>>365468867
NVENC and NVDEC, Intel's Media SDK (QSV) and AMD's AME AMdec all support mp3 as one of the hardware accelerated formats, yeah, due to being able to use them in video streams. 
Hard to find those specs but they're out there. Look at documentation of things like AVPro and software like plex, it's not great and most people forget to install chipset decode support because it's not obvious. Just installing LAAV splitter is a huge performance boost for things like that when you can override windows default behavior to use your native SoC instead (with some caviats) 
The audio hardware is hard to get details on decode/encode matrix lists. 
https://github.com/Nevcairiel/LAVFilters/releases