[mythtv-users] Image Quality PVR-500

[Brian Wood]

On Feb 18, 2007, at 1:01 PM, Brian Wood wrote:

>
> On Feb 18, 2007, at 12:03 PM, J. David Maino wrote:
>
>> I got my PVR-500 working with the help of the guys over at the IVTV
>> user
>> list, and now I have some weird issues with image quality. Here are
>> some
>> sample mpg files: http://psuae.org/mpg/index.html
>>
>> The ones labeled with mythtv at the end were recorded in mythtv and
>> the
>> ones without were taken using 'cat /dev/video[0|1] > /tmp/card[0|
>> 1]' and
>> using ivtv-tune to tune to the different channels. The quality
>> difference is most noticeable on card0.
>>
>> Anyone have any ideas why there's a lack of color on card0 when using
>> mythtv? Also, any help on the quality of the images would be
>> appreciated. I don't know if there's much I can do since that's a
>> Samsung tuner, which I know has a lot of problems, but any help you
>> could offer would be greatly appreciated.
>
> Now I know why they say a picture's worth a thousand words :-)
>
> First, you have "mouse teeth" on your "good" pictures, an interlace
> artifact, try de-interlacing to fix that, what method will depend on
> your CPU power and your ultimate display. Perhaps you're de-inting on
> playback and don't see that when you actually watch, but it's in the
> file.
>
> Looks like you haven't tuned the channel perfectly with Myth. This
> could be just the "Samsung Tuner Syndrome" or you could possibly be
> using the incorrect channel table.
>

One other thought- that could be garbage products due to overload.  
Doesn't the 500 card have an on-board amplifier that can be turned on  
and off? Perhaps you could try turning it off and/or putting an  
attenuator ahead of the card?