[mythtv-users] question involving multiple frontends

Adam Stylinski kungfujesus06 at gmail.com
Mon Feb 9 21:50:34 UTC 2009

Michael T. Dean wrote:
> On 02/09/2009 03:54 PM, Adam Stylinski wrote:
>> Adam Stylinski wrote:
>>> While I'm glad that there is a way to do this manually and was looking
>>> for a method similar to this, my main concern is having duplicate
>>> recordings.  In a house with multiple backends, it is hard to know when
>>> the user is watching what, and there will be overlap if it attention
>>> isn't paid (again, causing duplicate recordings
> Which aren't a problem because Myth can handle it and LiveTV is
> autoexpired with prejudice.
>>>  and wasting a tuner).
> Which means if you have people watching LiveTV and you're concerned
> about running out of capture cards/tuners, you need more.
> Simple formula:  1 capture card per simultaneous LiveTV user + 1
> capture card per desired scheduled recording or 1 capture card per
> channel (multiplex, if using multirec), whichever is smaller.
> And, I'll guarantee that the $50 per each additional capture card you
> buy is /significantly/ cheaper than the cost of the code required to
> do it your way.  (And, since Waste-Your-LifeTV, er, LiveTV, is not
> something that interests many MythTV users (especially developers),
> finding someone to contribute all the required hours of their time to
> write and test (and--I would hope--maintain) the code will likely be a
> challenge.)
>>> What might be great, although likely impossible, is for the frontend to
>>> look for livetv sessions already in progress and stream from them. 
>>> Then
>>> if the user switches channels on one frontend, their frontend simply
>>> goes to another tuner if there is another user watching the channel
>>> that
>>> is being changed (sorry if my English wasn't clear there).  So
>>> essentially a situation would occur like so, viewer A is watching WCPO,
>>> viewer B is watching WCPO also.  User A wants to switch to WKRC.  User
>>> A's frontend accesses another tuner on the backend as to not interrupt
>>> the livetv session of the other user, and user B watches seamlessly,
>>> never stopping the recording livetv program in progress.  I can see
>>> this
>>> being useful for other reasons, i.e. not wasting a tuner for potential
>>> scheduling. 
>> Also, I may not have been clear on this, but I mean automagically find
>> existing livetv sessions on the same channel when the user goes to
>> "watch tv".  What you said isn't the same, although it is useful, again,
>> if you're aware of what user B is watching.
> So, you start LiveTV on frontend A.  Someone else start LiveTV on
> frontend B.  Then 2 scheduled recording begin, and now all 3 of your
> capture cards are busy recording different things.  Then, the person
> watching LiveTV on frontend B decides that the show is boring and
> changes channels to a channel that's not being recorded for either of
> the 2 scheduled recordings.  What should Myth do?  We could pop up a
> dialog saying, "Sorry, but due to your bad timing at starting
> LiveTV/changing the channel, you're stuck watching something that
> another user is watching or that I'm currently recording."
> Now, let's make it more complex.  Let's say the person watching LiveTV
> on frontend B actually loves the show, but you decide it's drivel, so
> you try to change the channel, but all capture cards are in use.  What
> does Myth do here?  Well, since you started LiveTV first, let's say
> Myth decides you have priority/control.  Now, the person who was
> watching a very enjoyable show gets hopped to a different channel.
> OK, so let's say Myth decides that just because you started LiveTV,
> that doesn't mean you should have priority.  Instead, it figures,
> since both you and frontend-B-user were watching the same show when
> all other capture cards became busy, whoever decides to change the
> channel isn't allowed to do so (i.e. you both have to watch the same
> show).  So, you get a pop up dialog saying, "Sorry, all capture cards
> are busy, so you're stuck watching this drivel."  Now, the user
> watching LiveTV on frontend B thinks, "You know, this show really
> isn't that well-written, let me see what else is on..."  Now that user
> tries to change the channel (perhaps even to the same channel you had
> tried to change to) and gets a pop up saying all capture cards are
> busy.  So, the user watching LiveTV on frontend B yells upstairs to
> you, "Hey, you really interested in that show?  It's garbage."  You
> answer, "No joke, let's switch."  Then--coordinating by yelling to
> each other--you both exit LiveTV (making a capture card available),
> then one of you enters LiveTV and the other rejoins the LiveTV
> session.  But what you didn't realize is that frontend-B-user snuck
> into LiveTV /before/ you restarted it and started watching the /only/
> show you've ever seen that was worse than the one you were just
> watching.  Pretty soon, you have to walk downstairs, steal the remote,
> exit LiveTV, and go back up to your frontend of choice to watch your
> LiveTV program of choice.  (Then frontend B user retaliates with
> remotely launched Nerf missiles, until soon enough, the UN (that is
> "UNhappy family members") send in peace-keeping forces who decide that
> everyone has to watch a completely different show.)
> All this violence could have been avoided if only you had enough
> capture cards.
> Basically, the problem is that with this approach, we can't guarantee
> the user a capture card, so a LiveTV user may get stuck.  The /only/
> way to guarantee that people can watch what they want is to either a)
> schedule the use of the capture cards--i.e. don't use LiveTV or b)
> have enough capture cards for LiveTV /plus/ all scheduled recordings.
> But, if you'd like to, feel free to add the idea to
> http://www.mythtv.org/wiki/Feature_Wishlist .
> Mike
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I definitely see what you mean, the hopping to another tuner wouldn't
exactly work if there were no more tuners available.  I do watch OTA,
where there isn't as much selection, but I can see where this might
apply to somebody tuning into ClearQAM or analog cable.  I don't mind
spending an extra 120$ on another PCHDTV card, however, I'm out of PCI
slots on the main backend, and slave backends would have to be hooked up
to secondary antennas (splitting the outdoor antenna more than the three
tuners I'm about to do it among may become quite a hassle, even with a
powered splitter).  It could mean buying one of those smaller
omni-directional outdoor antennas, or it could mean biting the bullet
with the poor reception of the standard rabbit ears.  Hmm, more to come.

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