They do? Anything meaningful?
Kubernetes, Chromium, Android, Go, TensorFlow, Dart, Angular, many more that I can’t recall off the top of my head or ever heard of.
Then all the research they publish, transformer, map reduce, bigtable, spanner, again the list goes on.
I don’t know what companies I’d rate as high as Google in terms of open source contribution and impact. RedHat. Maybe MS and Meta are close.
This being said I would expect they contribute a lot for ffmpeg, which was mentioned explicitly, since this is such a critical building block for them.