rkdjpeg Hardware JPEG Decoder Driver
The RK3588, as well as the RK3566 and RK3568 (and possibly the RK3576? Its datasheet boasts similar performance specs for it but I don't have the register listing) have Rockchip's homegrown hardware JPEG decoder, which they refer to as "rkdjpeg" internally by the looks of it. In the TRM for the RK3588, this is called VDPU720.
In the RK3588, it can hardware decode JPEG up to 560 million pixels per second, which works out to around 4K@60fps. On the RK3566 and RK3568, it's less than that (half iirc) because rkdjpeg can be configured with multiple decoder cores.
This seems low priority because 4K MJPEG streams seem a little anachronistic outside of security CCTV setups.
@fratti has briefly looked at this IP on the RK3566 before, but not much came of it
- Figure out whether it's a good idea to abuse the stateful JPEG v4l2 interface for yet another stateless JPEG decoder. There are already two JPEG header parsers in the kernel for this purpose.
- Salvage anything that can be salvaged from the previous attempt
- https://youtu.be/EvKTOHVGNbg