There is NO equivalent IC out there. For that reason, I had to make an OSD board using two '819s a gated oscillator and video sync chip to do the same thing. It was a PIA, but won't go obsolete any time soon. There are some simple circuits posted on the web to do this. This was a starting point for me, but I needed higher res,smaller characters, and three lines of 20 char read out! The gated oscillator was the tricky part, and mine runs at 28MHz to make it all work as planned.
If you find an alternative chip, let me know...
Ron