A couple of observations.
Generally GStreamer will manage to achieve zero copy passing of buffers from the likes of libcamerasrc to many consumers.
The use of a tee component almost certainly means it has to copy the image data from the one source buffer to 2 of more output buffers, so you've dropped a huge amount of memcpying into the system.
You're likely to be overloading the ISP. libcamerasrc, v4l2convert, and v4l2h264enc all use the ISP, and the overall throughput on CM4 is around 180MPix/s under fully ideal situations. 1080p is just over 2MPix/frame, so 1080p60 is 120MPix/s. Use it 3 times and you're trying to process around 360MPix/s.
The H264 encoder is only rated for 1080p30. 1080p50 can normally be achieved if the system isn't doing huge numbers of other tasks (it's generally memory bandwidth). 1080p60 is very much on the edge for most situations.
Generally GStreamer will manage to achieve zero copy passing of buffers from the likes of libcamerasrc to many consumers.
The use of a tee component almost certainly means it has to copy the image data from the one source buffer to 2 of more output buffers, so you've dropped a huge amount of memcpying into the system.
You're likely to be overloading the ISP. libcamerasrc, v4l2convert, and v4l2h264enc all use the ISP, and the overall throughput on CM4 is around 180MPix/s under fully ideal situations. 1080p is just over 2MPix/frame, so 1080p60 is 120MPix/s. Use it 3 times and you're trying to process around 360MPix/s.
The H264 encoder is only rated for 1080p30. 1080p50 can normally be achieved if the system isn't doing huge numbers of other tasks (it's generally memory bandwidth). 1080p60 is very much on the edge for most situations.
Statistics: Posted by 6by9 — Mon Feb 12, 2024 10:27 am