[sane-devel] Pixma height constraint for ADF

[m. allan noah]

On Thu, May 13, 2010 at 8:46 AM, Zeev Lieber <zeev.lieber at gmail.com> wrote:
> I just tried the git version of SANE with my new Canon imageCLASS
> MF4350d. Everything works fine, except for one thing: I cannot scan
> legal-size documents via the ADF.
>
> Running scanimage -h showed that the "y" parameter is bound by the
> value of 297mm (A4), which is correct for flatbed, but not for the
> ADF.
>
> So I quickly hacked pixma_imageclass.c replacing the height
> constraints (1052 instead of 877 for Legal), and also
> pixma_sane_options.c to force the default back to 297mm. This did the
> trick for me, but clearly is not a good solution in general, and
> doesn't work with xsane (only command line). Also,
> pixma_sane_options.c seems to be auto-generated, but I couldn't find
> the script that generated it, so I just did my changes in the .c file
> itself.
>
> I'm not familiar with the architecture enough to suggest what a good
> solution would be. Is there a nice way to support different
> constraints for different document sources? Or maybe just disable the
> checking of height constraint for ADF altogether? If you tell me what
> it is, and it's not too complicated I could contribute a patch for
> this.

Almost certainly the adf does have some upper limit of length it will
scan. Not a physical limit, but a logical one in the firmware. If you
can figure out what that limit is (trial and error, or using the
windows software) then you should be able to code the br_y option's
limits to a longer value when using the ADF. I don't know if there is
other code to change, perhaps one of the pixma authors will discuss.

allan
-- 
"The truth is an offense, but not a sin"