sane-project-website/old-archive/2000-12/0241.html

189 wiersze
6.5 KiB
HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
"http://www.w3.org/TR/REC-html40/loose.dtd">
<HTML>
<HEAD>
<TITLE>sane-devel: Re: Snapscan.... Help! (a few extra data)</TITLE>
<META NAME="Author" CONTENT="John Coppens (jcoppens@linux2.uccor.edu.ar)">
<META NAME="Subject" CONTENT="Re: Snapscan.... Help! (a few extra data)">
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Re: Snapscan.... Help! (a few extra data)</H1>
<!-- received="Wed Dec 20 18:46:00 2000" -->
<!-- isoreceived="20001221024600" -->
<!-- sent="Thu, 21 Dec 2000 00:00:20 -0300" -->
<!-- isosent="20001221030020" -->
<!-- name="John Coppens" -->
<!-- email="jcoppens@linux2.uccor.edu.ar" -->
<!-- subject="Re: Snapscan.... Help! (a few extra data)" -->
<!-- id="200012210300.AAA15047@linux2.uccor.edu.ar" -->
<!-- inreplyto="3A40F982.C6D88520@coppice.org" -->
<STRONG>From:</STRONG> John Coppens (<A HREF="mailto:jcoppens@linux2.uccor.edu.ar?Subject=Re:%20Snapscan....%20Help!%20(a%20few%20extra%20data)&In-Reply-To=&lt;200012210300.AAA15047@linux2.uccor.edu.ar&gt;"><EM>jcoppens@linux2.uccor.edu.ar</EM></A>)<BR>
<STRONG>Date:</STRONG> Wed Dec 20 2000 - 19:00:20 PST
<P>
<!-- next="start" -->
<LI><STRONG>Next message:</STRONG> <A HREF="0242.html">Ian Cartwright: "RE: Snapscan.... Help! (a few extra data)"</A>
<UL>
<LI><STRONG>Previous message:</STRONG> <A HREF="0240.html">Jerry Fritschle: "Re: Sg devices on Mac hardware."</A>
<LI><STRONG>In reply to:</STRONG> <A HREF="0239.html">Steve Underwood: "Re: Snapscan.... Help! (a few extra data)"</A>
<!-- nextthread="start" -->
<!-- reply="end" -->
<LI><STRONG>Messages sorted by:</STRONG>
<A HREF="date.html#241">[ date ]</A>
<A HREF="index.html#241">[ thread ]</A>
<A HREF="subject.html#241">[ subject ]</A>
<A HREF="author.html#241">[ author ]</A>
</UL>
<HR NOSHADE><P>
<!-- body="start" -->
<P>
Hello Steve.
<BR>
<P>Thanks for the info. If only I could find a source for this data, I wouldn't
<BR>
bother the list with such basic questions.
<BR>
<P>Anyway, I experimented a bit more, but I cannot find a way to get the
<BR>
color organized. As I wrote a mail before, the image appears, in different
<BR>
colors, displaced horizontally. Something like
<BR>
should be Is
<BR>
<P>aaabbbcccddd aaabbbcccddd
<BR>
aaabbbcccddd abbbcccdddaa
<BR>
aaabbbcccddd cccdddaaabbb
<BR>
aaabbbcccddd daaabbbcccdd
<BR>
<P>note: these stripes are 5 to 50 scan lines wide...
<BR>
<P>And colors are changing too. It seems to have something to do with the
<BR>
machine's activity at the moment: the horizontal stripes are wider with
<BR>
less activity. It's a bit difficult to describe in words.
<BR>
<P>I have the impression there's some data loss at the beginning of the
<BR>
transferred block... Any way to test this?
<BR>
<P>John
<BR>
<P>On Thu, 21 Dec 2000 02:25:06 +0800 Steve Underwood &lt;<A HREF="mailto:steveu@coppice.org?Subject=Re:%20Snapscan....%20Help!%20(a%20few%20extra%20data)&In-Reply-To=&lt;200012210300.AAA15047@linux2.uccor.edu.ar&gt;">steveu@coppice.org</A>&gt; wrote/El dddd&gt; John Coppens wrote:
<BR>
<EM>&gt;
</EM><BR>
<EM>&gt; &gt; Hi Chris.
</EM><BR>
<EM>&gt; &gt;
</EM><BR>
<EM>&gt; &gt; A few (possibly) hints...
