Compact MythTV Frontend

1
Compact MythTV Frontend
Advisor Professor Wilsey
David Kesler
Dustin Grimmeissen
Richard Anderson
2
MythTV

• Open source software intended to replace TIVO and
  other proprietary DVR systems
• Runs on a Linux machine storing video and other
  media to the hard drive
• Media can be played back from hard drive
• Can have multiple frontends serving media off a
  dedicated backend

3
MythTV Problem

• Users may not want to purchase a PC to sit next
  to their TVs
• PCs are large and often unsightly
• Separate frontend/backend allows for a small, low
  power computer by the TV
• Small general purpose computer are expensive

4
Desired Features

• MythTV communicating and playing video from a
  backend
• NTSC output on an S-Video cable to a television
• Finished product size of approximately 50 cubic
  inches

5
Accomplishments

• Software
• An x86 Gentoo image less than 64 mb
• With MythTV Frontend Compiled
• A compiled Gumstix image with
• Framebuffer and core system drivers lt 10 mb
• X-Windows server
• DirectFB Graphics Library
• SDL Graphics Library
• Sample Framebuffer Graphics Applications

6
Accomplishments

• Hardware
• Board capable of converting digital RGB signals
  to drive a VGA monitor
• Successfully connected the board to the Gumstix,
  displaying the contents of the framebuffer on a
  VGA monitor
• Hardware meets space requirements

7
Design Process

• Base system
• Used Gumsitx as the base system
• Features
• 400 MHz ARM Processor
• 64 MB of RAM
• 16 MB of internal storage
• MMC/SD Slot for high capacity permanent storage
• Built in Ethernet and audio capability
• Why
• Extremely small form factor
• Low power, heat, and noise
• Several features built in

8
Design Process

• Software
• Compiled Linux image using Gentoo for x86
  architecture, with MythTV frontend included.
• Attempted building Gentoo image for ARM
  processor, but found MythTV to be infeasible.
• Created Gumstix image from scratch, manually
  building framebuffer drivers and core system
  programs.
• Compiled and installed framebuffer testing
  applications to Gumstix.
• Compiled and installed DirectFB and SDL graphics
  libraries for future development.

9
Design Process

• Hardware
• Initial design planned on utilizing Sigma Designs
  EM8620L or similar graphical processing unit
• Second plan involved converting the Gumstix LCD
  controller output to S-Video
• Created circuit board utilizing Analog Devices
  ADV7120 and AD723
• Intended to interface with Gumstix through a CPLD
  downsampler / interleaver

10
Hardware Design

• Discovered output of ADV7120 can directly drive a
  VGA monitor
• Successfully interfaced ADV7120 with Gumstix and
  VGA monitor

• Initial Test Display colored bars using signals
  generated from a CPLD
• Could not generate proper NTSC signal

11
Conclusion

• With further work it may still be possible to
  convert the Gumstix LCD controller signals to an
  NTSC signal
• Due to the limitations of 16-bit color running
  MythTV or a movie player may not result in
  acceptable video quality
• Due to cross-compilation difficulties, getting
  MythTV to run on an ARM processor may be
  unfeasible anyway
• Compiled graphics libraries may allow for other
  media players to be compiled and executed in
  place of MythTV