Re: PCDig and JAI CV-L103 colour camera

["M.Stein" <matthias@gom.com>]

Hi Will!

Sorry, I'm a little bit late in answering, but I don't have seen your
mail (too much mailing lists, I'm reading).

On Wed, 26 Apr 2000, Will Lockhart wrote:

> M.Stein writes:
>  > I'm not really sure about some problems with the input LUT's. The pcdig
>  > has 2 16x16bit LUT's. Till now I only use the lower one, because we don't
>  > have cameras with more than 16bit.
>  > Also the PIXEL_SIZE=24 entry in the config file will not work. My
>  > suggestion is to set PIXEL_SIZE=16, so the lower LUT is filled in a linear
>  > manner (that is what you need). Later use the HIOC_PCD_SET_LUT1 to load a
>  > self defined mapping into the upper LUT. To do this, define a union
>  > pcd_lut_t, fill it with linearized values (0->0 .... 65535->65535), and
>  > call the ioctl with the union pointer as argument. There are also some
>  > PCD_GET_LUT0|1 calls to verify the loaded mappings.
>  > 
>  > ...But not really much of this calls are tested...
>  > 
>  > The bytes should lay in the memory like
>  > 
>  > 	RGBRGBRGBRGBRGBRGB
>  > 
>  > am I right?
> 
> OK. Progress - I tried programming both LUTs to be linear, and I now
> have all three channels, and it looks like they are indeed arranged as 
> RGBRGB.
>

Very good!
 
> My next problem is one regarding doing triggered snap acquisitions
> (which I believe is essential if I want to capture more than 4MB of
> data at a time).
> 
> I did some investigation a few weeks ago and came to the conclusion
> that:
> 
> Doing a snap using a trigger only works if you have previously done a
> grab using a trigger (this is all with EXSYNC free running). You can
> test this with test_itifg. First do a config_itifg, then try
> test_itifg -t -a (snap mode, trigger) - I don't get any images. Then
> run test_itifg -t (grab mode, trigger) - I get images (at least I do
> when the images are <= 4MB). Now I run test_itifg -t -a and *now* I
> get images. So it seems to me that somehow setting the driver into
> grab mode changes some internal state which was preventing snap mode
> from working.
>

Yes, I seems, that many things at the PCDig do not work correctly, if you
are not in grabbing mode (e.g. the interrupts and writing access to 
the on-board memory). This is quite different to the IC-PCI behavior and 
that's why I enable in 0.7.0 the grab mode already in open.
For you it could be possible to start grabbing right before enabling the
trigger mode: take the CR_GRAB call from line 747 (itifgIoctl.c) and copy
it to the beginning of CR_SET_TRIGGER (line 1036).
It sounds like a fake, but at some other locations (line 830 - problems
with the on-board write access) it works and for your later triggered snap
it is not important weather the former aquisition mode was FREEZE or GRAB.

> Now, because grab mode was working for me, I though I could just use
> that for triggered acquisition, but now I realise I have to use snap
> mode.
> 
> Will
> 

						matthias