[mythtv-users] PVR Hardware

James O. Rose, III james at StubbornRoses.com
Thu May 5 23:01:12 UTC 2005


My delay fixation stems from trying to get CCTV working reasonably with 
PVR350s.  Even though Hauppauge advertised the suckers as real-time, they 
weren't (with windows or Linux).  Strange since the conextant chip spec sheet 
shows they can be real-time.  I suppose I should let this go.  I was thinking 
this would be really, really annoying for channel surfing, but I forgot to 
consider that you use the guide for that now =)

regarding cost on minipcs, I was considering a used 800-1000 MHz Pentium/AMD 
or Celery in a SFF case,  not necessarily a new via epia.  

Agreed it would suck if I lost my network, but if that happens then doesn't 
the whole frontend go to heck anyhow?  I was still planning on leaving the 
RG59 cable connected to the TV for backup...

Does see any benefit to going to GigE?  Myself, I've sent 4 MPEG2 streams at 
once over 100baseT and SMB w/o any noticable delay for storage, but live 
viewing might be another story.  I was really considering doing this anyhow 
just to make my NFS/SMBed home directories faster.

Will take your (and everone elses) advice and go the ivtv route and stop 
worrying about the delay I guess.

Regarding XBOX/PC, the comments seem divided, may just go with a PC so I don't 
have to deal with all of the modding, and strange distros.

Thanks for all the advice,

James

On Thursday 05 May 2005 05:13 pm, Gavin Haslett wrote:
> Maybe I'm sort of missing the point here, but why so stressed about the
> delay from live TV? Honestly, my wife and kids use my Myth box and the only
> time they even notice the delay (that they've mentioned) is when changing
> channels. This causes a 3 second delay or thereabouts while live TV is
> cached before the channel "changes". Of course, I know the channel has
> already changed... but that's a detail you live with on any PVR, be it
> Myth, TIVO or any of the "pretenders to the throne". My wife and kids seem
> quite happy to deal with the slight delay for the sake of pausing and
> rewinding live TV.
>
> My setup is a satellite box attached to my Mythbox through an S-Video
> connection for video input to a PVR-250 card. Channel changing is done
> through a serial cable to the back of the satellite box. I use the guide
> built into Myth now instead of the one on the satellite box... in fact
> everything's done through Myth now so I find the delay is such a non-issue.
>
> Catpure Cards: BTTV *might* result in slightly less delay on live TV if you
> recode Myth to override the 3 second built-in delay. May or may not be
> worth it as in the event your machine gets pegged on the CPU or you have a
> glitch on your disk subsystem, you're more likely to get a glitch in your
> TV viewing. Not perfect. Also, BTTV just sends raw frames down the PCI
> bus... which dependent upon other cards in your system may actually
> saturate the PCI bus during high traffic loads. The advantage of capture
> cards like the Hauppauge is that they send only MPEG2 data (pre-compressed)
> down the PCI bus, therefore saving data bandwidth. My first ever Myth-type
> box used a BTTV card... it sucked because (as I later ascertained) I had a
> badly behaved bus-mastering gigabit Ethernet NIC in another slot that was
> causing latency to other cards on the bus. Now I use a PVR-250 and have
> been very happy with the results. I do have some apparent traffic problems,
> but I attribute them more to my disk subsystem which is rather slow than I
> do the card. 3 BTTV cards on the same bus might be a problem... I'd get
> onto doing some mathematics on raw frame speeds down the PCI bus.
>
> Basically, as far as the frontend, you can get your technical requirements
> (fanless, quiet, flash hard disk), but not for less than $200! Even fanless
> and quiet with a hard drive is going to cost you more than that
> realistically. Be realistic about your requirements. Myself, my frontend is
> also my backend... but when I get around to doing a dedicated frontend I'm
> going to spend a few more bucks and get quality and quiet hardware.
>
> Hmm... for a frontend you perhaps might want to consider a modified XBox
> (chintzy solution IMO), or a fanless machine using PXE boot to your
> backend. Works great, but boy, if you lose your network connection...
>
>
> 	-----Original Message-----
> 	From: mythtv-users-bounces at mythtv.org on behalf of James Rose
> 	Sent: Thu 5/5/2005 3:35 PM
> 	To: mythtv-users at mythtv.org
> 	Cc:
> 	Subject: [mythtv-users] PVR Hardware
>
>
>
> 	This may have been answered many times already, but searching the lists
> 	(and google) didn't seem to help too much.
>
> 	I'm wanting to build a distributed myth setup (ie one mythbackend and two
> 	mythfrontends), and I'm wondering:
>
> 	1) What is the best recording card to use?  I've got lots of experience
> 	with Hauppauge PVR-350s (I built a 4 channel recorder..w/o myth), but I
> 	find the delay completely unacceptable for live tv.  I haven't played with
> 	IVTV since version 1.9, so maybe this is fixed (seems to be a hardware
> 	issue though).  Acceptable delay to me is <1 second.  I'm willing to trade
> 	quality for speed here since I'm recording analog cable to begin with.  My
> 	only other requirement is that it does hardware recording, since this box
> 	is also my web/mail server (machine is a 2.8GHZ AMD with 1GB RAM, and
> 	400GB IDE with RAID6/LVM on Debian Sarge). In addition, I plan on having 3
> 	recording cards in the box.  Are the BTTV devices in general faster than
> 	IVTV?  Can all this even be accomplished at this point in time?
>
> 	2) What's the best compromise for mythfronend systems.  I've read a lot of
> 	mixed reviews on using xboxes/ps2s.  I'm wanting something really cheap
> 	(around $200/box), and extremely quiet.  I'd like fanless, and may skip
> 	the hard drive and go with flash memory.
>
> 	MTIA,
>
> 	James
>
> 	_______________________________________________
> 	mythtv-users mailing list
> 	mythtv-users at mythtv.org
> 	http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users


More information about the mythtv-users mailing list