[FFmpeg-user] minterpolate only frames 3, 8, 13, 18, etc.

[Moritz Barsnick]

Mark,

On Sun, Apr 05, 2020 at 04:53:26 -0400, Mark Filipak wrote:
> Correction... (This is not my day -- going stir crazy).

You have disputed it before, but here it goes again. You keep opening
new threads with the same or almost same topic by writing new emails.
This will make people miss responses, if one response goes to the one
thread while one is going to the other. (You have some five "telecine
5555" threads running - REALLY hard to follow.)

Please, if you make a correction (that can happen, admitted), *reply*
to you previous email instead of opening a new thread.

This would really help us to assist you. I myself keep getting lost in
your threads, and lose interest.

> ffmpeg -i IN -filter_complex
> "split[A][B],[A]drop((n+1)%10==3|(n+1)%10==8)[C],[B]drop(!((n+1)%10==3&!(n+1)%10==8)[D],[D]minterpolate(mi_mode=mci(mc_mode=obmc),scd=none)[E],[C][E]merge"

a) A comma ',' always chains two filters to each other. You have
"break" points after "[A][B]", and so on. These are separate filter
chains with dedicated "[]" inputs and outputs, so need to be separated
with semicolons ';'.

b) The mathematical expressions you are passing are understood by some
filters, but with a different syntax. For one, you have to tell the
filter for which of its options these expressions are valid, for the
other, you have to use ffmpeg expression syntax, and for the third, you
unfortunately may have to quote some characters.

c) For dropping frames, I suggest the "select" filter, obviously with
an inverse expression.

d) I see where you are going, and may try to help you construct a
command line. But see how far you can get first.

https://trac.ffmpeg.org/wiki/FilteringGuide
https://www.ffmpeg.org/ffmpeg-utils.html#Expression-Evaluation
(Sorry, no examples in the latter. There should be a lot on the list
and on StackOverflow.)

Cheers,
Moritz