Turn normalization on/off

[oskarburman]

Hi, is it possible to chain in normalization and then manually be able to turn it on or off depending on if you want it or not? If this is not possible would it be something that could be implemented?

[vitoyucepi]

Hi @oskarburman,
Do you have a specific normalization in mind, as there are more than one?
In the liquidsoap you can use:

• normalize
• replaygain
• autocue

The answer may vary depending on the type of normalization.

[oskarburman]

Oh.. and this is for unknown http streamed source or from alsa line in.

[vitoyucepi]

I don't think you can do this without patching the `normalize' function.

liquidsoap/src/libs/audio.liq

Lines 105 to 187 in cde4dad

	def replaces normalize(
	~id=null(),
	~target=getter(-13.),
	~up=getter(10.),
	~down=getter(.1),
	~gain_min=-12.,
	~gain_max=12.,
	~lufs=false,
	~lookahead=getter(0.),
	~window=getter(.5),
	~threshold=getter(-40.),
	~track_sensitive=true,
	~debug=null(),
	s
	) =
	let (s, rms) =
	if
	lufs
	then
	s = lufs_builtin(id=id, window=window, s)
	(s, {lin_of_dB(s.lufs())})
	else
	s = rms.smooth(id=id, duration=window, s)
	(s, s.rms)
	end
	v = ref(1.)
	frame = frame.duration()
	gain_min = lin_of_dB(gain_min)
	gain_max = lin_of_dB(gain_max)
	def update() =
	target = lin_of_dB(getter.get(target))
	threshold = lin_of_dB(getter.get(threshold))
	rms = rms()
	if
	rms >= threshold
	then
	if
	v() * rms <= target
	then
	up = 1. - exp(0. - frame / getter.get(up))
	v := v() + up * ((target / rms) - v())
	else
	down = 1. - exp(0. - frame / getter.get(down))
	v := v() + down * ((target / rms) - v())
	end
	v := max(gain_min, min(gain_max, v()))
	end
	end
	def target_gain() =
	lin_of_dB(getter.get(target)) / rms()
	end
	s =
	if
	null.defined(debug)
	then
	source.run(
	s,
	every=null.get(debug),
	{
	log.debug(
	"rms: #{rms()} / #{lin_of_dB(getter.get(target))}\tgain: #{v()} / #{
	target_gain()
	}"
	)
	}
	)
	else
	s
	end
	s = source.on_frame(s, update)
	s = if track_sensitive then source.on_track(s, fun (_) -> v := 1.) else s end
	amplify(id=id, {v()}, delay_line(lookahead, s)).{
	rms=rms,
	gain={v()},
	target_gain=target_gain
	}
	end

[smimram]

You should be able to do something like

s = switch([({!condition},normalize(s)),({true},s)])

where s is your source and condition is a boolean variable.

[vitoyucepi]

Won't there be a "jump" when switching from delay_line(lookahead, s) to s?

[smimram]

Ah right, let me add a new parameter to the function then...