[vdr] Re: addign STB-style timeshifting to VDR

[Emil Naepflein <Emil.Naepflein@philosys.de>]

> 
> 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)

Good idea! But you probably opened pandoras box. ;-)
Everything below are ideas that would be nice.

> 
> 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?

There should be some user selectable time (preselected in setup). This
also depends on the available disk space.

> 	- is the stream recorded permanently (can replay the stuff later 	on) or is 
> the recording lost after watching it?

There should be an option to store it as permanent recording. The
recording itself should run permanently on the currently selected
channel. If I switch channel there should be an option to continue
recording probably with a selection when the recording should be
terminated. On the new channel the permanent recording should start
again if a card is free of course. The priority of this permanent
recording should be selectable just like for other recordings. So when a
timer fires it may interrupt the permanent recording or not depending on
the priority. May be permanent recordings can be setup just like timers
with all the important parameters and kind of moving start and endtimer.

> 	- can you move forwards and backwards while watching a
> 	timeshifted show?

Yes.

> 	- 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?

When activating this mode you should always view the recording and not
live. Passing past the end isn't possible. Only when stopping this mode
or switching to a different channel you go into live mode. Switching
channel is effectively a pause for the current channel. 

> 	- The will have to be written to disk...?

Yes, this will allow to keep the recording.

> 
> 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?

Instant replay could be implemented just like the Pausing. The only
difference would be the amount of time you go back.

> 
> 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)

The buttons should be usable just like in play mode. May be you must use
one of the color keys to activate the pause mode from live mode.

> 
> All suggestions and tips are highly appreciated!

I hope I didn't overwhelm you with ideas. ;-)
The most important thing for this is that it is easy to use.

Emil