THE ONE TRUE SETUP

audio.sh

#!/bin/bash

export AUDIO_DEFAULT_CAPTURE=hw:PCH
export AUDIO_DEFAULT_PLAYBACK=hw:PCH

execd() {
  echo "$@" >&2
  "$@"
}

audio-cleanup() {
  jack_control ds dummy
  jack_control status || (killall jackd && jack_control start)
  jack_control sm || return $?

  pactl info || pulseaudio --start
  pulse-connect sink pulse-sink jack-sink
  pulse-connect source pulse-source jack-source
  pulse-connect source pulse-monitor jack-monitor
}

pulse-connect() {
  local dir="$1"; shift
  local jack_name="$1"; shift
  local pulse_name="$1"; shift

  jack_lsp | grep -q "$jack_name" && return

  pactl list "$dir"s | grep -q "Name: $pulse_name" && {
    pactl unload-module "$pulse_name"
  }

  pactl load-module module-jack-"$dir" \
    channels=2 client_name="$jack_name" \
    "$dir"_name="$pulse_name" \
    "$@"
}

audio-setup() {
  audio-cleanup

  jack_control ds alsa
  jack_control dps playback "$AUDIO_DEFAULT_PLAYBACK"
  jack_control dps capture "$AUDIO_DEFAULT_CAPTURE"

  local playback

  while [[ $# -gt 0 ]]; do
    local a="$1"; shift
    case "$a" in
      -o|--option)
        local opt_name="$1"; shift
        local opt_val="$1"; shift
        jack_control dps "$opt_name" "$opt_val"
      ;;
      *)
        if [[ -z "$playback" ]]; then
          playback=1
          jack_control dps playback "$a"
        else
          jack_control dps capture "$a"
        fi
      ;;
    esac
  done

  jack_control dp
  jack_control sm || return $?

  patch_pulse
}

jack_patch() {
  local a b
  paste <(jack_lsp | fgrep "$1" | sort) <(jack_lsp | fgrep "$2" | sort) \
    | while IFS="$TAB" read a b; do
      [[ -z "$a" ]] && break
      [[ -z "$b" ]] && break
      is-jack-connected "$a" "$b" || execd jack_connect "$a" "$b"
    done
}

is-jack-connected() {
  local source="$1"; shift
  local sink="$1"; shift

  jack_lsp -c "$source" | tail -n+2 | fgrep -q "$sink"
}

patch_pulse() {
  jack_patch system:capture pulse-source
  jack_patch system:playback pulse-sink
}