Home Theatre computer

[geoffrey mendelson]

On Nov 9, 2009, at 10:36 PM, Noam Rathaus wrote:
>
> There are US solutions that are non-Apple to do what I am looking  
> for, but I
> can't find them in Israel.


Apple bases their operating system on BSD and it is open source. Their  
GUI is not, but there is a decent port of X Windows, and a user  
community supported upgrade to the Apple base product. Open source  
software works very well on it and there a lots of things ported to it.

To answer another posting, there will always be a delay switching  
channels on a digitial TV system. While analog TV sent a new frame  
every 1/25 of a second, digital TV uses the key frame concept. Every  
once in a while an entire frame is sent, the rest of the time, the  
frames are sent as the difference between the current frame and the  
previous one. So you won't get a picture until the next key frame is  
received and decoded.

How often a key frame is sent depends upon the boradcaster. Israel  
digitial TV is an attempt at squeezing the most you can get out of a  
single signal, so the key frames are sent less frequently. I've never  
timed it, but it seems like a long time.

The other problelm is a design feature of MythTv. In order to make  
live pause and backup work, MythTv always records what you are  
watching. The video you see is a playback of the recorded video.  
Depending upon the compression you use to record and the speed of your  
processors, the delay can be 2-3 seconds (or more).

Geoff.
-- 
geoffrey mendelson N3OWJ/4X1GM
Jerusalem Israel geoffreymendelson at gmail.com