How to add an audio track to a live broadcast using FFmpeg?

Question

Audio

There are online cameras, but they only give a video stream, and it’s boring for ordinary people to watch cameras without sound. Recently, static cameras installed around the city began broadcasting to one of the local iptv and feature requests came from subscribers.
I would like to add some kind of audio track to the live broadcast, whether it is a pre-recorded file or an online radio station. I am using ffmpeg transcoding to change image size and bitrate.
The ffmpeg mana mostly describes working with files, there is very little about online streams.
Maybe someone faced a similar problem?
Stream from the camera without sound in hls can be viewed here

http://video.iluki.ru:81/matrosov_museum_102/index.m3u8

(via VLC)

Answer 1

Yes, there is no difference, streams or files.
Here is a working example for your stream and the first radio found on google:
I have nowhere to stream now - all other options will only concern encoding, streaming, buffers, etc.
It is more interesting if the file is recorded. Here you need to tell him that he would spin in a circle. This will help here: video.stackexchange.com/questions/12905/repeat-loo... , and the command will be like this:
instead of a specific file, there may be a playlist here. Everything else is the same as for the live audio stream example.
If you understand the -map option, you can take audio tracks from other videos.