Very strange. My MPEG video files now play fine through omxplayer. I didn’t make any changes other than the several reboots yesterday, but now it works.
Does anyone know how the licencing process works? Does the OS contact some remote address with my licence number and PI serial, and wait for a confirmation to come back saying “yes, you can hardware decode now.”?
That’s the only reason I can think for the lag between updating the config file and hardware encoding being enabled.