[mythtv] Simultaneous Recording/Viewing (Two Tuners)
bjm at lvcm.com
Tue Jan 21 18:49:00 EST 2003
Risto Treksler wrote:
> Two tuner cards raise many interesting questions/possibilities
Isaac implemented this and it is already working ;-)...
> 1)record and watch @ the same time
> -how much power is needed to pull that off??
> so that you can still have a ringbuffer and to pause live tv with one card
> while the other is recording something
This works. You probably need to scale back your resolution
for 2 tuners on a CPU under 2GHz. I use 2 @ 352x480 on 1.2GHz.
Isaac can almost get 2 @ 640x480 with an Athlon 1800+
> 2)multiple ringbuffers ?!
> -watch a movie on some channel on one tuner card, press pause
> -switch to different tuner card, and watch the hockey game for a minute
> with instant replay capabilities
> (the 2nd tuner would have its own ringbuffer)
> -switch back to the tuner with the movie and press "play"
Both tuners have ring buffers for live recording. However,
if I flop back and forth, I record both then watch from the
> 2a)this way the current AND the previous channel would always
> have a ringbuffer going so you can rewind a little to see what you missed.
> (unless of course one tuner is recording something)
> recording conflict resolution would also be affected by multiple tuners
> -option to limit # of tuners available to for recording (1, 2, all)
> so you can make sure one tuner free for viewing live tv
> -only report a recording conflict if no tuners are available to record.
It does report if no tuners are available and gives you the
option of watching in progress.
> 3)seamless switching between tuner cards?
> -same as above, but it might be nice if after pausing the movie
> changing the channel would automagically chacge you to the second tuner
> and changing back to the movie
> would automagically switch you back to the first tuner
> -everytime you change a channel, you switch tuners,
> so that the previous channel always has a ringbuffer going,
> unless one ore more tuners are paused
The viewer doesn't need to know which physical card is
being used, only that the channels that are being recorded
(timeshifted). There is also picture in picture so
you can see both. Still, if you want to keep things it is
best to record them.
> how much of this is implemented?
> how much processing power/RAM/hard disk speed is needed to record 2 or even 3
> or 4 shows at once?
About 1GHz per tuner plus one or two PCI slots. Putting a
bunch of tuners in one machine doesn't scale as well as
having multiple machines with tuners scheduled from one
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