Hmmm, this test points to a hbargraph gating behavior in its display only,
although I did not run it for a long time:
import("stdfaust.lib");
Tg = 0.4;
zi = an.ms_envelope_rect(Tg);
//gain = hslider("Gain [unit:dB]",-10,-70,0,0.1) : ba.db2linear;
gain = 0.01; // -40 dB - ok in Octave (I get -44.744 dB)
sig = no.noise * gain;
level = zi : ba.linear2db : *(0.5);
//process = level, attach(sig, (sig : level : hbargraph("test",-70,0)));
process = sig : level <: _, hbargraph("test",-70,0);
On Wed, Jul 7, 2021 at 12:50 PM Juan Carlos Blancas <[email protected]>
wrote:
> Hi Klaus,
>
> Same here, it seems there is something with ms and rms_envelope.
>
> Best,
> Juan Carlos
>
> import("stdfaust.lib");
>
> rms(n) = _ : square : mean(n) : sqrt;
> square(x) = x * x;
> mean(n) = float2fix : integrate(n) : fix2float : /(n);
> integrate(n,x) = x - x@n : +~_;
> float2fix(x) = int(x*(1<<20));
> fix2float(x) = float(x)/(1<<20);
>
> Tg = 0.4;
> zi = an.ms_envelope_rect(Tg);
> ziR = an.rms_envelope_rect(Tg);
>
> process = no.noise*1.737 *
> ba.db2linear(hslider("[0]g[unit:dB]",-20,-95,-10,0.1)) <:
> attach(_, rms(ma.SR*Tg) : ba.linear2db : hbargraph("[1]rms",-95,0)),
> attach(_, sqrt(zi) : ba.linear2db :
> hbargraph("[2]sqrt(ms_envelope_rect)",-95,0)),
> attach(_, ziR : ba.linear2db : hbargraph("[3]rms_envelope_rect",-95,0));
>
>
> > El 7 jul 2021, a las 9:59, Klaus Scheuermann <[email protected]>
> escribió:
> >
> > Hi all,
> > I did some testing and
> >
> > an.ms_envelope_rect()
> >
> > seems to show some strange behaviour (at least to me). Here is a video
> > of the test:
> > https://cloud.4ohm.de/s/64caEPBqxXeRMt5
> >
> > The audio is white noise and the testing code is:
> >
> > import("stdfaust.lib");
> > Tg = 0.4;
> > zi = an.ms_envelope_rect(Tg);
> > process = _ : zi : ba.linear2db : hbargraph("test",-95,0);
> >
> > Could you please verify?
> >
> > Thanks, Klaus
> >
> >
> >
> > On 05.07.21 20:16, Julius Smith wrote:
> >> Hmmm, '!' means "block the signal", but attach should save the bargraph
> >> from being optimized away as a result. Maybe I misremembered the
> >> argument order to attach? While it's very simple in concept, it can be
> >> confusing in practice.
> >>
> >> I chose not to have a gate at all, but you can grab one from
> >> misceffects.lib if you like. Low volume should not give -infinity,
> >> that's a bug, but zero should, and zero should become MIN as I mentioned
> >> so -infinity should never happen.
> >>
> >> Cheers,
> >> Julius
> >>
> >>
> >> On Mon, Jul 5, 2021 at 10:39 AM Klaus Scheuermann <[email protected]
> >> <mailto:[email protected]>> wrote:
> >>
> >> Cheers Julius,
> >>
> >>
> >>
> >> At least I understood the 'attach' primitive now ;) Thanks.
> >>
> >>
> >>
> >> This does not show any meter here...
> >> process(x,y) = x,y <: (_,_), attach(x, (Lk2 :
> vbargraph("LUFS",-90,0)))
> >> : _,_,!;
> >>
> >> But this does for some reason (although the output is 3-channel
> then):
> >> process(x,y) = x,y <: (_,_), attach(x, (Lk2 :
> vbargraph("LUFS",-90,0)))
> >> : _,_,_;
> >>
> >> What does the '!' do?
