[FFmpeg-user] -pix_fmt yuv420p and deinterlacing

[Andy Furniss]

Katherine Frances wrote:
> Kia ora,
>
> *Andy*: thanks very much for this tip! Will add that filter to the script
> as I definitely want to deinterlace.
> Do you recommend this over *yadif*, or do I need to combine *scale* with a
> deinterlacing filter?

-vf scale=interl=1 Has nothing to do with de-interlacing it would be
needed more if you wanted to keep the interlacing.

yadif can de-interlace 422 input so if you used that *first* it
shouldn't matter. It would be wrong to convert 422 to 420 without
-vf scale=interl=1 if you then later de-interlaced, so the order
of filters matters.

yadif can produce field rate or frame rate output. It's field rate
that will look worse if you mess up the 422 to 420 conversion.

What to do depends on your content. If there's lots of motion then
field rate de-interlace (yadif=1) will look better. If it's interlaced
but low motion you will get away with frame rate (yadif=0).
Depending on what the masters are they may not be interlaced to start
with.

The right thing to do depends on what the output is for and what the
input really is - there is no right way as such.