Yes Pi5's CSI2 receiver supports virtual channels, and can write out up to 4 streams of data into memory.
However it also supports routing one stream of data directly to the Camera Front End (CFE). Libcamera is currently set up to do that with the image data, and the embedded metadata direct to memory.
If you're running multiple VCs, then it will need a slight re-architecture to send all the image data (and embedded metadata) to memory, and then the CFE to read from memory as required.
Streams support to handle VCs has only just been merged into the Linux kernel with 6.10, with patches for the CSI2 receiver and CFE being reviewed at the moment. The IdeasOnBoard dev doing the upstream work for us has been testing with FPD-Link as well as he is also maintainer of the couple of FPD-Link devices supported in the mainline tree. AIUI He has NOT been running it with libcamera though, so it is just writing the incoming data directly to SDRAM.
CM4 (actually all of Pi0-4 and CM1-4) only supports 2 data paths, and one of those is intended for the embedded metadata only so has very limited options.
However it also supports routing one stream of data directly to the Camera Front End (CFE). Libcamera is currently set up to do that with the image data, and the embedded metadata direct to memory.
If you're running multiple VCs, then it will need a slight re-architecture to send all the image data (and embedded metadata) to memory, and then the CFE to read from memory as required.
Streams support to handle VCs has only just been merged into the Linux kernel with 6.10, with patches for the CSI2 receiver and CFE being reviewed at the moment. The IdeasOnBoard dev doing the upstream work for us has been testing with FPD-Link as well as he is also maintainer of the couple of FPD-Link devices supported in the mainline tree. AIUI He has NOT been running it with libcamera though, so it is just writing the incoming data directly to SDRAM.
CM4 (actually all of Pi0-4 and CM1-4) only supports 2 data paths, and one of those is intended for the embedded metadata only so has very limited options.
Statistics: Posted by 6by9 — Tue Jun 25, 2024 6:24 am