> >>
> >>
> >>
> >> I still don't quite get the gating topic. In my understanding, the
> meter
> >> should hold the current value if the input signal drops below a
> >> threshold. In your version, the meter drops to -infinity when very
> low
> >> volume content is played.
> >>
> >> Which part of your code does the gating?
> >>
> >> Many thanks,
> >> Klaus
> >>
> >>
> >>
> >> On 05.07.21 18:06, Julius Smith wrote:
> >>> Hi Klaus,
> >>>
> >>> Yes, I agree the filters are close enough. I bet that the shelf is
> >>> exactly correct if we determined the exact transition frequency, and
> >>> that the Butterworth highpass is close enough to the
> >> Bessel-or-whatever
> >>> that is inexplicably not specified as a filter type, leaving it
> >>> sample-rate dependent. I would bet large odds that the differences
> >>> cannot be reliably detected in listening tests.
> >>>
> >>> Yes, I just looked again, and there are "gating blocks" defined,
> >> each Tg
> >>> = 0.4 sec long, so that only ungated blocks are averaged to form a
> >>> longer term level-estimate. What I wrote gives a "sliding gating
> >>> block", which can be lowpass filtered further, and/or gated, etc.
> >>> Instead of a gate, I would simply replace 0 by ma.EPSILON so that the
> >>> log always works (good for avoiding denormals as well).
> >>>
> >>> I believe stereo is supposed to be handled like this:
> >>>
> >>> Lk2 = _,0,_,0,0 : Lk5;
> >>> process(x,y) = Lk2(x,y);
> >>>
> >>> or
> >>>
> >>> Lk2 = Lk(0),Lk(2) :> 10 * log10 : -(0.691);
> >>>
> >>> but since the center channel is processed identically to left
> >> and right,
> >>> your solution also works.
> >>>
> >>> Bypassing is normal Faust, e.g.,
> >>>
> >>> process(x,y) = x,y <: (_,_), attach(x, (Lk2 :
> >> vbargraph("LUFS",-90,0)))
> >>> : _,_,!;
> >>>
> >>> Cheers,
> >>> Julius
> >>>
> >>>
> >>> On Mon, Jul 5, 2021 at 1:56 AM Klaus Scheuermann <[email protected]
> >> <mailto:[email protected]>
> >>> <mailto:[email protected] <mailto:[email protected]>>> wrote:
> >>>
> >>>
> >>> > I can never resist these things! Faust makes it too
> >> enjoyable :-)
> >>>
> >>> Glad you can't ;)
> >>>
> >>> I understood you approximate the filters with standard faust
> >> filters.
> >>> That is probably close enough for me :)
> >>>
> >>> I also get the part with the sliding window envelope. If I
> >> wanted to
> >>> make the meter follow slowlier, I would just widen the window
> >> with Tg.
> >>>
> >>> The 'gating' part I don't understand for lack of mathematical
> >> knowledge,
> >>> but I suppose it is meant differently. When the input signal
> >> falls below
> >>> the gate threshold, the meter should stay at the current
> >> value, not drop
> >>> to -infinity, right? This is so 'silent' parts are not taken into
> >>> account.
> >>>
> >>> If I wanted to make a stereo version it would be something like
> >>> this, right?
> >>>
> >>> Lk2 = par(i,2, Lk(i)) :> 10 * log10 : -(0.691);
> >>> process = _,_ : Lk2 : vbargraph("LUFS",-90,0);
> >>>
> >>> Probably very easy, but how do I attach this to a stereo
> >> signal (passing
> >>> through the stereo signal)?
> >>>
> >>> Thanks again!
> >>> Klaus
> >>>
> >>>
> >>>
> >>> >
> >>> > I made a pass, but there is a small scaling error. I think
> >> it can be
> >>> > fixed by reducing boostFreqHz until the sine_test is nailed.