</EM><BR>
<EM>&gt; &gt;
</EM><BR>
<EM>&gt; &gt; I've been checking the debug log and found a few strange things.
</EM><BR>
<EM>&gt; &gt;
</EM><BR>
<EM>&gt; &gt; - Says buffer is size = 31725 bytes, 55 lines. At 1269 bytes/lines this
</EM><BR>
<EM>&gt; &gt; can't be (should be 25). I checked the source code and found:
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; Have you allowed for the chroma offset ring-buffer?
</EM><BR>
<P>Mmmm... how much space does this occupy? And why is the effective
<BR>
space calculated without subtracting this space first?
<BR>
<P><EM>&gt;
</EM><BR>
<EM>&gt; &gt; DBG (DL_DATA_TRACE,
</EM><BR>
<EM>&gt; &gt; &quot;%s: effective buffer size = %lu bytes, %lu lines\n&quot;,
</EM><BR>
<EM>&gt; &gt; me,
</EM><BR>
<EM>&gt; &gt; (u_long) pss-&gt;buf_sz,
</EM><BR>
<EM>&gt; &gt; (u_long) (pss-&gt;buf_sz ? pss-&gt;buf_sz / pss-&gt;lines : 0));
</EM><BR>
<EM>&gt; &gt;
</EM><BR>
<EM>&gt; &gt; I suppose this should be / pss-&gt;bytes_per_line
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; Yes, this looks like a silly slip.
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; &gt; - A bit before that, it says : set_window: bits-per-pixel set to 30
</EM><BR>
<EM>&gt; &gt;
</EM><BR>
<EM>&gt; &gt; How can this result in 3 bytes/pixel afterwards? I couldn't find
</EM><BR>
<EM>&gt; &gt; how the extra 2 bits (*3) are sent... Are they packed in another block?
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; 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
</EM><BR>
<EM>&gt; scanner.
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; Regards,
</EM><BR>
<EM>&gt; Steve
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt;
</EM><BR>
<EM>&gt; --
</EM><BR>
<EM>&gt; Source code, list archive, and docs: <A HREF="http://www.mostang.com/sane/">http://www.mostang.com/sane/</A>
</EM><BR>
<EM>&gt; To unsubscribe: echo unsubscribe sane-devel | mail <A HREF="mailto:majordomo@mostang.com?Subject=Re:%20Snapscan....%20Help!%20(a%20few%20extra%20data)&In-Reply-To=&lt;200012210300.AAA15047@linux2.uccor.edu.ar&gt;">majordomo@mostang.com</A>
</EM><BR>
<P><P><PRE>
--
<P>--
Source code, list archive, and docs: <A HREF="http://www.mostang.com/sane/">http://www.mostang.com/sane/</A>
To unsubscribe: echo unsubscribe sane-devel | mail <A HREF="mailto:majordomo@mostang.com?Subject=Re:%20Snapscan....%20Help!%20(a%20few%20extra%20data)&In-Reply-To=&lt;200012210300.AAA15047@linux2.uccor.edu.ar&gt;">majordomo@mostang.com</A>
</PRE>
<P><!-- body="end" -->
<HR NOSHADE>
<UL>
<!-- next="start" -->
<LI><STRONG>Next message:</STRONG> <A HREF="0242.html">Ian Cartwright: "RE: Snapscan.... Help! (a few extra data)"</A>
<LI><STRONG>Previous message:</STRONG> <A HREF="0240.html">Jerry Fritschle: "Re: Sg devices on Mac hardware."</A>
<LI><STRONG>In reply to:</STRONG> <A HREF="0239.html">Steve Underwood: "Re: Snapscan.... Help! (a few extra data)"</A>
<!-- nextthread="start" -->
<!-- reply="end" -->
<LI><STRONG>Messages sorted by:</STRONG>
<A HREF="date.html#241">[ date ]</A>
<A HREF="index.html#241">[ thread ]</A>
<A HREF="subject.html#241">[ subject ]</A>
<A HREF="author.html#241">[ author ]</A>
</UL>
<!-- trailer="footer" -->
<HR NOSHADE>
<P>
<SMALL>
<EM>
This archive was generated by <A HREF="http://www.hypermail.org/">hypermail 2b29</A>
: <EM>Wed Dec 20 2000 - 18:50:40 PST</EM>
</EM>
</SMALL>
</BODY>
</HTML>