Never had the urge to buy a Chromecast since my 5 Pi4/5 plays 4k HDR HEVC perfectly fine on my LG 65CX and the other tvs i have.
Does Android use OpenGL or Vulkan for this?
Android supports OpenGLES and Vulkan. I don't think it's used pretty much, because they use a lot of hardware acceleration for video playback. RPi does the opposite: It uses a lot of software decoding, which needs more processing power.
So both platforms might deliver the same performance on different hardware.
RPi does the opposite: It uses a lot of software decoding, which needs more processing power.
I thought RPI uses kernel mode setting (KMS) for video acceleration. Is this considered hardware acceleration?
Is this considered hardware acceleration?
No, KMS isn't the actual hardware acceleration layer:
How does the Android running Chromecast 4k do compare to LE on RPI4B for video hardware acceleration or graphical UI?
Does Android use OpenGL or Vulkan for this?
The Chromecast has an Amlogic S905Y3 chip with Mali G31 GPU inside and supports OpenGLES. It's a faster chip than the Broadcom SoC in the RPi4, and the OS runs from internal eMMC storage, but Android has a much greater general OS overhead so I usually find the Kodi GUI runs "about the same" on most Android devices with my (large) media collection as it does on an RPi4B's inferior but less loaded hardware.
Hardware Video Acceleration is something different. RPi4B supports only H264 (to 1080p) and HEVC (to 4K) whereas the Chromecast supports a much wider range of codecs. That said, most of the extra codecs Chromecast supports are legacy ones and the RPi4B can software decode the legacy media using them. The main real-world difference will be VP9 media support.
Note that RPi5 significantly outperforms RPi4.