> >>> > The highpass is close (and not a source of the scale error),
> >> but I'm
> >>> > using Butterworth instead of whatever they used.
> >>> > I glossed over the discussion of "gating" in the spec, and
> >> may have
> >>> > missed something important there, but
> >>> > I simply tried to make a sliding rectangular window, instead
> >> of 75%
> >>> > overlap, etc.
> >>> >
> >>> > If useful, let me know and I'll propose it for analyzers.lib!
> >>> >
> >>> > Cheers,
> >>> > Julius
> >>> >
> >>> > import("stdfaust.lib");
> >>> >
> >>> > // Highpass:
> >>> > // At 48 kHz, this is the right highpass filter (maybe a
> >> Bessel or
> >>> > Thiran filter?):
> >>> > A48kHz = ( /* 1.0, */ -1.99004745483398, 0.99007225036621);
> >>> > B48kHz = (1.0, -2.0, 1.0);
> >>> > highpass48kHz = fi.iir(B48kHz,A48kHz);
> >>> > highpass = fi.highpass(2, 40); // Butterworth highpass:
> >> roll-off is a
> >>> > little too sharp
> >>> >
> >>> > // High Shelf:
> >>> > boostDB = 4;
> >>> > boostFreqHz = 1430; // a little too high - they should give
> >> us this!
> >>> > highshelf = fi.high_shelf(boostDB, boostFreqHz); // Looks
> >> very close,
> >>> > but 1 kHz gain has to be nailed
> >>> >
> >>> > kfilter = highshelf : highpass;
> >>> >
> >>> > // Power sum:
> >>> > Tg = 0.4; // spec calls for 75% overlap of successive
> >> rectangular
> >>> > windows - we're overlapping MUCH more (sliding window)
> >>> > zi = an.ms_envelope_rect(Tg); // mean square: average power =
> >>> energy/Tg
> >>> > = integral of squared signal / Tg
> >>> >
> >>> > // Gain vector Gv = (GL,GR,GC,GLs,GRs):
> >>> > N = 5;
> >>> > Gv = (1, 1, 1, 1.41, 1.41); // left GL(-30deg), right GR
> >> (30), center
> >>> > GC(0), left surround GLs(-110), right surr. GRs(110)
> >>> > G(i) = *(ba.take(i+1,Gv));
> >>> > Lk(i) = kfilter : zi : G(i); // one channel, before summing
> >> and before
> >>> > taking dB and offsetting
> >>> > LkDB(i) = Lk(i) : 10 * log10 : -(0.691); // Use this for a mono
> >>> input signal
> >>> >
> >>> > // Five-channel surround input:
> >>> > Lk5 = par(i,5,Lk(i)) :> 10 * log10 : -(0.691);
> >>> >
> >>> > // sine_test = os.oscrs(1000); // should give –3.01 LKFS, with
> >>> > GL=GR=GC=1 (0dB) and GLs=GRs=1.41 (~1.5 dB)
> >>> > sine_test = os.osc(1000);
> >>> >
> >>> > process = sine_test : LkDB(0); // should read -3.01 LKFS -
> >> high-shelf
> >>> > gain at 1 kHz is critical
> >>> > // process = 0,sine_test,0,0,0 : Lk5; // should read -3.01
> >> LKFS for
> >>> > left, center, and right
> >>> > // Highpass test: process = 1-1' <: highpass, highpass48kHz;
> >> // fft in
> >>> > Octave
> >>> > // High shelf test: process = 1-1' : highshelf; // fft in Octave
> >>> >
> >>> > On Sat, Jul 3, 2021 at 1:08 AM Klaus Scheuermann
> >> <[email protected] <mailto:[email protected]>
> >>> <mailto:[email protected] <mailto:[email protected]>>
> >>> > <mailto:[email protected] <mailto:[email protected]>
> >> <mailto:[email protected] <mailto:[email protected]>>>> wrote:
> >>> >
> >>> > Hello everyone :)
> >>> >
> >>> > Would someone be up for helping me implement an LUFS
> >> loudness
> >>> analyser
> >>> > in faust?
