[mythtv-users] pvr-350 slighly fuzzy picture

[Jeff Wormsley]

Nick wrote:
>> Can anyone give me any pointers on how to "sharpen"
>> the picture.  I'm starting to wonder if all my work
>> was in vain...cool features are great, but lossing
>> picture quality is not something I want.  By the way,
>> I have tried swapping out cables....didn't help.
>> Right now I'm using the same S-Video cable that I use
>> for my DVD player (fine picture cable).  I've also
>> tried about 3 different coax (input) cables.
> 
> Make sure the PVR card is not using (heavy) noise reduction - by
> default I think it is enabled when the ivtv driver is loaded - you can
> control it using ivtvctl. Also, make sure you have a recent firmware
> installed for the PVR card - the ivtv output in the syslog will let
> you know if you are using a buggy firmware.

One other thing that may be affecting you.  The PVR card's tuners seem 
to be a little on the weak side, meaning that if you don't have a strong 
input signal, you'll get poor captures.  To check, you can try one of 
two things.  One, move your rig temporarily to as close to where the 
cable input comes into your house as possible, thus bypassing any 
splitters and/or long cable runs.  The other is capturing an s-video 
(preferred) or composite source, such as from a DVD player or your cable 
box output, and compare that to your cable capture (use the ivtvctl 
utility to set up the card using the -p parameter), and capture from the 
command line ( cat /dev/video0 > /tmp/test_capture.mpg ).  If the close 
to the cable entry capture (or the s-video capture) looks significantly 
better than the cable input at your normal location, you may have a weak 
input to the card.  Eliminate any unneeded splitters and/or look into 
getting a signal amp (installed as close to the incoming cable line as 
possible).  Google around for info on the best way to use a signal amp, 
because sometimes too much amplification is as bad or worse than no 
amplification (and can cause problems with a cable modem, if you have one).

One other possibility is using the wrong frequency table (such as hrc 
instead of standard catv), but for me that usually means getting no 
signal, not a poor one.

HTH,
  Jeff.