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Dup filter - Remove frames

Posted: Mon Jan 09, 2012 12:11 pm
by TheoRI
Dear admin

I am new to avisynth and virtualdub so please pardon my naive question.

My father and I are trying to digitize his super 8 collection.
We have built a projector that uses a CMOS based industrial camera to capture frame by frame the film, at reduced speed, as it rolles.
We are using the directshow driver of the camera and VirtualDub to do the capture

This results in random duplicate frames: ex 11123445

When I load the script in virtualdub and then output the file by "Save as AVI", it still outputs duplicate frames, without dropping the ones your script so well has identified...
# Remove Duplicate frames from super 8 Capture stream
# Using Dub AviSynth plug in
# http://rationalqm.us/dup/dupnew.html
#=============================================================================================

film="E:\TELECINE\input.avi" # source clip, please specify the full path here

# END VARIABLES, BEGIN SCRIPT
#=================================================================================================================================

SetMemoryMax(2000) #set this to 1/3 of the available memory
SetMTMode(5) #disable all MT calls if you are using a single core computer

Avisource(film).converttoYV12()
loadplugin("Dup.dll")

Dup(threshold=10,chroma=true,show=false,copy=false,maxcopies=10,blend=false,debug=true,log="e:\telecine\dup_log.txt")
#================================

The log file looks like this:
Dup: frm 0: Using frm 3
Dup: frm 1: Using frm 3
Dup: frm 2: Using frm 3
Dup: frm 3: Using frm 3
Dup: frm 4: Using frm 4
Dup: frm 5: Using frm 6
Dup: frm 6: Using frm 6
Dup: frm 7: Using frm 8
Dup: frm 8: Using frm 8
Dup: frm 9: Using frm 9
Dup: frm 10: Using frm 11
Dup: frm 11: Using frm 11
Dup: frm 12: Using frm 12
Dup: frm 13: Using frm 14
Dup: frm 14: Using frm 14
Dup: frm 15: Using frm 16
Dup: frm 16: Using frm 16
Dup: frm 17: Using frm 17
Dup: frm 18: Using frm 19
Dup: frm 19: Using frm 19
Dup: frm 20: Using frm 20

I would like the output to only include the unique frames
in this case 3 4 6 8 9 11 12 14 16 17 19 20

Can you please help?
This would be greatly appriecated

Best wishes for the New Year,
Theo

Re: Dup filter - Remove frames

Posted: Mon Jan 09, 2012 8:29 pm
by admin
Dup() does not remove frames. It replaces near equal frames with equal frames.

You need decimation. Before I tell you about that I need to know if there is an audio track or is it just video? If there is audio we have to maintain AV sync and our choices will be reduced.

Re: Dup filter - Remove frames

Posted: Mon Jan 09, 2012 10:51 pm
by TheoRI
There is no Audio involved, just video... decimate away
Theo

Re: Dup filter - Remove frames

Posted: Tue Jan 10, 2012 8:10 am
by admin
Try MultiDecimate to remove all duplicates.

http://rationalqm.us/multidecimate/multidecimate.html

Re: Dup filter - Remove frames

Posted: Sat Jan 14, 2012 5:46 pm
by TheoRI
Did try it and works great. Thanks!

Re: Dup filter - Remove frames

Posted: Sat Jan 14, 2012 9:33 pm
by admin
You're welcome. You might also have a look at DeDup(). MultiDecimate() is often preferable, however, due to its static scene protection feature.