This document discusses a few aspects of video quality

Output
======

The PVR350 can output via composite or s-video (RGB?? FIX)
The s-video signal is far superior from a video quality perspective.
If your tv doesn't have an s-video socket but does have an s-video mode,
you may be able to use an s-video to SCART convertor. (careful, some cheap
s-video/scart convertors don't work properly - if you get a black and white
picture try another)

Video Artefacts
===============

1. Faint diagonal lines seen on s-video signals sent through the scart plug.

These can be caused when the card outputs s-video and composite at the same time.
The solution is to use:
 ivtvctl -l 2
which sets s-video only

2. diagonal coloured lines appearing on recordings.

There is speculation that the Macrovision filter is being triggered. Reloading the
modules should fix this. (FIX - still relevant?)

3. black screen with diagonal white lines

Happens when the driver thinks you are using PAL, while the tuner or s-video
in signal is NTSC or vice versa. Check which tuner is autodetected or specified
to see if there is no mistake there.


MPEG Settings
=============

If you are experiencing visual artifacts (ghosting of people, etc.) you
probably want to play around with the dnr settings.

You can use ivtvctl or record-v4l2.pl to set them.

dnr_mode:
        0:  spatial and temporal noise removal filters
        1:  temporal only
        2:  spatial only
        3:  no noise filter

dnr_spatial:
        0..16:  0=no filtering  16=strongest filter
              (horizontal only, smoothing/lowpass)
dnr_temporal:
        0..16:  0=no filtering  16=strongest filter 
              (inter-frame (time dimension), averaging)

if you know mplayer's denoise3d or hqdn3d filter, then
dnr_spatial is the same as its first parameter, and dnr_temporal is the
same as its 3rd param.

if you set dnr_temporal too high (say 16) you'll get
motion blur effect.  if you set dnr_spatial too high, you get image
horizontaly blured.

dnr_type:  dunno, i couldn't find the effect of this
parameter. it doesn't change anything visible for me. any ideas?