Help with avisynth filters, removing grain, dust or spatial noise

[greyfalcon]

I normally record from my cable company HD receiver which is usually 1080i and fairly crisp quality, but I recently moved in a place I can't get decent cable. So i'm Installed a UHF/VHF antenna on my roof to capture ATSC however several of the shows I've recorder seem to be grainy or it might be spatial noise, I don't really know much about telling the difference. The feed seems to be 720p @ 59.940 fps so I'm using the script below to Decimate to back to 23.976 fps (hopefully i'm doing that right, I read several threads here)

I've seen several filters for removing grain and noise, but they have lots of modes that I don't really understand, so I was hoping you could look at the sample and better guide me towards what my options are.

LoadPlugin("C:\Program Files (x86)\megui\tools\dgindex\DGDecode.dll")
DGDecode_mpeg2source("D:\work\'video.d2v", cpu=4, info=3)
LoadPlugin("C:\Program Files (x86)\megui\tools\avisynth_plugin\ColorMatrix.dll")
ColorMatrix(hints=true, interlaced=true, threads=0)
LoadPlugin("C:\Program Files (x86)\megui\tools\avisynth_plugin\TIVTC.dll")
TDecimate(cycleR=3)
#denoise

From what I read using something like RemoveGrain(mode=2) is a good overall filter but I'm not sure if its the right choice for this project. Is it considered dust, grain or noise there are so many filters? Thanks for any help you can offer.

[jagabo]

You need a deblocking filter. And the video has been poorly deinterlaced.