[FFmpeg-devel] [PATCH] [v4] avcodec/vaapi_encode: add customized surface alignment

[Araz]

>>On Fri, Mar 22, 2024 at 11:35 AM Anton Khirnov <anton at khirnov.net> wrote:
>>Why this unnecessary complication? Just use two ints, or two uint8_t's
>>if you really need to save space, though that also seems unncessary as
>>this struct is allocated rarely and usually does not live long.

https://github.com/intel/libva/pull/794
The alignment range for log2_size of 4bit is in range of
[2**0, 2**15] = [1, 32768] this is large enough, or other way is to
directly use the alignment value, however I would want it to be in
powers of 2 and not any number, to force this condition, the common
way is to use log2_size(), which is using less bits and forcing
the alignment to be in powers of 2.

>>On Sun, Mar 24, 2024 at 5:38 PM Mark Thompson <sw at jkqxz.net> wrote:
>>What other users do you have in mind for this?  (Are you expecting
hwupload to use it as well, say?)
>>
>>If this is only used in VAAPI encode then I would suggest putting the
query there rather than adding new library API for it.
>>
>>Also agree with Anton that this form is unnecessarily confusing - just
make it a normal field, don't pack it like this.  (And possibly drop the
log2 as well?  That doesn't seem like it adds anything useful.)

The limitation is for AMD HW, and it is not limited to VAAPI, and for other
HW encoding protocols this limitation also exists.