Crash or silence when using compressor.multiband.interactive

[hbiedka]

Describe the bug
When I am using compress.multiband.interactive, liquidsoap does not work properly:

• If the Icecast output in mp3 format is set up, app crashes and throws an error as below:

liquidsoap: psymodel.c:576: calc_energy: Assertion `el >= 0' failed.
Aborted (core dumped)

• If not (eg. Icecast2 but with Vorbis encoding), Liquidsoap streams a silence.

The same script works properly without compress.multiband.interactive.

To Reproduce
My code looks like this:

#postprocessing function
def orban(dry)

    radio = normalize(target=-17., window = 0.03, gain_min= -32., gain_max = 0., dry)
    
    #multiband compressor - THIS DOES NOT WORK!
    radio = compress.multiband.interactive(id="vitalizer",radio)

    # Initial compression low ration - this works OK
    comp_attack = interactive.float(min=0.,max=20.,step=0.5,"comperssor_attack",unit="ms",0.5)
    comp_release = interactive.float(min=1.,max=500.,step=1.,"comperssor_release",unit="ms",1.0)
    comp_thr = interactive.float(min=-60.,max=0.,step=1.,"comperssor_threshold",unit="dB",-36.0)
    comp_ratio = interactive.float(min=1.,max=10.,step=0.1,"comperssor_ratio",unit="",1.0)
    comp_gain = interactive.float(min=0.,max=20.,step=0.1,"comperssor_gain",unit="dB",6.)
    comp_window = interactive.float(min=0.,max=10.,step=0.1,"comperssor_window",unit="s",0.)
    
    radio = compress(attack = comp_attack, release = comp_release, threshold = comp_thr, ratio=comp_ratio, gain = comp_gain, window = comp_window, radio)

    wet = limit(radio)

    c = interactive.float("wetness", min=0., max=1., 1.)
    output = dry_wet(c, dry, wet)
    
    #set web service
    interactive.harbor(port=11000)

    #backup set data
    interactive.persistent("/var/log/emiter/orban.json")

    #return output
    output
end

this function is between request.dynamic and input.harbor fallback (live and playouts/playlist) and ouptut.icecast x2 (program stream in mp3 and Ogg Vorbis) and output.file (program recording to .ogg files)

Expected behavior
Script works properly with and without multiband compressor.

Version details

• OS: Docker container based on image liquidsoap-main:v2.0.2
• Version 2.0.2

Install method
As above

[toots]

Hi.

Thanks. This looks like a bug in the floating point data returned by the operator. I've assigned it to @smimram maybe he could help take a look at this.

[smimram]

The compressor might return values outside the [-1,1] range which could cause the issue. Could you try using the clip operator to ensure that, e.g. by replacing output by clip(output) and tell us if it improves the situation?

[hbiedka]

Hi,

I have changed output for clip(output) and it does not changed anything.

[toots]

I've been hit by this one as well and I hope that the upcoming changes to float array with the latest clipping patch to ocaml-lame here: https://github.com/savonet/ocaml-lame will fix it.

[toots]

Upon futher investigation, it turns out that nan values are the one making lame crash. There's a patch in ocaml-lame but it's not usable in liquidsoap at the moment.

Unless this is really pressing I'd recommend to wait for the upcoming 2.0.4 release, it will include the fix.