Question on Video decoding

[Technologov]

Docs "4.5.2. Hardware 2D Video Acceleration for Windows Guests" -
it says "overlays" and "color space conversion".
But modern video codecs are way more complex than that. Something like MPEG-H/HEVC/H.265 or AOmedia AV1 can barely be pushed even on host, without full hardware acceleration, which must include:
1. parsing +
2. zip-like-decompression (entropy decoding)
3. overlays
4. color space conversion
5. motion vector prediction (+compensation)
6. (de-)quantization (frequency transform)
7. deblocking filter

Who knows what else I forgot... ?
Anyway, my question: is there any good cross-platform framework to do full-video-decoding of ALL steps and ALL layers, and for multiple codecs? Something that can be "passed" on to the "host OS" ? Something universal, like OpenGL ?
I think DirectShow (Windows only) and VLC framework (GPL-only) do come to mind. But is there anything better ? Mac OS seems to have CoreVideo, but I know little about it. and Android MediaServer...
I would love to get good multimedia performance from VirtualBox eventually including modern codecs + 4K UltraHD video decoding, which does require full acceleration to work anyhow.
Currently any kind of 4K video results in terrible frame drop in VirtualBox guest. (Windows 7 on Windows 7 and many other combinations tested, with several codecs.)

Hint: BTW My Samsung Galaxy S9 (Android 8 ) pushes 4K/UltraHD video at 60 fps for both MPEG-4-AVC, and HEVC/H.265 and VP9 video codecs super-fluidly without any framedrops. Most (host) PCs are incapable of it.
Just shows how much accelerated video decoding is becoming necessary nowadays. (while two decades ago I could watch DVD-quality MPEG-2 video on any Pentium-II class PC without any special hardware).