TV Recording System Specification


Design goals
  • Watch TV programs broadcast in Japan on a large screen TV in family room in the U.S.
  • Remotely and securely control everything over the Internet
  • Use of and connectivity with open source resources.
Installation December 2005
Availability 99.9% (actual, excluding scheduled downtimes)

Base recording server installed in downtown Tokyo

CPU AMD Sempron(tm) Processor 3000+ (1.8GHz)
Memory 512MB (64MB used for VGA) DDR3200
Disk 100GB SATA/150, 8.5GB IDE (for local backup)
TV capture cards Haupauge PVR350 with hardware MPEG2 encoding (2 ea.)
UPS A dumb UPS (no communication with server) prevents the server from power-cycling at a short period of power outage
Hardware cost ~ $600US
OS Linux 2.6 (Fedora Core 4)
Control and processing software
  • Various open source tools including ffmpeg
  • Home-brew programs written in PHP, Perl, and Bash


Scheduling iEPG with point-and-click on a commercial TV guide site using URL-wrapping technology
Regular programs Day of week, Monday-Friday
TV stations VHF analog (1-12ch)
Simultaneous recording Up to 2 programs with automatic arbitration of TV capture cards
Primary recording MPEG2 720x480i 29.97fps NTSC 8Mb/s (3.9GB/h with audio)
Transcoding MPEG4 640x480i 29.97fps NTSC 2Mb/s (966MB/h with audio)
Audio Monaural, 128kbps after transcoding
Transcoding performance About 220% of program time (software transcoding with ffmpeg)
Simultaneous transcoding A significantly shorter program can cut in with a higher priority (no more than 2 simultaneous transcoding processes)

Recorded program transfer

File transfer Rsync over SSH (possible to resume interrupted transfers, no file size limit, one program at a time, shortest program first)
File transfer performance Up to 490kB/s (limited by local cable downstream)
Internet security Packet filtering, SSL, server access deny/allow list

Play back

TV Sony KDF-50WE655 50" LCD RPTV
Network Media Player Buffalo "Link Theater" PC-P3LAN2/DVD
Resolution 640x480i on 720p screen
NMP server (hardware) Pentium 4, 3GHz, 1GB memory, 1.2TB disk, Linux 2.6 (Fedora Core 5)
NMP server (software) Wizd (modified)
Program menu Date, Time, Program title, Program subtitle, Station, File size
File management Delete, Archive (web based)
Playback quality Similar to good VHS