Having got ArchLinux up and running on the TonidoPlug 2 it was a trivial matter in the extreme to get a functioning MythTV backed up and running. Installing the packages was straightforward and simply done via the standard package manager - pacman.
The only minor problem with the setup and configuration is how on earth you run the setup without a display. Thankfully it's easy and you can simply rely on X11 forwarding.
Recording a single SD show results in an ~30% CPU usage load, which I am more than happy with for now. I've not ventured into trying to record HD signals yet so the plug may not be up to the job, but we shall see.
The only thing that is currently causing a problem is thumbnail icons in MythWeb. It looks like the icons are generated on demand and on the plug each icon takes a fair while - several seconds.
Due to multiple requests being made to MythWeb the plug ends up trying to generate several icons at the same time and ends up getting overwhelmed. The requests end up timing out and hence the icon generation gets stopped. The end result of all of this is that no icons show in the browser and no icons ever getting generated as the requests get terminated.
Partial Solution ∞
It is pretty straightforward to manually generate an icon for a particular show:
mythpreviewgen --infile infile.mpg
MythWeb generates three differently named thumbnail icons at different sizes. Using
convert the command line image toolkit from ImageMagick the other icon sizes can easily be generated.
MythTV allows you to execute commands when events occur. By wrapping the above code into a small shell script we can make use of the recording finished event to generate a MythWeb icon. The shell script is:
#!/bin/sh i=$1 mythpreviewgen --infile $i convert -resize 100x56 $i.png $i.-1.100x56.png convert -resize 320x180 $i.png $i.-1.320x180.png
So now it's possible to bypass MythWeb and generate icons when a recording is finished via MythTV events. Unfortunately this doesn't entirely solve the problem - even when the icons exist MythWeb seems to take an absolute age to retrieve the thumbnails. Something that needs to be looked into further.
I use MythWeb exclusively for scheduling and managing recordings and it's pretty snappy - the thumbnail icon problem aside. It's not instantaneous, but certainly plenty fast enough not to be an issue although I've never had a MythTV backend running on anything powerful so I have no direct frame of reference.
All in all I now have a MythTV backend that draws 1.2W of power, which I am more than happy to leave running 24/7.