[mythtv-users] Hauppage HD-PVR Driver, MythTV, or not enough grunt...

[John P Poet]

On Fri, Apr 2, 2010 at 9:07 PM, Troy Telford <ttelford.groups at gmail.com> wrote:
> It works great when it's hooked up to my MacBook Pro (Running OS X & Using EyeTV).  While somewhat cool, it's hard to record TV that's on while I'm not home, as I take the MacBook with me.
>
> So, I decided to set up MythTV on one of my Linux boxen.  I run Debian (sid), so the drivers that are pre-compiled are pretty current.  In fact, it required pretty much zero effort to get my HD-PVR driver installed & working (all I had to do was plug in the USB cable).  In fact, it made me nostalgic for the days where you have to fight to get anything to work in Linux...
>
> However, not all is well in Linuxville...  If I do a simple 'cat /dev/video0 > testvideo.mpeg", I get the exptected video stream. I then played it in VLC - and the result was gorgeous.  (Well, as gorgeous as you can expect from "ice road truckers"... but I digress...)
>
> When I use MythTV, I'm problems with the video stuttering - more or less on a 2-3 second cycle.  It runs, gets worse, stops, and continues.  It does appear that both cores on my MythTV box are getting 100% utilization - though I"m not sure if that's because the cores are actually getting used, or if it's just that I don't have "enough" CPU to both record and watch TV.  (Because playback of a recording _outside_ of MythTV seems to work great).
>
> Since MythTV is new to me, I just wanted to see if MythTV normally used up 100% of the CPU, whether it needs it or not (I've seen programs like that), or if it's just that I don't have enough "grunt" (or in other words, enough CPU, given I'm running 1080p video and have a Core2 Duo @ 2GHz.)

The HD-PVR does not generate 1080p, best it will do is 720p or 1080i.

With a 2GHz Core2, you *might* be able to playback an HD-PVR recording
if you turn off the deinterlacing, but image quality will suffer (on
1080i material).  Myth 0.23 uses a newer H.264 decoder than Myth 0.22
did, and is reported to be 10% more efficient.  If you have not
upgraded to 0.23RC2, you might want to give it a try.

You don't mention what bitrate you are recording at.  You could try
lowering the bitrate and see if that helps, but it will also lower
image quality.

Personally, I would not even try to watch high-bitrate HD-PVR material
with anything less than a 2.8GHz Core2.  However, you can get away
with a pretty weak CPU, if you use VDPAU.  The HD-PVR produces
single-sliced H.264, so it does not benefit from multiple cores, and
instead needs a beefy CPU (or VDPAU) to decode it.

Given that you can buy a nVidia GT220 based card for as little as $40,
that is the route I would recommend.  The GT220 based cards will do
VDPAU with nVidia best deinterlacer, and handle the highest bitrate
HD-PVR material with ease.


John
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