QSVEncC/NvEnc does not support 'mpeg-4 visual'.

[Selur]

Last I checked, NVEncC and QSVEncC both did not support MPEG-4 ASP through hardware decoding.

You might be right, it might be supported now.
Seem like
They changed:

--avhw                       use libavformat + hw decode for input

from

--avhw                       hw decode for input

(in the help output of NVEncC&Co)
and I didn't notice that.

Documentation over at https://github.com/rigaya/NVEnc/blob/mas....md#--avhw still lists only
MPEG1, MPEG2, H.264/AVC, H.265/HEVC, VP9, AV1, VC-1 as compatible to '--avhw'

=> Will do some testing and report back.

Cu Selur