Phytec eGrabber-4plus, Руководство по оборудованию

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eGrabber-4plus
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PHYTEC Meßtechnik GmbH 2004 L-608e_4
The parameter dwBitsSize defines the whole size of the required
memory region of the image. This is calculated from the number of
pixels and the number of pixels per Byte: hsize
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vsize
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pixel size.
Please pay attention that dwBitsSize is the size of the complete
memory region required for the image. If even- and odd-fields are dig-
itized separately, you have to add the memory region for both fields.
More information on calculating memory requirements can be found
under the command SetImage().
Caution:
When using the Windows’95 driver, all Grabbers in the system use
the same image buffer. For this reason, two Grabbers cannot
simultaneously digitize images when the standard routine for the
driver is being used. If both Grabbers are in the digitization process,
then image data stored in the buffer will be over written.
This limitation does not exist for drivers under all the other operating
systems.
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Activate Interrupt
DWORD ActivateFieldInterrupt (WORD nDevNo,
HANDLE *hEvent);
HANDLE: Pointer to an Event
Monitoring the progress of image digitizing can also be done using the
hardware-interrupt of the framegrabber. An interrupt can be generated
at the end of every field.
The interrupt ist signaled to the software by the generation of an event.
Waiting for this event is a method to monitor the digitization progress
without polling the status flags (see DataPresent() ).
The function ActivateFieldInterrupt() sets up the interrupt
configuration of the grabber card and activates the hardware interrupt.
It creates the event and returns a pointer (handle) to this event.