[Spice-devel] Spice console pixelated noise on display changes

[Frediano Ziglio]

> 
> Hi,
> 
> On Wed, Jun 13, 2018 at 10:11:00AM +0200, Mitja Mihelič wrote:
> > Dear all,
> >
> > We are running the following setup:
> > ovirt-engine host:
> > - CentOS release 7.5.1804
> > - ovirt-engine-4.1.9.1-1.el7.centos.noarch
> > - spice-html5-0.1.7-1.el7.noarch
> >
> > We have noticed problems with the Spice console. When it opens
> > and displays the information presented by the VM's console it
> > is OK at first. But as soon as any part of the display changes,
> > that part gets replaced by random pixelated noise.
> > For example I open the console of a standard CentOS server.
> > When I type something at the login prompt the text is invisible
> > and random pixels are displayed at the position of the blinking
> > cursor. Please see attached screenshot
> > spice-1-login_typing_and_cursor_waiting.png.
> >
> > Please also see other the attached screenshots.
> > Login prompt after VM reboot: spice-2-login_after_boot.png
> > Login prompt after hitting Enter a few times: spice-3-login_2x_enter.png
> >
> > We have tried and succesfully reproduced the issue on OSX (Chrome, FF,
> > Safari) and Windows (Chrome, FF).
> > VNC works fine.
> 
> Does it work fine with remote-viewer?
> 
> You could try different image compression too,
> e.g image-compression=off
> https://people.freedesktop.org/~teuf/spice-doc/html/ch03.html
> 
> Cheers,
>         toso
> 
> > Why would this be happening? Help would be very much
> > appreciated.
> >
> > Kind regards,
> > Mitja
> > 

I would also try to download a new version of spice-html5 and use
it directly to see if the problem is fixed.

Note that you can set image compression using libvirt like

  <graphics type='spice' port='5901' autoport='no'>
    <image compression='auto_glz'/>
  </graphics>

(note the "image" element inside "graphics").

Frediano