[mythtv-users] MythTV 0.26 records live TV without being told to do so

Ronald Frazier ron at ronfrazier.net
Thu Jan 10 04:37:13 UTC 2013


On Wed, Jan 9, 2013 at 10:38 PM, Malte Gell <malte.gell at gmail.com> wrote:
> Am 10.01.2013 04:27, schrieb Michael Watson:
>
>> MythTV is a DVR/HTPC
>> Kaffeine is a Media Player
>
> Hm, to me this is odd. When I build a HTPC and want to watch TV, I only
> want to watch TV and don´t want to record. If I want to record I want to
> tell it explicitly to the software. When I watch TV for some hours or
> listen to DVB music stream my harddrive gets filled, to me this is not
> okay, but, well...

You are thinking a bit narrow minded about how you and others might
want to use a DVR.

Contrary to what a few others have said in this post, myth did NOT
always behave the way it currently does. Years ago (I want to say up
until around version 0.18 or so, but don't feel like looking it up),
mythtv used a ringbuffer, much the same way TiVo does (or at least
did...not sure what they do now). That's great in that it uses very
little hard drive space, but the downside is that it limits your
potential to intermingle/blur the line between LiveTV and DVR
functionality. With a ring buffer, you limit the amount of time you
can pause TV.  You might only get an hour or so out of your buffer,
and if you are away longer than that, too bad. Now that might seem
fine, but I can't tell you the number of times (especially now that
I'm a dad) that I've paused LiveTV for 2-3 hours before I FINALLY get
back to it. Or how about when you watch a movie, and when you get to
the end say "ahah" because something that happened at the beginning
now makes more sense, and you want to go back and rewatch it. That's
not gonna happen if it was longer ago than your ringbuffer. Now, you
might say you could avoid this by bumping up the size of your ring
buffer to hold 2-3 (or more) hours of TV. However, you've now
dedicated that amount of space to live TV. If you want to do that, you
might as well just make a 20GB partition and let the current system
store its live TV there.

Another limitation of the ringbuffer is that it prevents you from
saving a live program after you've started watching it. Have you ever
watched a movie or documentary, and then halfway through said "I'd
like to watch this again" or "I bet <person X> would like to see
this". Well, with the current system, you just toggle it to record and
you are done. With a ringbuffer, this isn't really possible without
adding a LOT of complexity to the code, and even then it would only
work in some circumstances.

Another issue is that you need separate ring buffers for each live
stream you might play. Have 2 frontends? Now you need 2 ringbuffers.
Oops, don't forget about picture-in-picture...better make that 4 ring
buffers. In short, you'll end up dedicating a HUGE chuck of disk space
just for ringbuffer space you may never use. You're better off with
the current system and telling it to only keep live tv for 1 day.

I'm sure I can think of other issues too, but the gist of it is, the
current system added a lot of functionality that was missing back when
ringbuffers were used.

-- 
Ron Frazier


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