My point is to create a continuous video stream with overlay that will change depending on external events. Like YouTube radio channels, where the song name is changing depends on which track is currently playing.
I saw one of the interesting ways with using several ffmpeg instances and local streams for audio and video: one ffmpeg is playing audio to local port, and other combining it with video, taking the audio source from local audio stream. So I can change the audio during the stream without restarting it.
My question is, can I use the same scene for changing the overlay. Let's say I need to change the song name on the screen, is there any ways to do so with ffmpeg?