I'm having trouble figuring out precisely which filter graph operations are supported by each of the available hardware acceleration methods. I know, for example, that almost all of these methods perform simple operations like scaling, but what about more complicated ffmpeg filters like the new v360 filter or the mestimate filter?
There's this page (https://trac.ffmpeg.org/wiki/HWAccelIntro) that everyone finds when researching hardware accel with ffmpeg but it mostly touched on encoding and decoding and not filtering.
Filters which can operate upon frames on the GPU will have names that identify them as such e.g. scale_vaapi overlay_qsv or yadif_cuda. Run ffmpeg -filters | grep vaapi to identify all VAAPI supported filters in your build.