[mythtv-users] Idea for faster channel surfing

Brad Templeton brad+myth at templetons.com
Fri Dec 3 01:58:48 UTC 2004

On Thu, Dec 02, 2004 at 06:49:33PM -0600, Dan Littlejohn wrote:
> Noob question, but why is it necessary to have the buffer require a 2
> second start time?
> Why could it not just drop frames at a rate not easily noticed until
> the buffer was full?  That would solve the surfing problem in a
> simpler way.

I think you probably mean to add frames, or am I misunderstand what you
are saying?

It varies from tuner to tuner, but many of them wait quite a while before
they decide they have a lock, and if the driver does this there is nothing
you can do to get around it.   They all seem to do it, as I am sure you
have seen how long it takes digital cable and satellite boxes to change
the channel.  When you combine those with a DTV it's murder.

I presume the DVRs like to sit a second or so behind live as a safety
margin.  I have not seen what happens if you try not to have that safety
margin, but if you are suggesting that you start as close to live as you
possibly can, and then slowly slide back a second (by adding duplicate
frames here and there) that sounds possible, if complex.

I maintain that the right thing to do is to realize you no longer need
to channel surf.  But it is tempting sometimes to our idle minds, so most
people never get fully weaned off of it, and they long for the old type
analog experience which allowed instant channel change.   You could pull
off quick change with several tuners as noted.

Far more interesting is quick back and forth among a set of channels
and recordings.   If it's live channels, you need a tuner for each one,
but quick flick back and forth between a tuner and a recording is
fully possible.

The Tivo has a bit of this.  I find it to be highly useful.  Generally
what happens is this.  Two people are watching a show they wish to watch
together.   One of them needs to go do something -- answer the phone,
bathroom, whatever.  You want to instantly zip to playing a different
source -- usually a recording -- that only you want to watch while the
other person is occupied.  As they walk back into the room you want to
push a single button and you're back to what you were watching together.

Kinda like surfing to another channel during commercials.

What's being said here is that to pause is not the action you want
when only one person in the needs to pause.  Instead you want quick

I do this a lot and it works quite well.

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