[mythtvnz] DVB multicasting

[Tortise]

----- Original Message ----- 
From: "Nick Rout" <nick.rout at gmail.com>
To: "MythTV in NZ" <mythtvnz at lists.linuxnut.co.nz>
Sent: Tuesday, October 27, 2009 10:03 PM
Subject: Re: [mythtvnz] DVB multicasting

There is no provision for synchronised viewing. However if we all want
to watch top gear live then you set it to record on the backend. Any
numbber of frontends can watch that recording, live or within a few
seconds of live. (Why you would want to, and have to sit thru the ads
is another point)

=> Apologies Nick for not being clear, I agree I have no issue with Live TV, it can be watched....live!   I was really referring to 
simultaneous synchronised multicast playback of recordings, +/- commercial deletions.

(Have tried re-enabling the "<", the Gates derived ware will not add them back in! Perhaps a reboot will re-enable it in due 
course!)



> Two (or more) frontends can watch the same recording at once.
> They won't be synched, but they won't be under multicast either
> (becasue different systems will have different inherent delays).
>
> ============================
> "Inherent delays" and "won't be synched" wrt multicast??? we'd be talking millisecond delays here, I'd not see that as a concern.
> How would that be a concern?
>

I send a signal out multicast. To all intents and purposes each system
on my lan gets it simultaneously. However each machine has different
hardware. There could easily be a delay that is annoying, in that
there will be an "echo" in the sound. A few milliseconds can be
enough.

=> I agree this might be an issue if those different pc speakers were in the same room, but then depending where one sat it would be 
an issue anyway.  Would it be an issue for echo between rooms?  The volume in another room would need to be high enough to be heard 
in the adjacent room.  Is that the potential echo you are referring to Nick, I'd not see that as a concern.  (Or are you suggesting 
an echo is returned over ethernet?  Not to my expectation using multicast udp.)

Given we have not done the proposed multicast synchronisation it seems the echo problem is derived in no more than informed 
prediction.  What is the echo path you predict?

> You can try it now with the OP's setup suggestion. Let us know the result.

I'm interested.  What's the "OP setup suggestion"?