upmpdcli songcast sender script

Digital-Songcast

#!/bin/sh
# Place this file into /usr/share/upmpdcli/src_scripts

/usr/lib/luvi_modules/luvit-hbm10/scsender.lua $2

mpd.conf

#
# Fragment only, showing the audio_output parameters
#

# Configuring audio outputs
audio_output {
        type            "alsa"
        name            "ALSA"
        device          "softvol"
        mixer_control   "Master"
        enabled         "yes"
}
audio_output {
        type            "fifo"
        name            "FIFO"
        path            "/tmp/mpdfifo"
        format          "44100:16:2"
        enabled         "no"
}

scsender.lua

#!/usr/bin/luvit

-- Songcast Sender script for upmpdcli
-- Requires:
--   luvit [https://github.com/luvit/luvit]
--   lit-uuid [https://github.com/gsick/lit-uuid]

local fs = require("fs")
local spawn = require("childprocess").spawn
local uv = require("uv")

-- Toggle MPD audio output to FIFO
os.execute("mpc enable only FIFO >/dev/null")

-- Helper function to parse a string into hex presentation
local string = string or {}
function string.tohex(str)
  return (str:gsub('.', function (c)
    return string.format('%02X', string.byte(c))
  end))
end

-- Get a MAC address from wlan0 or eth0
local function mac()
  local mac
  local addresses = uv.interface_addresses()
  for name, info in pairs(addresses) do
    if name == "wlan0" or name == "eth0" then
      for _, v in pairs(info) do
        if v.family == "inet" then
          mac = v.mac
          break
        end
      end
    end
  end
  return mac
end

-- Generate a uuid from the MAC address
local function uuid()
  local UUID = require("uuid")
  local mac = mac()
  local uuid
  if mac then
    uuid = UUID(mac:tohex())
  else
    uuid = UUID()
  end
  return uuid
end

-- Read persistent UDN
local function udn()
  local udn = fs.readFileSync("/var/lib/upmpdcli/udn")
  if not udn then
    udn = uuid()
    fs.mkdirpSync("/var/lib/upmpdcli")
    fs.writeFileSync("/var/lib/upmpdcli/udn", udn)
  end
  return udn
end

local udn = udn()
local port = 6600
local name = args and args[2] or hostname

local args = {
    "-f", "/tmp/mpdfifo",
    "-A", "44100:16:2:1",
    "-a", 0,
    "-u", udn,
    "-n", name,
    "-p",
}

-- Signal handler
local sigterm = uv.new_signal()
uv.signal_start(sigterm, "sigterm", function(signal)
  -- Toggle MPD audio output back to ALSA
  os.execute("mpc enable only ALSA >/dev/null")
  os.exit(1)
end)

-- Spawn mpd2sc
local mpd2sc = spawn("/usr/bin/mpd2sc", args)

mpd2sc.stderr:on("data", function (data)
    process.stderr:write(data)
end)

mpd2sc.stdout:on("data", function (data)
    local s = ("Ok %s %s"):format(port, data)
    process.stdout:write(s)
end)

upmpdcli.conf

#
# Fragment only, showing the Songcast Receiver parameters
#

#sclogfilename = /var/log/scmpdcli.log
#scloglevel = 3
scplaymethod = alsa
sccvttype = NONE
scsendermpdport = 6600