kvazaar: ensure input pucture dimensions are divisible by 8

[DarthSim]

Hey there 👋

Kvazaar requires dimensions of the input kvz_picture to be divisible by 8. Otherwise, encoding fails and aborts the whole program. Unfortunately, Kvazaar's API doesn't do this for us.

[farindk]

The better way to do that is probably to implement query_encoded_size in the encoder plugin (version 3). I can have a look at that.

Or we may need both. A quick test gave me this result

heif-enc: image.c:59: kvz_image_alloc: Assertion `(width % 2) == 0' failed.

So I assume query_encoded_size should round up to multiples of 2 and then maybe we have to allocate images with multiples of 8 to match some memory alignment issues?

[farindk]

I have implemented this in a different way (see above). Please check whether this is also ok on your data.

[DarthSim]

It works, thanks! 👍

[farindk]

Thanks for testing and your initial patch.