bpm throws Error 4: Undefined variable bpm

[Mikulskii]

Took an example from The Liquidsoap Book, but it doesn't work:

s = mksafe(playlist("..."))
s = bpm(s)
thread.run(every=1., {print("BPM: #{s.bpm()}")})
output(s)

Output:

At bpm.liq, line 2, char 4-8:
s = bpm(s)

Error 4: Undefined variable bpm

lufs and rms are working properly. Tried on versions 2.1.2 and 2.2.2 - Windows & Ubuntu(via opam)

[rrolla]

Hey @Mikulskii looks like s object is modified if you call it directly on real source

try like this

musicSource = mksafe(playlist(id="musicSource", "/mnt/test/bpm"))

musicSourceBpm = bpm(id="bpm", musicSource)

def detectBpm()
    metadata = musicSource.last_metadata() ?? []
    title = "#{metadata['artist']} - #{metadata['title']}"
    bpm = musicSourceBpm.bpm()
    bpmWithTitle = "BPM: #{string_of(int_of_float(bpm))} #{title}"
    print(bpmWithTitle)
end

def startDetectBpm()
    thread.run(delay=5.0, (fun() -> begin detectBpm() {} end))
end

def onMetadataHandler(metadata)
    startDetectBpm()
end

musicSource.on_metadata(onMetadataHandler)

And look whats happened on track change, maybe for you also always return 0
see #2871

[Mikulskii]

Hey @rrolla !
Strangely, I get the same error

musicSourceBpm = bpm(id="bpm", musicSource)

Error 4: Undefined variable bpm

[vitoyucepi]

Hi @Mikulskii,
Have you installed liquidsoap via opam in windows and ubuntu?
Can you list all installed opam packages with opam list?
I think the bpm function depends on soundtouch.

[Mikulskii]

Hi @vitoyucepi! Ah, that's the thing.
I installed soundtouch and the case moved forward. Thanks!
opam is only on Ubuntu.