Phytec pciGrabber4x4, Руководство по оборудованию

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pciGrabber-4x4
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PHYTEC Messtechnik GmbH 2008 L-720e_0
When does the first digitization take place?
The driver handles whole frames. Always even/odd image
combinations are evaluated. The timing will then depend on the
desired field and the start up time currently applied field at the video
input. We have to distinguish the following cases:
(1) An even-field is required to be digitized
a) At the input an even-field is applied:
Since the image just in process can not be evaluated anymore
(the beginning is missing), the rest of the even field and the
next odd field will pass and then digitization will start. So the
next complete even field will be digitized.
The delay from the start instruction to digitizing will be
< 40 msec.
b) At the input an odd field is applied:
The even field following the odd field will be digitized.
Maximum delay time: 20 msec.
(2) An odd-field is required to be digitized
a) At the input an even field is applied
Since the driver evaluates even fields first, the rest of the
incomplete even field and the following odd field will pass,
until the Grabber will synchronize with the next even field.
Now the starting odd field will be digitized. The maximum
delay will be < 60 msec.
b) At the input an odd field is applied
First the incomplete odd field will pass, and then the Grabber
will be synchronized with the following even field, and will
start the subsequent odd field. The maximum delay will be :
< 40 msec.