MythTV Build Seminar Presenter: Matt Mossholder

Topics MythTV Overview Component selection Design Decisions Q&A

What is MythTV? MythTV Overview Master Backend Slave Backends Frontends Alternatives

Master Backend Responsible for: Scheduling Downloading Guide Data Optionally responsible for: Recording programs Commercial Flagging Transcoding Waking up slaves

Slave Backends Provide off-load for the master Recording programs Commercial Flagging Transcoding Do NOT provide: Scheduling, download of Guide Data

Frontends Frontends are used to interact with users Handles all audio/video playback Provides access to plugins

Alternatives Haupagge MVP small settop box that can interface directly with MythTV using alternate firmware (MVPMC) UPNP Devices Some Media Extenders work with newer versions of MythTV for playback of recordings/music/videos (No LiveTV!)

Alternatives II Original Xbox MythTV FE has been ported to hacked Xboxes AppleTV Ported here as well

Component Selection Component selection Video Capture devices Processor Hard Drives Remote Controls Video Cards (nVidia, ATI, Intel, VIA)

Video Capture Devices 3 Options Dumb Smart HD

”Dumb” Video Capture Also known as ”Framegrabbers” Deliver uncompressed video to the system MythTV handles all compression Requires a faster processor

”Smart” Video Capture Compress video data before delivery to MythTV Primary compression options are MPEG-2 and MPEG- 4 MPEG-2 is the most widely available, and best supported Less impact on the system than Dumb video capture. Currently available for PCI, USB

HD Capture devices Different from Smart and Dumb – more like a modem All compression is performed by the broadcaster prior to transmission All compression is MPEG-2, per ATSC standard Works with Over-The-Air(OTA) and Cable(QAM64/256) Available for PCI, USB and Network

Processor Selection Largely dependant on content (HD vs. SD) Intel v.s. AMD is mostly a non-issue Multi-core can smooth out playback (more when we get to design decisions!)

Hard Drive Selection Capacity dependant on how much content you want to keep online RAID can enhance (and hurt!) performance Speed isn't as much of an issue as you might think (example: 4800RPM drives in the original TiVo)

Remote Control Selection Universal Remote Programable Remotes Cheating with Wireless Keyboards

Universal Remotes Universal Remotes can emulate a number of other remotes (+)Pick a remote that has the buttons you want, and emulate it (-)Need to ensure that Linux IR system (LIRC) supports the emulated remote (-)Issues with button labels

Programable Remotes Programable remotes allow you to determine what each key does Some are programed via the remote itself, some via a computer (+)Control multiple devices (e.g. TV, stereo, MythTV) (+) Better button control (-) More expensive

Cheating with Wireless Keyboards Some people don't want to use LIRC. Instead, they buy an IR Wireless keyboad, and then capture the keystrokes with a learning Remote. (+) Less complexity (+) Wireless keyboards/mice are handy for some plugins (e.g. MythBrowser) (-) Keymaps may differ between applications

Video Card Selection Current de facto choice: Almost anything nVidia AMD/ATI recently opensourced specs and drivers, which may change the landscape Intel is catching up, but not ready for HD Via works well with low power systems

Design Decisions Combined Frontend/Backend, or separate components? Disk based FE or Diskless? Wired or Wireless? Standard Definition or High Definition? RAID? Storage Groups?

Combined Frontend/Backend? Advantages: Less complex Cost Disadvantages Larger computer near TV (i.e. noise, space) Backend processing may interfere with playback

Disk-based FE or Diskless Diskless Advantages Reduced noise, heat Disadvantages Complex to implement Exagerates network issues

Wired or Wireless Avoid wireless when possible SD over wireless is more likely to work than HD Outside devices may impact signal quality (e.g. microwaves, cordless phones) Issues that aren't appearant surfing the net become glaringly obvious on your TV!

Standard or High Def? HD is here today, but not widespread Largely based upon the viewing device HD is moderately more expensive than SD (larger drives, faster processors, more RAM, display)

RAID? Not an issue with a single tuner, unless you want more space Multiple tuners punish disks with long duration ”random” writes RAID 1+0 best for multi-tuner recording drives RAID 5 best for long term storage

Storage Groups? Storage Groups allow recordings to reside on any of a group of disks. Myth will look for a recording on each drive of a group, and play the first instance found. Advantages over RAID: multiple filesystems provide better protection from filesystem corruption, less complex to implement Disadvantages over RAID: splitting drive load is up to the user