Video filter help please.

[Fleabag]

How do I go about filtering out "video noise" without making the low-light portions of videos look "blocky"?

[Agent_007]

http://forum.videohelp.com/threads/235245-Avisynth-denoise-filters-comparison-%28WARNING-56K-MODEM!!%29
that thread has some comparison shots between different denoise filters of AVIsynth. Maybe you will get some tips from those images.

[Fleabag]

Sorry, but that thread doesn't answer my question about filtering out "video noise" without making the low-light portions of videos look "blocky"

[Jan Gruuthuse]

You don't gonna like what you are reading next.
It is all a trial by error. Take a small test sample, and try applying the filter(s) and change one parameter at a time. See if the situation improves or get worse. If the video is already compressed, most likely you never get the result you want. Agent_007 is proposing to use Avisynth. Applying filters always has the risk of degrading the picture. I never use these, don't have the time or patience to do this.
Try other filter(s) our combination.
If you want more information: Avidemux noise filter
Check in avidemux Preferences: Video: Default Postprocessing: Unmark the 3 options and see if it improves. If it does not: lower strength.
Document every step on paper what you are doing. when you get the result you want: make new paper with steps you did make and archive it very well.
Perhaps other users will share there secrets on filter usage?