> If this filter is meant to be same as existing zoompan but more precise, 
> then you should modify the original filter with a mode option for FP use.

Thing is I hesitated modifying the existing zoompan but there are a few things 
that don’t fit my use case and I didn’t want to update too many things:

- frame’s PTS is rewritten
- configurable output size is not dynamic (and is not evaluated in frame mode)
- if output aspect ratio is different than input aspect ratio, output image 
will be stretched

I can:

- add an option to enable PTS passthrough
- add “w” and “h” options on top of “s” options that would allow dynamic output 
size
- make sure computed crop size respect output aspect ratio

Would that be ok?

> I would suggest to add a 2nd FFFilter entry to
> libavfilter/vf_perspective.c
>
> with a zoompan user interface to access the already existing interpolation 
> code
> in vf_perspective.c
>
> we have bilinear and bicubic interpolation there and it should form a
> better basis for the implementation

Reusing vf_perspective.c interpolation implementations seems like a really 
great idea, I didn’t know they existed.

However I don’t understand the way you suggest I should do it.

Are you suggesting I should add “const FFFilter ff_vf_yazp = {}” in 
“vf_perspective.c” and move the zoompan logic there? If not, maybe what you’re 
suggesting has already been implemented in another filter and I can use it as 
an example to understand and reproduce it better?

Cheers
Quentin



_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".

Reply via email to