[mythtv-users] mythfrontend performance over x11vnc

[James Linder]

> On 17 Mar 2022, at 7:34 am, Ram Ramesh <rramesh2400 at gmail.com> wrote:
> 
> On 3/16/22 16:38, Dave Ulrick wrote:
>> I have two Intel NUC boxes that I use to run mythfrontend under Fedora 34. I like to do most administration remotely using x11vnc. (That way I can use an ergonomic keyboard and sit in front of a monitor that's within good viewing distance...much more comfortable than using a wireless keyboard while trying to look at a distant TV.)
>> 
>> Sometimes remote control is nearly as fast as it would be to control the box locally--the OpenGL fade effects look pretty good and recording playback is very close to optimal--but other times it's extremely slow: > 1 second delay for response to any keystroke. Once the slow behavior kicks in, it persists from one x11vnc session to another until mythfrontend is restarted or the box's monitor (TV) is turned on.
>> 
>> Note that the x11vnc slowness occurs even if I implement the solutions recommended for slowness issues: set -noxdamage, disable desktop compositing, disable vblank, etc..
>> 
>> Just now I figured out how this issue occurs:
>> 
>> 1. The remote PC's monitor is turned off.
>> 2. The screensaver on the remote PC has blanked the screen.
>> 3. x11vnc is invoked.
>> 4. The VNC viewer connects and shows a blank screen.
>> 5. Pressing a key brings the screen to life but from then on mythfrontend is very slow via x11vnc.
>> 
>> My guess as to what's going on is that when the PC turns off the monitor, the X server loses sync so x11vnc falls back on a timeout-driven refresh scheme.
>> 
>> I have come up with a simple solution.
>> 
>> In my use case, I only have a monitor--that is, an HDTV switched to an HDMI input--turned on when I'm watching MythTV content. Otherwise, the monitor is turned off. Therefore, there's no need to run a screen saver. I didn't find a quick way to stop the screensaver (xfce4-screensaver) from running so I just went ahead and removed it from the boxes (dnf remove xfce4-screensaver).
>> 
>> Since removing the screensaver, the screen hasn't blanked so mythfrontend has retained fast performance over VNC.
>> 
>> Hope this helps someone out...
>> 
>> Dave
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> 
> Interesting. Without knowing this dependency, I have screensaver uninstalled because the only monitor is TV and it is off in my case when I am not actively using it. However, my x11vnc is always slow from one machine and always reasonable from another machine (connected to two different TVs)
> 
> I noticed that when I boot without turning on TV, my X is 640x480. I have to do xrandr --fb 1920x1080 to get it big or turn on the TV. When this happens I have seen slowness also. So best to turn on TV, remove screensaver and boot the PC.

If you want to be, as linus argues, pragmatic then nomachine works well and audio is no problem

Jamws