1. You may want to try animeivtc.
2. the imagesplice thing is not very efficient when used repetitively. You're better off doing it manually (i.e. trim(1,902) ++ imagesource("903.png").converttoyv12() ++ imagesource("903.png").converttoyv12()...)
Compression-wise, replacing frames doesn't really matter because it's only a few frames. As long as you don't change things too much, it won't hurt compression
also, don't forget audiodub, or you will lose audio in those regions. this is an example:
a=last
b=a.trim(1,902) ++ imagesource("903.png").converttoyv12() ++ imagesource("903.png").converttoyv12() ++ a.trim(904,1000)
audiodubex(b,a)
3. I have had the same problem in vdub. Just ignore it. Give AvsP a try too.
Afaik, rec. 601 means that colormatrix is unnecessary.
definitions/examples:
ringing
haloing and
more extreme example
film grain(prob. not found in anime i think)
noise film grain is a type of noise
example of severe blocking
order of filters, a general guide:
source
deinterlace/ivtc
make mod16 with borders(usually not required)
deblock
degrain/denoise
sharpen
replace frames
resize/crop
trim
crop before resize if there are black borders. other wise, use the crop-like functioning of resize. Read
this
each filter builds off the previous one, so just use common sense
For example, you don't want to sharpen before degraining because
sharpening (usually) amplifies noise, giving the degrainer a harder time.
A note on blocking: find a high motion area, copy the frame to the gimp/photoshop/whatever, and zoom in about 400%. If you see blocks (not pixels) in areas of motion or dark areas, then deblock. I prefer deblock_qed.