[mythtv-users] Time to take the next step...

VCRAddict MythTV_01 at appropriate-tech.net
Mon Nov 17 21:13:08 UTC 2008


At 12:10 PM 11/17/08 -0800, Yeechang Lee wrote:
 >
    [snip]
 > 
 > His message was somewhat ambiguous, but I disagree on the proper
 > reading. From
 > (<URL:http://www.gossamer-threads.com/lists/mythtv/users/357580#357580>):
 > 
 > > I think you need more processor power for ATSC system. I have a
 > > frontend only with a 2.4GHz P4 and it is not quite fast enough even
 > > running XvMC (which you do not want to run). My FE/BE runs a 5400+
 > > and it is fine.
 > 
 > Given how he talks about how his 2.4GHz Pentium 4 frontend is
 > inadequate "for ATSC" (which in the US is more or less syononymous
 > with "high definition"), he was (as I read it) referring to your
 > expectation that a 1.6GHz Pentium 4 would be sufficient as a HD
 > frontend. Allen, can you clear this up for us?

If indeed that's what he meant, I suppose I now understand your
interpretation.  But given that from its inception the thread is/was
focused upon my impending Back-End-Only build -- which, at least for now is
the ONLY part of my MythTV system destined to have any ATSC tuners in it
(or logically attached to it, in the case of the HDHomeRun approach) -- and
was started for the purpose of seeking advice on that project, I took his
otherwise unqualified statement about needing "more processor power for
ATSC system" as intended to apply in *that* context.

 > > As for whether or not the existing FE will prove adequate for playback of
 > > the stuff the new Back-End captures... that remains to be seen; but I
 > > suspect that I'll *have* to use XvMC for it to work acceptably.
 > 
 > Again, your 1.6GHz Pentium 4 frontend just isn't going to work today
 > for native HD playback, with or without XvMC.

Well...  I guess we'll find out; for there's no way I'm going to muck about
with or replace that FE/BE system until the new BE box is finished, up, and
running.  Just too much on my plate to tackle both projects at once.

That said, can you offer any suggestions for how to make that combination
work (if only temporarily, while a new/upgraded FE box is built), if it
turns out you are right about the 720p/1080i playback?  I'm thinking here
of things like the various "recording profiles" and such, or perhaps having
the Back-End automatically transcode the recordings into something easier
for the FE/BE system to "swallow".  This is an area of MythTV functionality
that I have not (as yet) delved into at all, simply because I have not
needed to.  But the question will remain relevant even if I eventually
replace that FE/BE system for High-Def playback; for if that happens, then
the old FE/BE would be moved (more-or-less intact) to the Master Bedroom,
where it will drive a conventional 27-inch NTSC/4:3 CRT-based TV.

 > > Now it seems to be you who is contradicting himself.
 > > 
 > > As noted several times so far in this thread, "recording ATSC streams" is
 > > *all* this box is destined to do.
 > 
 > No contradiction. Same misunderstanding as earlier, in which Allen was
 > (as was I) referring to your 1.6GHz current frontend/backend and I
 > followed suit. I took "host system" in your first quote above to mean
 > the same 1.6GHz system, and for your overall statement to mean that
 > you believed that offloading the backend functionality from it would
 > provide enough horsepower to play HD. We were speaking about apples
 > and oranges, it turns out.

OK.  So now that we are (hopefully) on the same page, do you agree that the
proposed donor system -- to review, it's an Asus A7N8X-E Deluxe mobo w/ AMD
Athlon XP 3000+ (2.167 GHz actual clock rate) CPU and 1GB DDR RAM -- *will*
be more than adequate for my proposed usage... namely, as a dedicated
Back-End-Only system with up to 4-6 ATSC tuners (but NO NTSC tuners)
installed/attached..?

 > To clarify, my point was that removing the backend functionality from
 > the 1.6GHz box would help relieve memory usage more (much more,
 > depending on how big your database gets) than CPU usage (it'll help
 > some, not a lot).

I'm not really planning to "remov[e] the backend functionality" from the
existing FE/BE system, at least not immediately.  It would remain a
combination FE/BE system and remain responsible for running the GUI (I'm
not sure what that implies WRT maintaining the recordings database, which
itself would be spread over both systems).  It will also remain responsible
for recording all the NTSC stuff, since that's where the NTSC tuners are
(where at least one of them will remain more-or-less indefinitely, if for
no other reason than to provide an interface for the IR remote).  At least
most of this will remain true if/when that box moves to the bedroom.



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