin and end for a rotation of a blue square.
This rotation reference is compared with a
red rotating square behind with the same begin and end using
simple offset values. If something red gets visible, an error is
occured.
switch: GIF ok
switch: no GIF