Re: problems with 1.0.3 and color scanning

From: Steve Underwood (steveu@coppice.org)
Date: Thu Sep 21 2000 - 07:48:15 PDT

  • Next message: Lawrence Glaister: "Re: problems with 1.0.3 and color scanning"

    Lawrence Glaister wrote:

    > I am trying to get sane 1.0.3 working with my snapscan 1212u usb scanner.
    > The scanner works properly under 1.0.1 but fails in various ways under 1.0.2
    > and 1.0.3 and the cvs code as of sept 19. I have narrowed the problem down
    > to the snapscan-sources.c RGBRouter_remaining() function.
    > - grayscale scanning works fine
    > - color scanning a small image at 50dpi works
    > - color scanning same image at 75dpi breaks xscanimage
    > by broken, I mean that xscanimage enters into an infinite loop using 100%
    > cpu time.
    > the cause for this appears to be a negative result returned by
    > RGBRouter_remaining(). There are two possible return values calulated in
    > RGBRouter_remaining() and one of them always looks like the correct
    > answer... the problem comes in that the conditional used doesn't seem to
    > work in all cases (sometimes the wrong value is returned and when this
    > is -ve, all hell breaks loose.). I have been getting a headache trying to
    > decipher how the new RGBRouter code is supposed to work... could the author
    > (pere) or someone have a look at the function and see if they see any
    > obvious errors. I have not seen a lot of postings about 1.0.3, so the
    > problem may be related only to the snapscan backend with a usb patch applied
    > to it.
    > I can supply some rather detailed dumps of the good scans and bad scans as I
    > have added a lot of dbg calls into the snapscan code.
    >
    > Are there any snapscan scanners usb or scsi out there working with sane
    > 1.0.3???

    Excellent. This look likes a really solid lead for what goes wrong. I will try
    to look at the RGBRouter code in the next couple of days, and see if I can spot
    what goes amiss. Actually, I thought the current RGBRouter code was fairly
    straightforward, but maybe that's only to my own twisted mind! The existing
    code certainly does work for some scanners. It works just fine for my Acer
    610+, and a few other people have reported success with some scanners.

    Lets hope this is the root cause of several not quite identical problems people
    have reported.

    If you have any debug logs, or other useful info please mail it to me. my code
    hasn't given me any trouble so far, so a log of an actual failure would be
    helpful.

    Steve

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