[sane-devel] Is there a buffer setting for xsane?

[Oliver Rauch]

A backend has to be able to handle all possible buffer sizes
for then sane_read command. the command "scanimage -T"
does test the behaviour of a backend with different buffer sizes.

xsane uses a sane_read with a buffer size of 64kB.

Best regards
Oliver


Am Donnerstag, 18. Januar 2007 00:57 schrieb Thomas H. George:
> Xsane color scans from my Epson Perfection 2400 scanner with a usb
> connection fail after one or two scans.  The scanner suddenly stalls in
> mid-scan.  The backend maintainer advised:
>
> "
> It's very unlikely that a change in the backend caused that problem. The
> scanner would probably not even start if something got broken. The EPSON
> ESC/I protocol (which is used by your scanner) does not allow to control
> the scan head in such a way, it either scans the complete selected area,
> or it does not scan at all.
>
> One way to find out if something in the software changed is to go back
> to an older version of the Sane system.
> You could also try to get a log file by setting the SANE_DEBUG_EPSON
> environment variable to 255.
>
> There is however one other possibility: If the USB system stalls, the
> scanner can not get rid of it's data, and it can therefore not collect
> any more data, and it may look like the scanner stalls. Does this happen
> regardless of the scan resolution?
> "
>
> The problem does seem to be that the usb system stalls, perhaps because
> a buffer is full?  scanimage has an option -B to change a buffer size.
> Is there a buffer setting for xsane?  If so, how is it set?
>
> Tom