With DGMPGDec, is cpu=4, iPP=true good with telecined source?

[the_free_account]

I'm trying to encode from telecined NTSC source material, with 3 progressive frames for every 2 interlaced frames.

DGMPGDec's Mpeg2Source() has a parameter cpu= that controls postprocessing and a parameter iPP= that controls whether postprocessing is done per frame or per field.

If I use MPEG2Source(cpu=4,iPP=true), it's my understanding that postprocessing will be OK on the 30% interlaced frames but FUBAR the 70% progressive frames.

If I do the opposite -- MPEG2Source(cpu=4, iPP=false)-- I believe the reverse should be true. That is, progressive frames OK and interlaced frames messed up.

So, which setting, if any, should I used for telecine source material?

Thanks,
-Mike

[scharfis_brain]

load the mpeg without any postprocessing
then IVTC the video and then to the postprocessing
using blindpp(cpu=4,iPP=false)

[Mug Funky]

hey, scharfi? does blindPP take hints from mpeg2dec? i suppose it's a moot point because DVDs are pretty much always on quant 1 or 2.

i'd do ipp=true, but only if the source really needs deblocking.

[scharfis_brain]

hey, scharfi? does blindPP take hints from mpeg2dec?i]

I do NOT know...

the hint I gave was only a BIG assumption, not tested at all...

[Cyberia]

Originally posted by the_free_account
If I use MPEG2Source(cpu=4,iPP=true), it's my understanding that postprocessing will be OK on the 30% interlaced frames but FUBAR the 70% progressive frames.

If I do the opposite -- MPEG2Source(cpu=4, iPP=false)-- I believe the reverse should be true. That is, progressive frames OK and interlaced frames messed up.

This is an accurate statement. We are aware of the problem and will be fixing it in a future release by setting the iPP flag on a per frame basis, so postprocessing will be correct 100% of the time.

Unfortunately development is temporarily delayed until Don returns.

[Video Dude]

Originally posted by Cyberia
This is an accurate statement. We are aware of the problem and will be fixing it in a future release by setting the iPP flag on a per frame basis, so postprocessing will be correct 100% of the time.
I wrote a script so the ipp flag is set on a per frame basis.

Add your own BlindPP parameters, but just don't change the ipp value. You might want to play with the IsCombed threshold to match your clip. Refer the Decomb readme for more info about the threshold. I have not tested the script on a wide range of sources but it performed well on my test clips.



video = AviSource("C:\video.avi")

If_Interlaced = video.BlindPP(ipp=true)

If_Progressive = video.BlindPP(ipp=false)

test1 = ConditionalFilter(video, If_Interlaced, video, "IsCombed(video, threshold=20)", "=", "true", show=false)

test2 = ConditionalFilter(test1, If_Progressive, test1, "IsCombed(video, threshold=20)", "=", "false", show=false)

return test2