> >>> >
> >>> > Or has someone done it already?
> >>> >
> >>> > LUFS (aka LKFS) is becoming more and more the standard for
> >>> loudness
> >>> > measurement in the audio industry. Youtube, Spotify and
> >> broadcast
> >>> > stations use the concept to normalize loudness. A very
> >>> positive side
> >>> > effect is, that loudness-wars are basically over.
> >>> >
> >>> > I looked into it, but my programming skills clearly
> >> don't match
> >>> > the level for implementing this.
> >>> >
> >>> > Here is some resource about the topic:
> >>> >
> >>> > https://en.wikipedia.org/wiki/LKFS
> >> <https://en.wikipedia.org/wiki/LKFS>
> >>> <https://en.wikipedia.org/wiki/LKFS
> >> <https://en.wikipedia.org/wiki/LKFS>>
> >>> <https://en.wikipedia.org/wiki/LKFS
> >> <https://en.wikipedia.org/wiki/LKFS>
> >>> <https://en.wikipedia.org/wiki/LKFS
> >> <https://en.wikipedia.org/wiki/LKFS>>>
> >>> >
> >>> > Specifications (in Annex 1):
> >>> >
> >>>
> >>
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >
> >>>
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >>
> >>> >
> >>>
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >
> >>>
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >> <
> https://www.itu.int/dms_pubrec/itu-r/rec/bs/R-REC-BS.1770-3-201208-S!!PDF-E.pdf
> >>>
> >>> >
> >>> > An implementation by 'klangfreund' in JUCE / C:
> >>> > https://github.com/klangfreund/LUFSMeter
> >> <https://github.com/klangfreund/LUFSMeter>
> >>> <https://github.com/klangfreund/LUFSMeter
> >> <https://github.com/klangfreund/LUFSMeter>>
> >>> > <https://github.com/klangfreund/LUFSMeter
> >> <https://github.com/klangfreund/LUFSMeter>
> >>> <https://github.com/klangfreund/LUFSMeter
> >> <https://github.com/klangfreund/LUFSMeter>>>
> >>> >
> >>> > There is also a free LUFS Meter in JS / Reaper by
> >> Geraint Luff.
> >>> > (The code can be seen in reaper, but I don't know if I
> >> should
> >>> paste it
> >>> > here.)
> >>> >
> >>> > Please let me know if you are up for it!
> >>> >
> >>> > Take care,
> >>> > Klaus
> >>> >
> >>> >
> >>> > _______________________________________________
> >>> > Faudiostream-users mailing list
> >>> > [email protected]
> >> <mailto:[email protected]>
> >>> <mailto:[email protected]
> >> <mailto:[email protected]>>
> >>> > <mailto:[email protected]
> >> <mailto:[email protected]>
> >>> <mailto:[email protected]
> >> <mailto:[email protected]>>>
> >>> >
> >>>
> >> https://lists.sourceforge.net/lists/listinfo/faudiostream-users
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users>
> >>>
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users>>
> >>> >
> >>>
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users>
> >>>
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users
> >> <https://lists.sourceforge.net/lists/listinfo/faudiostream-users>>>
> >>> >
> >>> >
> >>> >
> >>> > --
> >>> > "Anybody who knows all about nothing knows everything" --
> >> Leonard
> >>> Susskind
> >>>
> >>>
> >>>
> >>> --
> >>> "Anybody who knows all about nothing knows everything" -- Leonard
> >> Susskind
> >>
> >>
> >>
> >> --
> >> "Anybody who knows all about nothing knows everything" -- Leonard
> Susskind
> >
> >
> > _______________________________________________
> > Faudiostream-users mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/faudiostream-users
>
>
>
> _______________________________________________
> Faudiostream-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/faudiostream-users
>
--
"Anybody who knows all about nothing knows everything" -- Leonard Susskind
_______________________________________________
Faudiostream-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/faudiostream-users
