Apparently the Google Pixel has gotten a software upgrade to get YouTube HDR. So I'm wondering could the Nvidia Shield and the Sony Bravia tv's also be updated via software only. I read a long time ago that they didn't have the necessary hardware for Vp9.2 or vp9 profile 2, but maybe it can now be done via software?
There's a difference between having an on-chip silicon to handle all H264/VP9 decodes and having it decoded 'in software' and still be hardware accelerated.
The shield has 256 maxwell GPU cores capable of CUDA - there's no reason they cannot hardware-accelerate the decode using existing hardware. Instead of using a dedicated hardware decoder - it'd just use the GPU cores with compute instructions.
The shield would need a firmware update to the chipset.
Not just the usual Android software update, but a firmware update to the hardware itself. I think they are hesitant to do this.
Well that's a bummer that the Tegra X1 in the Shield doesn't seem to have VP9 profile 2 hardware decoding. Even if it could somehow do the format in software @ whatever resolution without dropping frames, Youtube probably won't serve the videos to the device because based upon past behavior they seem to only serve formats to devices that devices can decode in hardware.
All video decoding can be done in software if the processor can handle it. I would be surprised if these hardware couldn't.
Most of the Sony Bravias TVs from 2015 onward have the hardware capability for it. It's just up to Google to update YouTube to allow it.