Low Power MYTHTV Architecture

I have implemented a low power, “instant on” architecture for my MYTHTV implementation. Some highlights:

  • The system restores to an “on” state in less time than it takes for my Plasma TV to “warm up”.
  • Average hourly power consumption across all components is 35 watts, inclusive of the power required to transcode all recordings to XVID.
  • The user interface experience is top flight.
  • Video playback quality is superb for 720p and 1080i myth recordings.
  • Hulu playback suffers some minor tearing. I am told by Adobe that upgrading from Windows XP to Vista or W7 will solve this problem.
At a high level the system consists of 3 boxes:

 Recording & Transcoding Engine

Only powered up when recording or transcoding.
 Front end for playback

Only powered up when watching a show
Storage Platform

Runs 24x7. Draws very little power.

I have drawn a more detailed architecture diagram here.

High level Setup

This setup guide assumes that you already familiar with MYTHTV and XBMC. I am using the KNOPPMYTH (now LINHES) distribution for MYTHTV:
  • Purchase a D-link DNS-321 Network Attached Storage unit (NAS) and populate with disk drives.
    • Other NAS units will work, but this unit has sufficient performance and can be purchased for as little as $90, after rebate.
  • Install mythtv on your backend machine.
    • Configure so that all recordings are made to the D-link NAS instead of local storage.
  • Install XBMC on your frontend machine. 
  • Install xbmc_mythlink.py on your mythtv machine and configure your backend and frontend machines, as described here
Recording to the NAS

The NAS draws very little power, so it can run 24x7 and your frontend will have access to your recordings even when the mythtv backend is powered down. These steps are required to mount the NAS on your mythtv box
  • Add an appropriate entry to the end of/etc/fstab:
    • //NAS_IP_ADDRESS/NAS_SHARE_NAME /Local_mount_point cifs rw,exec,uid=mythtv,gid=mythtv,soft,password= 0 2
  • My machine would not automatically mount the storage on re-boot so I had to add the following at the end of /etc/init.d/bootmisc.sh:
    • mount -av
  • You need to configure mythtv to record to the networked storage. There are two approaches
    • Use mythtv-setup to configure your storage group to record to "/Local_mount_point".
    • If you are running Knoppmyth, you can replace the directory "/myth/tv" with a symbolic link points to /Local_mount_point" with the following commands
      • rmdir /myth/tv
      • ln -s /Local_mount_point /myth/tv
Left to document

Additional information that will be added in the future:
  • Backend
    • Automated shutdown of backend.
    • Keep drives spinning when backend is running.
  • Frontend on WIndow XP
    • How to configure DSplayer
    • eventghost for the remote
    • Hulu deskptop

Subpages (1): Arch Diagram