analogue composite to hdmi and lock signal

[G4WIM]

Hi guys, yet another question.

This is one I've solved in the past but have lost the 'recipe'.

I need to convert an analogue video signal from a FM rx to HDMI and generate a lock / signal present signal.

In the past I think I used an LM1881 plus 567 PLL chip for the lock signal.

Now perhaps I should use a RPI plus a usb video dongle for the conversion and some external signal detection for the lock signal.

I do have a cheap composite to HDMI converter but yet to determine how well it works with a noisy signal but would still need to generate a reliable lock signal.

Any comments / ideas ?

Regards Tim

[G4WIM]

I rediscovered an old design I had filed away using an LM1881 and NE567 for analogue lock detect - works very nicely.
The analogue to HDMI converter only has limited tolerance for weak signals with poor sync and drops out if the picture is anything less than about a P3.
I think I'll try a BATC dongle and RPI to see if that's any better under weak signal conditions.