[vdr] addign STB-style timeshifting to VDR

[Lauri Pesonen <lauri.pesonen@firsthop.com>]

Hi list,

I'm interested in implementing STB-like timeshifting features to VDR. 
What I have in mind is two features:

* pausing live TV (and resuming it later on)
* configurable length instant replay (I.e. watch the last 10 seconds again)

I've being going through the VDR source now and then and I have a faint 
idea how to do this. What I don't know is how the features should work 
on a more detailed level. I have no experience with STBs that have these 
features, so I don't know how these features should work.

A few questions:

1. If you pause live TV
	- will the pause mode quit at some point, e.g. after 10 mins?
	- is the stream recorded permanently (can replay the stuff later 	on) or is 
the recording lost after watching it?
	- can you move forwards and backwards while watching a
	timeshifted show?
	- What happens when you catch up with the live braodcast, e.g. 	
	by fast forwarding commercials? You should switch back to live
	tv, but do you notice it?
	- The will have to be written to disk...?

2. Instant replay
	- do STBs have such a feature?
	- how long is the replay, e.g. 10 secs, 15secs?
	- since pressing the instant replay button is a basically the
	same thing as pressing the pause button, should the data
	buffered for the instant replay be saved to the beginning of the
	recording?

3. VDR buttons
	- should I introduce new buttons to VDR as a whole?
	- which ones of the old buttons couls I use (pause and rev are
	out of the question since they are already in use in transfer
	mode)

All suggestions and tips are highly appreciated!

Br, Lauri

P.S. This will probably take a while since I haven't got that much time 
on my hands, I haven't implemented anything in C++ for a while and the 
design needs to be thought out first. So hold your horses.