Rebroadcast (transcode) the audio of a video livestream over Icecast.

rebroadcast.sh

#!/bin/bash
# You can use streamlink to extract the stream URL, e.g.:
# PL_URL=$(streamlink --stream-url https://livestream-website-url best)

# Generally figured out from this gist...
# https://gist.github.com/keiya/c8a5cbd4fe2594ddbb3390d9cf7dcac9

PL_URL=https://some.owncast-server.tv/hls/1/stream.m3u8

while ! curl -s $PL_URL | grep -q offline; do
  ffmpeg -re -i $PL_URL \
    -c:a libfdk_aac \
    -profile:a aac_he_v2 -ab 48k \
    -content_type 'audio/aac' \
    -vn -f adts \
    icecast://source:hackme@localhost:8000/some-name

  sleep 1
  echo "restarting ffmpeg"
done

echo "Stream is offline"