I get strange artefacts, noise and blocks in very dark, black or near black areas of my encode, which are _not_ present in the source. How do I get rid of these?
Note: AFAIK, all approaches reduce compressability quite a bit. So be aware of that.
Answer 1:
This is a known issue discussed extensively in
this thread. One partical solution is to use an avisynth script containing
1. MarcFD's Mpeg2Dec3
2. Tom Barry's Unfilter
The script should look something like this:
#----------------------------------------
LoadPlugin("C:\Avisynth\Mpeg2Dec3.dll")
LoadPlugin("C:\Avisynth\Unfilter.dll")
Mpeg2Source("C:\Movie\Source.d2v")
LumaFilter(-2)
Unfilter (3,3)
#----------------------------------------
Lumafilter is a function of Mpeg2Dec3. So that, no further plugin is needed. Values for Lumafilter may differ here, so -1 or -3 might also work well. For more Information see the readme of Mpeg2Dec3.
Regarding the values for
Unfilter, the same applies. These are just the values I prefer. You will have to experiment to find out what suits your needs
Answer 2:
There is also a filter called Blockbuster by Sansgrip(?). It seems, however, that it is designed to get rid of blocks which were already in the source.
I 've never tried it but it is supposed to work well.
Please also read this thread for help:
http://forum.doom9.org/showthread.php?s=&threadid=45431