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View Full Version : Decomb metric-based filtering


MrBunny
24th February 2003, 02:25
Hey guys, I was just thinking (quite the rarity) about hybrid clips again and was hoping I could get some opinions on the possibility and/or utility of having external filterschains triggered by decomb's decimate metrics. The syntax would probably be similar to Marc's MAM filter. It would allow extra flexibility with hybrid clips since you'd be able to choose exactly what filters to use when something is NTSC, and when it's FILM. This could be invaluable for those that think they have a nicer or better approach for a certain type of hybrid material, or just for experimentation. For example (I'll call the filter DecimateWrapper for now):

DecimateWrapper(cycle, threshold (a la decimate), filter(s) for below threshold, filter(s) for above threshold)

To mimic telecide().decimate(mode=3,cycle=5) behavior:
Telecide()
DecimateWrapper(cycle=5, threshold=0.5, decimate(mode=0,cycle=5), Convertfps(23.976).temporalsoften(3,5,5,mode=2,scenechange=10))

So anything below the threshold of 0.5 would be simply decimated as usual and anything above would be convertfps'd then tempsoftened.

Similarly, for decimate(mode=1,cycle=5) you could use:

DecimateWrapper(cycle=5, threshold=0.5, TomsMoComp(1,15,1), FieldDeinterlace().Decimate(mode=1, threshold=0.5, cycle=5))

In this case, you'd be able to use TomsMoComp instead of FieldDeinterlace for NTSC portions but still retain the nice mode=1 interpolation ability.

I guess some checks would need to be added to make sure the two filter setups come up with the correct fps, and i'm not even sure the initial cycle=x is necessary at all since the external filters would be the ones actually doing the frame manipulation. I don't know how hard it would be to impliment, but it shouldn't be too hard as it's more of a meshing of ideas than anything revolutionary.

Just a thought :)

Mr. B

InfoCynic
27th February 2003, 16:27
I could see a lot of value in somthing like this... I've been doing TONS of hybrid clips lately... seems like a good idea, at least worth a shot and not too tricky...

OUTPinged_
2nd March 2003, 23:38
I don't think implementing this in "dumb" way would pay back enough to be worth the hassle.

InfoCynic
3rd March 2003, 02:41
I don't know how much hybrid material you deal with, and "hybrid" anime that can easily be dealt with by mode 2 doesn't count, but there is a real need for better tools. Currently the options are apply ivtc to the whole thing and deal with jerkiness in the NTSC portions or use mode 1 and lose a ton of compressibility and stick an interpolated frame in there that isn't really needed. For material like TNG (typically about 80% FILM / 20% NTSC), DS9 (95% FILM), B5 (hard to say exactly, headers are wrong), it's really annoying to have to waste the space encoding the material at 30fps when so much of it would only need 24fps.

It's either this or multiple frame rates in one stream, as per the other thread... but we need something. :(

Atamido
4th March 2003, 01:47
Matroska can easily handle multiple framerates in one file as it doesn't use set framerates. Each frame has its own timecode of when it needs to be displayed. Of course, this won't be useful for this particular application until there is an encoding application that supports it. AVISynth 3.0 anyone?

mf
4th March 2003, 12:55
Originally posted by Pamel
Matroska can easily handle multiple framerates in one file as it doesn't use set framerates. Each frame has its own timecode of when it needs to be displayed. Of course, this won't be useful for this particular application until there is an encoding application that supports it. AVISynth 3.0 anyone?

http://forum.doom9.org/showthread.php?s=&threadid=47203