Re: Snapscan.... Help! (a few extra data)

From: Steve Underwood (steveu@coppice.org)
Date: Wed Dec 20 2000 - 10:25:06 PST

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    John Coppens wrote:

    > Hi Chris.
    >
    > A few (possibly) hints...
    >
    > I've been checking the debug log and found a few strange things.
    >
    > - Says buffer is size = 31725 bytes, 55 lines. At 1269 bytes/lines this
    > can't be (should be 25). I checked the source code and found:

    Have you allowed for the chroma offset ring-buffer?

    > DBG (DL_DATA_TRACE,
    > "%s: effective buffer size = %lu bytes, %lu lines\n",
    > me,
    > (u_long) pss->buf_sz,
    > (u_long) (pss->buf_sz ? pss->buf_sz / pss->lines : 0));
    >
    > I suppose this should be / pss->bytes_per_line

    Yes, this looks like a silly slip.

    > - A bit before that, it says : set_window: bits-per-pixel set to 30
    >
    > How can this result in 3 bytes/pixel afterwards? I couldn't find
    > how the extra 2 bits (*3) are sent... Are they packed in another block?

    The scanner is using 30 bits, but after gamma correction it only outputs 24 bits to the host. This is normal behaviour for a 30 bit
    scanner.

    Regards,
    Steve

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