[FFmpeg-devel] [PATCH] avfilter: add framerate video filter

[Marton Balint]

On Sat, 29 Aug 2015, Carl Eugen Hoyos wrote:

> Marton Balint <cus <at> passwd.hu> writes:
>
>> Consider you have a 25i source, and you want 30i (60p for display)
>> 
>> Are you referring to this filter chain for deinterleaving?
>> 
>> -vf il=l=d:c=d,framerate=30,il=l=i:c=i,yadif=1
>> 
>> And this for deinterlacing?
>> 
>> -vf yadif=1,framerate=60,interlace,yadif=1
>
> The original task afaiu was not to provide a progressive 
> output stream (in that case, deinterlacing first is of 
> course correct) but to provide an interlaced stream.
> (I don't care about the reason.)

The last filter (yadif=1) is only there to visually check the results, as 
I have a progressive display. If you are encoding to a 30i file, you can 
remove the yadif=1 filter form the filter chain.

>
> I thought - and it seems that Robert agrees now - that 
> apart from being faster, deinterleaving has a good 
> chance of providing better quality.
>
>> The second is much, much better.
>
> Why do you think so?

I have tried it, and seen it with ffplay.

> (Apart from the fact that I don't understand the 
> filterchain "interlace,yadif": It never makes sense imo.)

It's there to be able to visually see the result. Remove the yadif filter 
from the end of the filter chain if you are encoding a file.

Regards,
Marton