[mythtv-users] Way out idea on watching same thing in multiple rooms

Greg Oliver oliver.greg at gmail.com
Mon Jan 4 23:23:20 UTC 2010


On Mon, Jan 4, 2010 at 4:38 PM, Eric Sharkey <eric at lisaneric.org> wrote:
> On Mon, Jan 4, 2010 at 5:20 PM, Matt Emmott <memmott at gmail.com> wrote:
>> I have Charter Cable. When I first hooked up my TV and scanned for QAM
>> channels, I picked up a ton of blank channels. I'd occasionally see if
>> anything was on these channels and eventually realized that these were
>> 'open' channels for On Demand. I couldn't choose what show I was watching,
>> but if somebody else had rented, say, Cars, I could tune in to their session
>> for free. Eventually Charter encrypted these channels, but it was neat at
>> the time.
>>
>> The reason I'm bringing this up is, when whomever bought this content would
>> pause, rewind or fast forward, I was there with them. I can't say if I ever
>> lost sync with exactly what they were seeing, but I can say that the
>> experience was the equivalent of having my own feed off a splitter behind
>> their STB. So if it's possible over Cable TV Coax, I gotta think there's a
>> relatively easy way (in theory) to do the same with IPTV.
>
> I think people are underestimating the degree of precision required
> for a whole house jukebox type scenario.
>
> If you're watching your neighbor's PPV, you wouldn't have had any way
> of knowing if you were seeing it 500ms ahead or behind him.  If you
> want a whole-house jukebox, 500ms is an eternity.
>
> Your best bet for something like this is really very long HDMI cables
> or something like it, with all output generated from a single host.
>
> I have speakers in multiple rooms connected to a stereo fed by my
> mythTV so that I can run mythmusic and get the whole house effect.
> Distribution is done with ordinary speaker wire.  I haven't tried
> distributing video, though.
>

My company uses ffmpeg's ffserver to do this everyday.  Like it has
been stated though, there will still be latency and there is
technically no way to achieve perfect sync due to differing devices
(even with perfect timing on a PC).  You would need broadcast quality
equipment to pull it off.  Multicast is your closest bet for a PC
network though.

Even with long hdmi cables or speaker wires, you are still adding
latency just like ethernet would have - albeit at differing speeds..
If your TVs are not within earshot, you would not notice it though -
unless the speeds of your frontends vary greatly, then there is yet
again more latency.

-Greg


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