[mythtv-users] Recording/live-tv video quality (aka do, PVR150 encoders suck?)

David Brodbeck gull at gull.us
Mon Jan 28 23:21:39 UTC 2008

On Jan 28, 2008, at 5:54 AM, Yan Seiner wrote:

> Charles H. Chapman wrote:
>> Well, I for one agree with you.  The encoding from the PVR card (a  
>> 250
>> in my case) is inferior to the source material, even using S-video  
>> from
>> the DirecTV box.  One problem in particular is the apparent lack of
>> luminance AGC in the tuner.  On a normal TV this is done in  
>> hardware (or
>> maybe software in newer TVs) but it seems to be missing from the
>> hardware/software of the 250.  The result is that scenes,  
>> particularly
>> lettering, on a mostly white screen get washed out.
> Some of  that may be due to drivers and / or environmental conditions.
> (Broadcast signal quality and strength).

Also, the signal quality in analog cable is often pretty horrible.   
Even on "real TVs" I've often seen symptoms of undermodulation (poor  
contrast) or overmodulation (tearing, audio buzzing on white scenes)  
on cable feeds.  I would hope DirecTV would be better, but I'm not  
sure the signal from a set-top box is ever really "broadcast"  
quality.  Consumer devices almost always take liberties with the  
signal to cut costs.

Another problem is that computer video cards and monitors rarely seem  
to have the contrast range of an NTSC TV.  This is especially true of  
LCD monitors.  When watching TV or even DVDs on computers, I've often  
had to choose between washing out the highlights or having the dark  
areas disappear.

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