Hi!
I'm trying to work out where some latency is coming from in the system I'm working on.

The 'last' thing that happens before display, in our software at least, is a function that uses mmal/openmax to decode and draw an h264 video stream. This gets triggered on each full frame of video data. This function originates from 'hello_video' and is not much different in essence in the way it works.

I used chronos to time the beginning and the end of that function call and got roughly 0.0004 seconds, or 0.4ms. Every 10 frames or so there's a small hitch with up to ~2ms. But mostly it's around 0.4ms.

What I was wondering was if there's anything more that happens that could take much time after this? Before the frame is sent out to the monitor?
For example is there work on the hardware that happens after the software has done its part, per frame?

I don't care about any screen drawing or monitor latency as I did swap my two test monitors around and got the same results so I'm assuming that part is cancelled out.

Cheers, Fred