[FFmpeg-user] Confusion about fieldmatch, decimate and framerate (now with yadif)

Nicholas Robbins nickrobbins at yahoo.com
Thu Nov 21 00:05:12 CET 2013

On Wed, 11/20/13, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
 Sorry, I fear that for different reasons I will not be 
 able to help you, still some comments / rants that may 
 or may not help:
<very informative rant removed>
 Finally, pullup was ported and now, you already 
 uploaded the second sample that works with 
 pullup but not fieldmatch. (I think it was you.)
NR: It wasn't

 The sample you uploaded does not show a 2:3 pattern 
 (and no 2:3:3:2 pattern) but a 3:3 pattern.
 I have no idea how this was made or how it is 
 supposed to work. (Did you make the sample?)
 fieldmatch does not seem to like it, it shows 
 surprising output on the console and I have no 
 idea if the original avisynth (or whatever) 
 filter has the same deficiency or not. (Can you 
 All this said, the sample looks interesting, if 
 you could explain where it comes from, perhaps 
 we can find out what has to be done.
 Sorry for the rant, Carl Eugen

No problem, it was informative. The source is a dumb rip of a DVD. I have some of my dvd's in storage in the attic ripped to a server for my Boxee.
The dvd's were ripped by :

$ dvdbackup -v  -rm -i /dev/sr0  -o $TMPDIR -M
$ mkisofs -quiet -o $ISONAME -dvd-video $TMPDIR/* 

Recently I realized I could use half as much space if I converted to x264 (even with crf 17) most videos worked fine. Some needed to be yadif'ed. although, I'm now realizing I yadif'ed things that shouldn't have been. I was basing the yadif decision on the "Interlaced" tag on the mkvs obtained by dumping the stream from the iso's via mplayer. I am now using yadif=deint=interlaced with better results.

The video in question is a TV miniseries made in the UK (Terry Pratchett's "Going Postal"). However, since i live in region 1, I assume it was remastered for the US. So I don't know how it wandered around 24p 25i, and 30i in the production stream.Interestingly other sources that should have similar origins don't have this problem "Hogfather" worked fine, but I might have started from the the DVD for that one, and not done the stupid iso step. Which seemed like a good idea at the time.

I could dig it out of storage to see if I get different results from the original. Would that be helpful?

Nick Robbins

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