[mythtv-users] HD Choppy or Jerky

[Dick Steffens]

I have an HDHomeRun Prime. I can successfully view standard definition 
channels from Comcast with it. But when I try to view HD channels the 
video is occasionally choppy or jerky, and the audio is out of sync. I 
can play back some HD content. I downloaded the HD version of Big Buck 
Bunny, and also have an HD episode of a TV show I recorded using my old 
HDHomeRun, the one with two antenna connectors on the back. In both of 
those cases the video is rock solid and the sound is in sync throughout 
the recordings. It's not consistent or predictable, but I usually get 
some picture breakup and also sound drop outs with VLC Media Player 
tuning an HD station. (I didn't use MythTV to do these later recordings. 
I just used the command line tools that are available for the HDHomeRun 
Prime.)

The hardware consists of a Lenovo ThinkCentre M58P, specifically a 
7483AEU, 2GB RAM, Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz, 320 GB 
hard drive, and an eVGA (nVidia) GeForce GT-610 video card, feeding a 
Panasonic TC-42PX14.T Plasma TV. The house network is a Linksys WRT54G 
router, CAT-5 cable, and 10/100 Ethernet. I don't use the wireless side 
of the router.

At this point I'm not convinced the GeForce GT-610 is up to the task. I 
consulted:
      http://www.mythtv.org/wiki/Choosing_Frontend_Hardware
but found that where it says, "anything nVidia 8-series or better," it 
refers to products nVidia considers Previous Generation Products. See: 
http://www.nvidia.com/object/geforce_family.html

On that page, the 610 is listed under a column heading that says, 
"Supercharged performance for your HD videos and photos, immersive 3D 
movies, and entry level gaming." Based on that I would expect the 610 to 
be able to handle HD video. However, I've heard that the 610 might be 
marginal.

I've also had hints that some versions of VLC Media Player introduce 
problems. The version I have is the one Ubuntu 12.04 includes, which is 
2.0.8.

So, I'm hoping the collected wisdom on this list can offer some 
recommendations on how to figure out my choppy video/out of sync audio.

My eventual plan is to install MythTV on this box. But I have a couple 
of other MythTV related issues, which I'll bring up in separate threads.

Thanks for any advice.


-- 
Regards,
Dick Steffens