The only apps that could be looking at the serial interface for this data ("serial_notify_thread.cpp: ") realistically would be external apps (ie, outside the empeg) like the video display generator from a while back. They'd have to set notify=1 anyway and live with the consequences.

Anybody else that needed this information inside the empeg (userland apps) I suspect would much rather grab it from /proc than parsing the serial line themselves. I'd say turn it on internally and always strip from the serial unless notify=1 is explicitly in config.ini.

If it truly is a problem, couldn't you add more indirection? Have the player dump to ttyS0 (and internally duplicate to ttyS1) and whatever software that wants to have complete control over the serial output from the player could watch that, while your massaged output could go over ttyS1 & /proc. Or does the serial hack apply to all serial ports? Maybe I'm making this more complicated than it should be. That's what I get for armchair kernel-hacking