Digital Software

Operating system

I chose the Fedora 14 distribution (FC14) of Linux because I have been using RedHat distributions of Linux for a long time since the RedHat 5, if my memory still serves, and I have several in-house system administration tools in my inventory (my first serious Linux experience was Slackware). These days  many software developers prefer Ubuntu. In fact, I have been using Ubuntu desktop editions at my workplaces for the last four years. Either distribution has its own pros and cons, but my personal impression is that the Fedora is better for server type applications while Ubuntu is good for desktop and workstation applications. Fedora's System V style RC scripts are very orthogonal and each subsystem is well-defined. This makes system administration very clear while Ubuntu sets up many shortcuts for casual use. For example, on Fedora, "service network start" is merely an alias for "/etc/rc.d/init.d/network start" and it only sets up network interfaces. On the other hand, Ubuntu's "service networking start" and "/etc/rc.d/networking start" work differently and the latter even starts the NTP daemon. This is why my three home servers, central, firewall, and backup, run Fedora, but I installed Ubuntu to my laptop using VMWare.

One argument was which version of Fedora, FC13 which has been installed on all of my servers, or FC14, the latest as of the time of my development. It would make my life a little bit easier if I had chosen FC13 because of unity, but I could not resist the idea of "the newer, the better." The TV recording server will not have an OS upgrade once it is installed during its hardware life time, so its OS version will diverge from other installations anyway.

I must confess that FC14 was a bad choice and I suffered a long delay from it buggy PC card reader package. It cost me nearly 2 months and $60 to figure out the defective PC card reader package and to start using the new digital recording system. If you are to build a new system avoid FC14, use other versions.

Another caveat with the Fedora distro is its short support spans. The fedora project mentions its goal is to introduce as much up-to-date stuff in a timely manner as possible and to release new versions every 6 months and an older version will lose update support in 1 year or after it successor is released. This is a bit too short for a practical server applications like mine. I heard CentOS is very compatible with Fedora with much longer support spans, so I may choose CentOS next time.

Software modules

The digital recording software roughly consists of the following components:

1. Recording scheduling front-end (GUI)
2. PT2 tuner card device driver
3. TV recording executive
4. ARIB25 decoder
5. TS (transport stream) splitter
6. Transcoding engine
7. File transfer
8. Recoded program file management
9. Media server

Development strategy

I have been developing and maintaining my home IT systems for years. This TV recording system is one of those and a private (i.e. non-commercial) project. Probably like many other home systems, I was not paying much attention to maintainability of my development. Most changes were made on ad-hoc basis, and I only used RCS (revision control system) in each individual directory for maintaining file change history. Recently, I have changed my strategy and started using more systematic approach for tracking my development because my home system is now distributed to three servers after upgrading both hardware and software platforms.

VMware

Fedora 14 on VMware – How to Install VMware Tools on Fedora 14

Using Shared Folders

Note: You can use shared folders to share any type of file. However, Windows shortcuts and Linux symbolic links do not work correctly if you try to use them via shared folders.
Caution: Do not open a file in a shared folder from more than one application at a time. For example, you should not open the same file using an application on the host operating system and another application in the guest operating system. In some circumstances, doing so could cause data corruption in the file.