[mythtv-users] Bitrate/quality on PVR-150

[Chris Porter]

On Wednesday 13 August 2008 03:36:58 am Scott Traurig wrote:
> > Date: Tue, 12 Aug 2008 19:14:46 -0700
> > From: Brad DerManouelian <myth at dermanouelian.com>
> >
> > On Aug 12, 2008, at 6:23 PM, Scott Traurig wrote:
> >>> Date: Tue, 12 Aug 2008 09:32:35 -0500
> >>> From: jedi <jedi at mishnet.org>
> >>>
> >>> ...place the blame where it really belongs: with your cable
> >>> operator.
> >>
> >> Not at all! The thread has taken some interesting twists and turns
> >> during
> >> the day, but getting back to comparing apples to apples...
> >>
> >> If I use my Pioneer DVR to record off the same composite output of
> >> my STB
> >> that is the input to my Myth box the resulting quality is
> >> substantially
> >> better on the Pioneer. I have a dual tuner setup with a 150 and a
> >> 250. They
> >> both look equally bad compared to the Pioneer. Things are even
> >> further apart
> >> when comparing the Pioneer tuner performance to the PVR-x50 tuner
> >> performance. So cable performance is the same constant in both
> >> equations.
> >>
> >> I would guess that the real problem on the PVR-x50 series products
> >> is the
> >> poor performance of the tuner and analog sections, not poor
> >> performance of
> >> the ADCs or encoder hardware (or cable signal).
> >
> > If you want to compare apples to apples, you would need to play back
> > what is captured from the PVR-150 (with the highest quality settings)
> > through the same converters as your pioneer DVR. Blame could just as
> > easily be placed on the video card you chose to put in your myth box
> > or the settings you are using on either your PVR-150 or your video
> > card or maybe the video card driver itself.
>
> Perhaps you weren't following the entire thread, Brad. I had already
> written that decoder and video card performance is not an issue as DVDs
> played with my Myth setup look fantastic, actually better than the Pioneer.
> So no problem there.
>
> > Again, my PVR-150 looks much better than the Tivo I used to use and is
> > just about as good as going directly into my TV (after I bumped up the
> > bitrate/size settings to 720x480 and I think my bitrate is around
> > 8000). My money is on some setting you are using that makes it look
> > bad. If you post a sample of it maybe someone who knows more about
> > video compression could see what's happening.
>
> My bitrate is 6 AVG/8 PK but in my extensive efforts to make the PVR-x50
> look good I've had it as high as 9 with no joy. I have always run 720x480.
> There is no mistake being made. I've adjusted other settings, too, using
> v4l2 with no improvement. I did some extensive work with the Nvidia
> settings tool to get things color corrected and properly scaled, as well.
>
> > Oh.. I just re-read and see that you are using composite video. Do you
> > mean composite through RF? You could be getting interference from the
> > other components in your machine (like your power supply). Try it with
> > s-video.
>
> Been there, done that, no improvement. Besides, if there were interference
> problems would they not also affect the Pioneer which was stacked up with
> the same equipment?
>
> And before someone says "Maybe your card is broken" consider that I've got
> one -150 and on -250 and they both look equally poor.
>
> With all the comments on how PVR-x50's look better than Tivo I'm sure glad
> I didn't get a Tivo!
>
> Scott (PVR-x50 anti-apologist!)

What resolution are you outputting to the TV/Screen? The obvious thing is to 
make your resolution output to the TV/Screen as close to 720x480 as possible 
with 800x600 being a good choice.