For example, my desktop with an i7-2600k (that's a Sandy Bridge CPU from 2011) has zero issues playing 4K60 VP9 footage on YouTube in Chrome with CPU decoding, yet on Netflix with the same Chrome I'm arbitrarily restricted to 720p H.264 video.
See in Widevine there are a number of “levels”, the highest being when it can decode, decrypt and push to the frame buffer all in a secure zone. This can not be achieved (atm, well atleast the time of my research into the matter) with widevine on Desktop, so in such a setup widevine will only decrypt upto 720p content.
When running on Android and ARM this is possible and you can get 1080p, which is why you can get cheap android based tv sticks (even the old Amazon Fire TV sticks) supported 1080p but your gaming rig and Chrome could not.
Don’t work for Widevine, Google, NetFlix or anyone else for that matter. Just a nerd with too much time on my hands so I looking into this stuff. Any corrections welcomed :-D
> As far as I understand it there are 3 security levels to widevine Level1 being the highest and 3 being the lowest.
> Level 1 is where the decrypt and decode are all done within a trusted execution environment (As far as I understand it Google work with chipset vendors such as broadcom, qualcomm, etc to implement this) and then sent directly to the screen.
> Level 2 is where widevine decrypts the content within the TEE and passes the content back to the application for decoding which could then be decoded with hardware or software.
> Level 3 (I believe) is where widevine decrypts and decodes the content within the lib itself (it can use a hardware cryptographic engine but the rpi doesn't have one).
> Android/ChromeOS support either Level1 or Level3 depending on the hardware and Chrome on desktops only seems to support Level 3. Kodi is using the browser implementation (at least when kodi is not running on Android) of widevine which seems to only support Level 3 (So decrypt & decode in software) and therefore can not support hardware decoding. But that doesn't mean that hardware decoding of widevine protected content can not be supported on any mobile SoC. Sorry if I gave that impression.
> When a license for media is requested the security level it will be decrypted/decoded with is also sent and the returned license will restrict the widevine CDM to that security level.
> I believe NetFlix only support Level 1 and Level 3, which is why for a while the max resolution you could get watching NetFlix on chrome in a desktop browser was 720p as I believe that was the max resolution NetFlix offered at Level 3 and we had to use Edge/IE(iirc) to watch at 1080p as it used a different DRM system (PlayReady) and why atm Desktop 4k Netflix is only currently supported on Edge using (iirc) Intel gen7+ processors and NVidia Pascal GPUs (I don't know if AMD support PlayReady 3.0 on their GPUs as I don't have one so not really had the desire to investigate, I'm guessing that current Ryzen CPUs do not as they currently don't have integrated GPUs).
In particular, is it due to DRM requirements, or pure performance? I suspect it's the former.