[mythtv-users] MythTV vs. Windows Media Center

[Raymond Wagner]

On 2/10/2011 16:23, Reynolds, Brian wrote:
> OK... I'm bottom-posting even though I think it's much easier to read
> the other way around because I don't have to scroll all the way to the
> bottom...

Top posting only makes sense if you are responding to a specific 
question, to a specific person, and it was recent enough that they don't 
need any context.  For the vast majority of communication, bottom 
responding makes more sense.

http://idallen.com/topposting.html

> In response to your post about FireWire control of an STB... OK, then
> channel changes are a breeze.  How do I accomplish controlling the menus
> in the VOD content?

This simply won't work due to some low level design choices made early 
on with MythTV.  MythTV is designed to record to record straight to 
disk, and allow the frontend to play from the on-disk file.  To prevent 
the frontend from hitting the end of the written file, the frontend is 
never allowed closer than roughly two seconds behind the live 
recording.  Now you could spend a lot of time rejiggering this.  Force 
the frontend to stream from the backend, allow multiple users on a 
single recording ring buffer on the backend, have more frequent 
broadcasts of file information to the frontend, and you might get the 
required latency down to under half a second for reliable operation.  
Even then hardware encoders used for analog capture are still going to 
introduce a second of latency of their own.

If you've ever tried to use something interactively over a high latency 
link, you'll understand that even a few hundred milliseconds is 
painful.  The couple seconds MythTV would introduce would be unusable.  
It honestly wouldn't take more than an hour or two for someone 
experienced with LIRC to write a program that listens on lircd, sends 
commands to a remote system, and blasts them to a cable box.  The lack 
of any such systems available for use seems to indicate anyone who has 
attempted it has found it not worth the effort.