: HDTV using MythTV


ethinder
2009-12-11, 08:17 PM
I am planning on doing HDTV using Myth TV. One backend and at least 2 frontends for now, expandable to 4 in future.

Can the experienced folks guide me on the hardware to choose for backend and frontends?

frontend does not need to have a DVD drive to play dvds; but just to play out on to HDTVs from backend, either live TV from ATT USERV(fiber optic cable service) or ripped recordings from backend. Also looking to have driveless, fanless CPU and graphics card , if possible.

backend needs to take cable HD output and feed to frontends, also analog TV, rip DVDs and BLURAY, and play them out.

What would be the best hardware choice that would work with MythTv today and also not being an overkill at the same time?

I have done Linux installations earlier so hoping that would not be a problem.

Also the Linux distribution that would allow exploring myth tv to its fullest in the backend, but not having all the other Linux OS features?


Maybe I am asking for too much, but please let me know how close we can come to this.

Thanks
Ethi

Wayne
2009-12-12, 04:24 PM
The thing to keep in mind is that this is primarily a Canadian forum and if you mention ATT USERV then you must be in the US. Am I correct in assuming that you get digital cable service from AT&T with a set top box?

What kind of TV channels do you want to capture - OTA or cable channels as well. If you want premium cable channels then you will need to use the Hauppauge HD-PVR as your capture device.

You might want to consider extenders rather than PCs as your frontends. I run SageTV as my HTPC software with Windows Home Server as the backend. I then use SageTV extenders as frontends. They are about 6"x6"x2" cost US$180 and have no fans. SageTV does run on Linux as well but it is not free. I don't know if there are extenders like this for Myth but they are much easier to maintian than PCs, cheaper and just work.

ericball
2010-02-01, 11:56 AM
As Wayne indicated, you will probably get better answers from dedicated MythTV forums where others AT&T customers hang out.

First, I'm going to assume there's a way to get from the fiber to QAM256 over coax (which is the standard for digital cableTV). That then can be connected to a MythTV compatible ATSC capture card (http://www.linuxtv.org/wiki/index.php/ATSC_Devices). (In particular the Air2PC/AirStar cards with onboard PID filtering.)

Second, you should determine what content is available in the clear. Typically this is only your local stations. So even if you subscribe to other channels, MythTV will not be able to decrypt them. The alternative is to dedicate a set-top box to MythTV and use a Hauppauge HD-PVR to re-encode the component outputs.

I just built a Mythbuntu backend and will be using my PS3 to watch the captured streams like a uPnP extender.

stampeder
2010-02-01, 12:54 PM
The MythTV Wiki is essential reading for understanding which hardware and broadcast sources are compatible:

http://wiki.mythtv.org/

mlord
2010-02-11, 12:04 AM
Dang. I've lost track of the original thread where Stampeder & I were discussing VDPAU capable cards for MythTV... (so feel free to move this post, but please leave a forwarding link behind).

Newegg.ca is now selling a fanless Zotac GT 240 card, with 1GB of DDR3, for under $100 or so. This looks like a worthy successor to the 1GB 9500GT currently in the MythTV box here, so I've ordered one.

The Advanced/2X (temporal/spatial) deinterlacing works fine on the the 9500GT, but using the Noise Reduction and/or Sharpening (on analog SD content) taxes that GPU, giving the odd stutter or two.

Thus the upgrade, from 32 shaders to 96 shaders (VDPAU uses the shaders for post processing like this), plus full hardware MPEG decoding (the 9500GT has only partial hardware decode).

I'll post more (somewhere here) once we've put the GT 240 through its paces here on the weekend.

Cheers

mlord
2010-02-12, 12:19 AM
Newegg.ca is now selling a fanless Zotac GT 240 card, with 1GB of DDR3
...
I'll post more (somewhere here) once we've put the GT 240 through its paces here on the weekend.
The UPS guy dropped off the fanless GT-240 card today. It is now in the MythTV box.

As anticipated, the passive heatsink was about 3/16" too tall for the Antec Fusion case. But a few minutes at the belt sander in the workshop cured that! ;)

Despite the now slightly smaller heatsink, the card runs 5-8 degrees C cooler than the fanless Sparkle 9500GT card it replaces, even though it has about 3X the horsepower (96 shader CPUs versus 32 on the 9500GT).

I've now turned on vdpauivtc (inverse telecine) for all playback, plus vdpausharpen=0.25 for analog playback, and am still experimenting with vdpaudenoise=nn for analog. The 9500GT would sometimes stutter with those, but not the new GT-240 card.

So far, things are looking good.

Cheers

mlord
2010-02-13, 02:07 AM
No question -- playback is noticeably smoother in many cases now, despite me never really having noticed the odd jerkiness before.

One downside: Unlike the 9500GT, the GT240 has full hardware MPEG2 decoding on-chip. And when it hits a noisy patch from an OTA HD capture, it kind of exagerates the pixelation. Much worse than the 50/50 decoder of the 9500GT, which in turn was less forgiving than a 100% software-only decode.

Fortunately, most of our captures are pretty much noise free here. And MythTV does offer the option of using 100% software decode in combination with VDPAU for the rest of the video chain.

Cheers

classicsat
2010-02-13, 11:38 AM
First, I'm going to assume there's a way to get from the fiber to QAM256 over coax

Uverse is a total IPTV service, like Telus and MTS. There is no QAM.

The only way to get HD from an IPTV box into a PC is with the Hauppauge HD-PVR box. For SD, any number of tuner/capture cards will work.