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

Brad DerManouelian myth at dermanouelian.com
Wed Aug 13 02:14:46 UTC 2008


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.

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.

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.



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