More help with Multidecimate

Support for my Avisynth filters
Post Reply
stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

More help with Multidecimate

Post by stephen23 » Mon Jun 17, 2013 9:26 am

I use this lovely filter a lot, mainly to remove duplicate frames from 8mm telecine files prior to stabilising, and have arranged a smooth and efficient workflow.

I am having problems with a file which is not working properly in pass #1: mfile has missing frames at the beginning or the end.

The 8mm scan is done by Cinepost, with a Rank Turbo (truly high-end scanning!), is in DV-AVI PAL, but is interlaced with mismatched fields in VD. Your telecide filter fixes that, and I make and save a DV-AVI file (Cedocida 023) in VD.

I use this saved file in a simple script

avisource("C:\Users\me\Videos\Avisynth\yy12.avi")
converttoyuy2
multidecimate (pass=1)

load into a virgin VD then press Enter or "run video analysis pass", then immediately quit VD.

If I "dub", then mfile has the first few frames after 0 missing, e.g. 1-3 or 1-6. (Then of course the wrong frames are removed)
If I do a video analysis pass instead, the last few frames (e.g. 100 frames!) are missing. (The output stops before the end). VD's "progress" window indicates that these last frames are actually processed.

I thought I'd found a workaround by putting the selection markers at the beginning and end: worked once but now no difference.

Bit mysterious? To do with the Telecide? Be grateful for your help.

Stephen

User avatar
admin
Site Admin
Posts: 4002
Joined: Thu Sep 09, 2010 3:08 pm

Re: More help with Multidecimate

Post by admin » Tue Jun 18, 2013 6:23 am

Can you provide an unprocessed source sample file that will allow me to duplicate your issue?

stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

Re: More help with Multidecimate

Post by stephen23 » Tue Jun 18, 2013 1:44 pm

Thanks for swift reply

This is an excerpt - the original had 733 frames.

https://docs.google.com/file/d/0BxpFyO_ ... sp=sharing

Today "run video analysis pass" is working fine, with no loss of frames. Dubbing is variable - always some frames lost immediately after frame #0, between 1 and 10. Have tried trimming the beginning, also saving the file with XVID codec: still reliably drops a few frames.

stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

Re: More help with Multidecimate

Post by stephen23 » Mon Jul 01, 2013 3:01 pm

Did you reproduce the effect? Here:
Dubbing: always some frames omitted at beginning
Video analysis pass: now OK, no frames lost

User avatar
admin
Site Admin
Posts: 4002
Joined: Thu Sep 09, 2010 3:08 pm

Re: More help with Multidecimate

Post by admin » Mon Jul 01, 2013 5:18 pm

What settings are you using? If frames at the beginning look like duplicates due to your chosen threshold, then they will be lost.

stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

Re: More help with Multidecimate

Post by stephen23 » Tue Jul 02, 2013 4:09 am

I haven't run Multidecimate.exe (yet). This is the mfile.txt output from pass #1.
e.g.
0 0.000000
6 3.561256
7 0.692229
8 2.392039
9 3.160094
10 2.075680
11 0.643177
12 2.985938
13 4.780632
14 0.721382
15 2.465293
16 3.994452
17 2.074696
18 0.659269
19 3.883663
...etc
values for frames 1-5 missing.

User avatar
admin
Site Admin
Posts: 4002
Joined: Thu Sep 09, 2010 3:08 pm

Re: More help with Multidecimate

Post by admin » Tue Jul 02, 2013 9:17 pm

After you open the script in VirtualDub, just do File/Preview input...
Wait for it to play all the way through, then close VirtualDub.

When I do that with your sample I get this:

0 0.000000
1 32.687029
2 11.233306
3 0.665847
4 11.643914
5 2.946577
6 3.561256
7 0.692229
8 2.392039
9 3.160094
10 2.075680
11 0.643177
12 2.985938
13 4.780632
14 0.721382
15 2.465293
16 3.994452
17 2.074696
18 0.659269
19 3.883663
20 2.850370
...

Nothing missing for me.

stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

Re: More help with Multidecimate

Post by stephen23 » Wed Jul 03, 2013 5:35 am

Thanks for looking.
When I do that it consistently misses frames. And only with that particular avi file or subsections thereof.
It must be something to do with my PC - W7x64 Home Premium, nothing else running. Any idea what sort of thing would do it?

Fortunately "Video analysis pass" now seems to work reliably.

best wishes
Stephen

User avatar
admin
Site Admin
Posts: 4002
Joined: Thu Sep 09, 2010 3:08 pm

Re: More help with Multidecimate

Post by admin » Wed Jul 03, 2013 6:56 am

That's strange. Can you tell me which version of VirtualDub you are using?

Does it happen with the sample you gave me?

stephen23
Posts: 6
Joined: Mon Jun 17, 2013 5:10 am

Re: More help with Multidecimate

Post by stephen23 » Thu Jul 04, 2013 9:13 am

1.9.11, almost certainly X86.

With that sample (and its parent) and no other that I have found. (And I use this filter a lot)

Post Reply