[Spice-devel] Video buffering

[Marian Krcmarik]

Hi John,

Could you please specify more your setup? Maybe It would be useful to know more about your setup so that we have better idea and can reproduce easier. The best is to know in what setup you observe particular problems. I mean things such as: host, qemu (its cli), spice-server, spice client, guest (window manager), qxl driver, environment (WAN?, latency, bandwidth) etc.
You mentioned several problems:
- Xorg process hits 100% (F15 on F15), Do you still observe that problem, I can see you are testing other stuff (video, office work..) so It means you solved it? How? If not what setup is it? can you hit that on other guests (Windows?) In case you hit that on Linux can you provide profile from sysprof tool or output of perf top?

- scrolling, typing. I suppose It was observed in WAN (what exactly?)? were jpeg/zlib over glz options enabled? Can you provide the webpage you tested on?

- video, before you mentioned you were amazed by video performance, Did you change anything in your setup? It's the WAN? I can see that Attila has acceptable experiences with video performance but he mentioned he was using 0.4 spice-server (I've read in his replies somewhere recently, I hope), If you have time and available host, you can try to compare 0.4 and 0.8 spice server when playing video and report back:).

Thank you

----- Original Message -----
> From: "John A. Sullivan III" <jsullivan at opensourcedevel.com>
> To: "Attila Sukosd" <attila.sukosd at gmail.com>
> Cc: spice-devel at freedesktop.org
> Sent: Saturday, June 18, 2011 9:59:12 PM
> Subject: Re: [Spice-devel] Video buffering
> On Sat, 2011-06-18 at 21:26 +0200, Attila Sukosd wrote:
> > Hi John,
> >
> > Did you check the guest cpu usage while playing back youtube?
> >
> > We have noticed that the bad video playback performance with flash
> > was
> > due to it using up all of the guest CPU, and of course it does not
> > improve a lot by giving the VM more cores either... (ok this was on
> > a
> > 12 core AMD, where the cpu speed isn't as high per core as for other
> > cpus)
> >
> > Switching to HTML5 playback on youtube gave about the same video
> > performance as playing it with VLC, and we could play back 720p over
> > a
> > 15mbit DSL line with an acceptable overall performance.
> <snip>
> 
> It doesn't seem to be. Here are some stats and examples:
> 
> http://www.youtube.com/watch?v=vb8njeKBfqw&feature=related
> 8-15% Flash 8-32% HTML5
> http://www.youtube.com/watch?v=6eM8bXW3fhU&playnext=1&list=PL3CB56EAD33DEBAA6
> 5-18% Flash 9-32% HTML5
> http://www.youtube.com/watch?v=tH-EVMUCsZc&feature=related
> 4-20% Flash 10-41% HTML5
> 
> As soon as something covers the video, we are able to take advantage
> of
> SPICE's not writing hidden space and the audio picks right up. As soon
> as the video is exposed, it starts sputtering again. Thanks - John
> 
> >
> > On Sat, Jun 18, 2011 at 8:17 PM, John A. Sullivan III
> > <jsullivan at opensourcedevel.com> wrote:
> > > Hello, all. We spent some time testing audio and video performance
> > > with
> > > SPICE today with mixed results. Talking heads and some movement
> > > were
> > > reasonably acceptable. However we tried some music and ballet
> > > videos to
> > > get lots of movement and the results were unusable - Rite of
> > > Spring was
> > > more like Frozen Ice of Winter. These were not full screen -
> > > simple
> > > YouTube type video using an cable Internet connection - several
> > > Mbps
> > > download, a couple upload.
> > >
> > > We are thus thinking of pursuing our plans to wrap SPICE inside
> > > X2Go so
> > > we can use the new mimebox facility and offer users the choice of
> > > either
> > > the streaming SPICE video approach or the more Citrix like
> > > download and
> > > play locally approach.
> > >
> > > I'm guessing the problem is buffering. If the pipe isn't big
> > > enough, it
> > > just isn't going to get through in a usable way - stuttering and
> > > starting all over the place. Are there any plans to build some
> > > sort of
> > > buffering into SPICE when it detects a video stream?
> > >
> > > I'm sure many are thinking likewise but we are looking at video as
> > > not
> > > just a technology shift but a huge long term cultural shift almost
> > > as
> > > large as the printing press so we see any VDI solution which does
> > > not
> > > address video despite the huge technical hurdles as inadequate.
> > >
> > > We have already been told by some schools that they could not use
> > > our
> > > X2Go VDI model because of their need for video. Likewise, adoption
> > > has
> > > been delayed by some large PR / Communications companies because
> > > of a
> > > lack of video support. As we look at consumerization of VDI for
> > > potential service to lower income users, video is a potential show
> > > stopper.
> > >
> > > Enough of teaching Grandma to suck eggs but this is why we are so
> > > enthusiastic about SPICE - at least it has a fighting chance with
> > > video.
> > > So we look forward to integrating with X2Go and would love to know
> > > if
> > > there is a plan (or even an existing way) to implement buffering
> > > in
> > > SPICE. Thanks - John
> > >
> > > _______________________________________________
> > > Spice-devel mailing list
> > > Spice-devel at lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/spice-devel
> > >
> 
> 
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