Instruction manual

channel (calling el_AssignBuffer with channel ID 0).
There is one exception if the memory acquisition format is set to el_DUAL. In this case the data is
written to different lines within the buffer (if the camera adaptation supports this). For a camera like
the JAI CV-M10 which provides even and odd field at the same time at two different outputs this can
be used to transfer the even lines over one DMA-channel and the odd lines over another channel.
B.1.4.
What methods to allocate buffers do exist?
The software can handle two different memory management methods. The first on is to apply a 0
pointer to the MemStart parameter of el_InitHW, el_NewMemBuffer, el_NewMemBufferEx or
el_CreateMemBuffer. These functions return all a pointer to pointer list. The elements of the list then
point to the memory buffers.
Another method is to build a list like the one return by the functions mentioned above with self
allocated memory. The pointer list must be one element longer than the number of frames in the
sequence ( a single buffer can be seen as a sequence with the length 1) because the last element
of the list has to be 0. For some software versions the addresses of the buffers have to lie on a
page boundary (modulo 4096 = 0). Please refer to the software documentation for details.
If the self generated list is used as the MemStart parameter of the functions mentioned above, the
supplied memory areas are locked at their current physical position in the memory. This means that
they are protected against being transferred into the swap file. The list returned by the function is
identical to the supplied list.
B.1.5.
What is the Dual Mode?
Special cameras deliver the even and the odd image on separate video channels simultaneously.
The grabber can combine these channel to one image with twice of the normal frame rate.
ppVidPtr = el_InitHW(.......,&nBufNo);
:
el_SetAcqMemFormat (nBoardId, EL_DUAL);
el_SetVideoInPort(nBoardId, EL_CAMPARALLEL);
ppVidPtr = el_AssignBuffer(nBoardId,1,nBufNo,1.0, 1.0,0,0);
:
set acquisition format of the buffer assigned to channel 0 to EL_DUAL.
connect video data stream of input channel 1 to DMA channel 1.
assign buffer also to channel 1. Data coming through this channel is sorted between the lines
of channel 0.
B.1.6.
What is the Stereo Mode ?
In the stereo mode the images of two cameras are stored in two different buffers. The two cameras
have to be synchronized externally. The jumpers which have to be set are described in the
Appendix B. FAQs
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