First, the pipe buffer between curl and ffmpeg will fill up (something like 64k) and then curl will be more and more delayed getting the next bit of audio from the server. Eventually the HTTP connection will fail. How and when that happens depends on exactly how the server is set up.
On my machine (Ubuntu) it stops after about 15 minutes.
You could increase the buffer size with pv or use a temporary file of course.
curl -L http://d.liveatc.net/klax_twr | ffmpeg -i - -filter:a atempo=0.5 -f s24le - | ffplay -f s24le -ar 8k -ac 2 -
First, the pipe buffer between curl and ffmpeg will fill up (something like 64k) and then curl will be more and more delayed getting the next bit of audio from the server. Eventually the HTTP connection will fail. How and when that happens depends on exactly how the server is set up.
On my machine (Ubuntu) it stops after about 15 minutes.
You could increase the buffer size with pv or use a temporary file of course.