[sane-devel] More ECP woes? Or just a strange format?

John Coppens john at jcoppens.com
Tue Sep 23 01:52:30 BST 2003

On Mon, 22 Sep 2003 15:56:22 +1000
Matthew Duggan <stauff at guarana.org> wrote:

> I'd recommend using libieee1284 for this sort of thing.  It nicely
> encapsulates all the ECP/EPP/BIDIR/etc modes in a mostly-cross-platform
> way.  It is my long-term ambition to add sanei_parport calls which use
> libieee1284, then finally get the parport backends to be portable and 
> not all do their own crazy thing.

Hello Matthew.

Thanks to the ieee-lib I'm getting somewhere. I miraculously coaxed the
camera in sending an image to me. I'm quite in the dark how things work,
but I tried to mimic the windows behaviour.

But when I download the image I get strange values inserted at strange
intervals, which disrupt the image, of course. Apparently the image is
sent by default as YUV9, sending 4 lines of Y, then two half-lines as U
and V.

I get an extra byte after 0x2f80, then after 0x5f00, etc. The extra bytes
seem to be random values, unrelated to the camera at first sight.

I am worried about the other modules loaded. Is one of the others
interrogating the ECP port regularly? (lp? ppdev?) How can I avoid this -
it seems lp is loaded automatically when opening the ECP port.

I'd appreciate suggestions...


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