Script for automated audio capture from Firefox to Telegram Desktop

pipefinder.sh

#!/usr/bin/env bash
set -euo pipefail

SLEEP_SEC=2
OUTPUT_APP=""
INPUT_APP=""
declare -A LINKS_DONE=()

usage() {
  cat <<EOF
Usage:
  $0 --output "Output App Name" --input "Input App Name" [--sleep SECONDS]
EOF
  exit 1
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --output) OUTPUT_APP="$2"; shift 2 ;;
    --input)  INPUT_APP="$2";  shift 2 ;;
    --sleep)  SLEEP_SEC="$2";  shift 2 ;;
    -h|--help) usage ;;
    *) echo "Unknown argument: $1"; usage ;;
  esac
done

if [[ -z "$INPUT_APP" || -z "$OUTPUT_APP" ]]; then
  echo "ERROR: --input and --output are required"
  usage
fi

cleanup() {
  echo
  echo "Resetting – removing PipeWire links ..."
  for key in "${!LINKS_DONE[@]}"; do
    out="${key%%|*}"
    in="${key#*|}"
    pw-link -d "$out" "$in" 2>/dev/null || true
  done
  exit 0
}
trap cleanup INT TERM

prune_links() {
  declare -A PORTS=()

  while read -r p; do
    [[ -n "$p" ]] && PORTS["$p"]=1
  done < <(pw-link -o -I | awk '{print $1}')
  while read -r p; do
    [[ -n "$p" ]] && PORTS["$p"]=1
  done < <(pw-link -i -I | awk '{print $1}')

  for key in "${!LINKS_DONE[@]}"; do
    out="${key%%|*}"
    in="${key#*|}"
    if [[ -z "${PORTS[$out]+x}" || -z "${PORTS[$in]+x}" ]]; then
      unset 'LINKS_DONE[$key]'
    fi
  done
}

echo "Intercepting audio:"
echo "  OUTPUT: $OUTPUT_APP"
echo "  INPUT : $INPUT_APP"
echo "  SLEEP : $SLEEP_SEC sec"
echo

last_sig=""

while true; do
  mapfile -t FL_IDS < <(pw-link -o -I | awk -v app="$OUTPUT_APP" '$0 ~ app ":output_FL" {print $1}')
  mapfile -t FR_IDS < <(pw-link -o -I | awk -v app="$OUTPUT_APP" '$0 ~ app ":output_FR" {print $1}')

  IN_FL="$(pw-link -i -I | awk -v app="$INPUT_APP" '$0 ~ app ":input_FL" {print $1; exit}')"
  IN_FR="$(pw-link -i -I | awk -v app="$INPUT_APP" '$0 ~ app ":input_FR" {print $1; exit}')"

  if [[ -z "${IN_FL:-}" || -z "${IN_FR:-}" || "${#FL_IDS[@]}" -eq 0 || "${#FR_IDS[@]}" -eq 0 ]]; then
    echo "One of the devices is missing – waiting..."
    last_sig=""
    prune_links
    sleep "$SLEEP_SEC"
    continue
  fi

  sig="IN_FL=$IN_FL IN_FR=$IN_FR FL=${FL_IDS[*]} FR=${FR_IDS[*]}"
  if [[ "$sig" != "$last_sig" ]]; then
    echo "Ports changed or appeared – ensuring links..."
    last_sig="$sig"
  fi

  for out in "${FL_IDS[@]}"; do
    pw-link "$out" "$IN_FL" 2>/dev/null || true
    LINKS_DONE["$out|$IN_FL"]=1
  done

  for out in "${FR_IDS[@]}"; do
    pw-link "$out" "$IN_FR" 2>/dev/null || true
    LINKS_DONE["$out|$IN_FR"]=1
  done

  prune_links
  sleep "$SLEEP_SEC"
done