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View Full Version : What to do with interlace artifacts left after IVTC (24p in 50i)?


Maxiuca
11th July 2009, 01:42
I've got a 50i MPEG2 stream that was made directly from 24p source (so it wasn't speed up to 25 fps like it should have been, but instead encoded as 24p in 50i with all that interlacing and field doubling)
I've recovered the progressive frames using SeparateFields().DoubleWeave().SelectEvery(25,1,3,5,7,9,11,13,15,17,19,21,23) but the resulting frames still have some interlacing "artifacts" left (parts of the image appear to be still interlaced). Since this interlacing parts seem to appear in blocks I assume they were caused by MPEG2 compression which does not handle interlaced stream well.

Is there a way (filter or some smart script) to remove those artifacts?

neuron2
11th July 2009, 01:58
What to do? Post a link to an unprocessed source sample.

Maxiuca
11th July 2009, 13:14
right, sorry, here is the sample
http://maxiuca.com/part.rar

It is a short sample, but it shows the problem. Please keep in mind that the quality is really bad. It's a 2.35:1 ratio image in a 4:3 PAL frame and the encode is also bad.

Anyway applying SeparateFields().DoubleWeave().SelectEvery(25,0,2,4,6,9,11,13,15,17,19,21,23) recovers the progressive frames. But if you go for example to frame 77 (after recovering progressive frames) you'll notice a lot of "mice teeth" left in some parts of the image.

Didée
11th July 2009, 13:52
There is the Vinverse() script/plugin. It was made with exactly these kind of artifacts in mind.
It's listed on http://avisynth.org/mediawiki/External_filters

Maxiuca
11th July 2009, 15:30
Wow, it's amazing, works like charm on default settings.

No I just need something for the chroma noise/artifacts. cnr2 maybe? But I've noticed cnr2 produces ghosting artifacts and when you lower the settings to get rig of the artifacts then it no longer denoises.

thewebchat
12th July 2009, 03:50
On the sample you posted, MVDeGrain completely removes the chroma noise in the sample at the default strength. Also, to fix the PAL "telecine", you can do TFM.TDecimate(cycle=25).