[FFmpeg-devel] [PATCH v1 1/2] lavf/vf_transpose: add exif orientation support

Jun Li junli1026 at gmail.com
Tue May 28 09:25:54 EEST 2019


On Mon, May 27, 2019 at 7:52 AM Nicolas George <george at nsup.org> wrote:

> Jun Li (12019-05-27):
> > I compared the perf between vflip and this patch before, they take almost
> > the same time, around 9ms for a frame.
> > Hflip is a little special, but surely I can update the patch to avoid
> frame
> > copy, and it will be as fast as hflip.
> >
> > But still this is duplicated feature with vflip/hflip, the only benefit I
> > can think of is rotate180.
> > Previously we need chain two filter (vflip + hflip) to do rotate180, here
> > we only need one.
>
> Please note that there are two separate issues interacting here: having
> separate filters, having separate code.
>
> Merging the features of a filter into a more generic one is, IMHO, a
> good thing. In this instance, it makes the rest of the code simpler.
>
> But that does not mean you have to duplicate the code. You should almost
> never duplicate the code. What you should do is make sure the two
> filters are using the same code, i.e. calling the same functions to do
> the actual work.
>
>
Thanks for pointing that out. I updated the version and merged the existing
flip operation into transpose, removed my previous implementation.
https://patchwork.ffmpeg.org/patch/13311/
https://patchwork.ffmpeg.org/patch/13312/

Thanks a lot for your code review.

Best Regard,
Jun

Regards,
>
> --
>   Nicolas George
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