[FreeNX-kNX] vnc session does not work

[Doug Burks]

Hi Gian Filippo,

On Tue, 19 Oct 2004 17:08:37 +0200, Gian Filippo Pinzari
<pinzari at nomachine.com> wrote:
[snip]
> Probably nxviewer doesn't get all the attention it deserves from
> NoMachine, but that's just because we don't have the resources
> to develop all the agents at the same level.

I wasn't complaining about nxviewer or NoMachine; I understand that
VNC sessions aren't really the core mission of NoMachine.  We (the
FreeNX community) all thank you for your generous contributions!

> > I, personally, would like to see an
> > nxviewer that could auto-scale the VNC session for times when you're
> > on a machine with a resolution of 800x600 and you're connecting to a
> > VNC server with a resolution of 1024x768 (see UltraVNC viewer for
> > example).
> 
> Me too.
> 
> >>are there any performance gains using the tight-stuff compared to the
> >>"Use X plain bitmaps" (using the nxclient of course)?
> 
> NX agents work in a way that the original RFB or RDP packets are
> transmitted to the local proxy unmodified, so that the agent doesn't
> have to re-encode them on the server. The packets are still subject
> to all the NX encoding techniques, including caching. Actually the
> RFB packet (Tight, Hextile, etc.) is just another "pack method" of
> the PutPackedImage message. High-level X protocol messages are sent
> (and compressed) whenever the original viewer sent plain X protocol,
> so, depending on how cacheable are the RFB packets and how much addi-
> tional X traffic is used by the viewer, the compression can be signi-
> ficant. In the worst case, compression is slightly better than with
> the original viewer (due to the residual compression of the X protocol)
> but with no performance penalty (as the packet is only uncompressed
> on the local client).
> 
> Setting the encoding to plain bitmaps, NX has to decode the bitmap
> on the agent/viewer and then compress it again. This is going to waste
> CPU cycles compared to handling the RFB packets in their original
> format, so the best option is to fix nxviewer to handle the missing
> encodings.

Thanks for the in-depth info!  I'll begin looking at the nxviewer
sources to see if that's a project that I might be able to tackle.

Doug