[Spice-devel] Very poor video performance using Virt Viewer compared to RDP

[Francois Gouget]

On Mon, 17 Oct 2016, Brad Wilson wrote:

> Ok, so I installed the AC97 audio drivers to fix my audio device in 
> the guest vm.  Using Virt-Viewer with qxl, the video streaming has 
> improved and I am seeing closer to 1.5Mbps network traffic now when 
> watching hd videos but the quality is still suffering a bit.  What I 
> would like to know is if there is a way to allow the spice protocol to 
> use more bandwidth in order to increase video quality and frame rate. 
>  In windows RDP you can set the quality to be super high which gives a 
> much nicer video experience at the cost of about 15Mbps... I am 
> curious if Spice or Virt-Viewer have such a setting? And just to be 
> clear, I can get near native quality using rdp to this same VM. 

There is no such setting. Spice automatically uses all the available 
bandwidth.

That said if for some reason it settled on a bandwidth lower than what 
is truly available, it will only try to increase bandwidth usage again 
after a while and only quite progressively (at least for the GStreamer 
backend, I don't really remember what the mjpeg one does in that case).


-- 
Francois Gouget <fgouget at codeweavers.com>