[FFmpeg-user] simple bob -- How?

[Mark Filipak (ffmpeg)]

On 12/29/2020 03:41 AM, Paul B Mahol wrote:
> On Tue, Dec 29, 2020 at 5:51 AM Mark Filipak (ffmpeg) <markfilipak at bog.us>
> wrote:
> 
>> I seek a way to do simple bob (i.e. repeat fields at 2xFPS) with no other
>> filtering. Can you help me?
>>
>> I suppose I could do something like this:
>> -filter_complex
>>
>> "split[s1][s2],[s1]separatefields[A1][a1],[s2]separatefields[A2][a2],[A1][A2]weave[Ao],[a1][a2]weave[ao],[Ao][ao]merge"
>> (Kindly forgive any mistakes -- I haven't done anything like this in a
>> couple of months.)
>> But I thought I'd ask here for an easier way.
>>
>> These gave pretty good results. They're listed from best to worst:
>> bwdif
>> yadif=send_field_nospatial
>> yadif=send_field
>>
>> However, I suspect that, in addition to mechanical frame changes, they're
>> also making some
>> (unwanted) cosmetic changes.
>>
>> Based on what's written in the documention, these seemed promising:
>> separatefields,doubleweave
>> separatefields,tinterlace=mergex2
>>
>> But they produced surprising and undesired results.
>>
>> Optional Reading:
>>
>> I also tried this:
>>
>> separatefields,select=eq(mod(n,4),0)+eq(mod(n,4),3),weave
>>
>> It's not what I actually want, but I tried it because it doesn't make
>> sense to me -- weave together
>> fields N%4==0 and N%4==3? (Really? Modulo-4? fields 0 & 3?) -- so, because
>> it doesn't make sense to
>> me, I thought I might learn something interesting. So, what happened?
>> "Conversion failed!" is what
>> happened. Why it's cited as an example (
>> https://ffmpeg.org/ffmpeg-filters.html#Examples-121) in the
>> documentation is a mystery to me.
>>
> 
> After so much time you still struggle a lot, buy some GUI tools and be
> happy ever after.

You're not helping, Paul.

> You probably missing \ to escape every , inside expressions.

I'm running in Windows.