KVR Audio

texture · Post by **texture** » Sun Jun 20, 2004 11:18 pm

Anyone know of a decent spectrogram VST?

Something like this (except as vst or dx):
http://www.visualizationsoftware.com/gram.html

Miles1981 · Post by **Miles1981** » Mon Jun 21, 2004 8:25 am

I'm programming one... My waterfall analyzer should have a waterfall as well as a spectrogram. VST and standalone, and as it takes time, it wouldn't be fully available before a month, I suppose

- I will make it available to shut down the waterfall or the spectrogram or the view-meter, in order not to use too much CPU when not needed -

texture · Post by **texture** » Mon Jun 21, 2004 8:42 pm

Cool

Let us all know when its ready!

Space Boy · Post by **Space Boy** » Mon Jun 21, 2004 8:58 pm

I'm also working on one. A few months away though.

aMUSEd · Post by **aMUSEd** » Mon Jun 21, 2004 9:18 pm

Closest I know of is Inspector:

http://www.elementalaudio.com/products/ ... index.html

There is a DX one that looks very good indeed but I try not to use DX effects myself:

http://www.brainspawn.com/products/SpectR-Pro/

Pity this is not in VST format too.

For a useful waveform visualisation thingy there's also Bram's Exoscope:

http://bram.smartelectronix.com/

btw - I think Voxengo have brought one out too recently (and a couple of their eq's do visualisation too)

Muff Wiggler · Post by **Muff Wiggler** » Mon Jun 21, 2004 9:21 pm

surely you mean

s(m)exoscope

one of the coolest names ever!

aMUSEd · Post by **aMUSEd** » Mon Jun 21, 2004 9:26 pm

Muff Wiggler wrote:surely you mean

s(m)exoscope

one of the coolest names ever!

Yeah - that one

Space Boy · Post by **Space Boy** » Mon Jun 21, 2004 9:39 pm

A Spectrogram is different to a spectrum. Spectrum is 1D and displays frequency versus amplitude at a single instance in time.

A Spectrogram is 2D, with frequency on one axis and time on the other. The data is displayed in the form of an image in which intensity, or colour, is used to represent amplitude(f,t).

The reason to have a Spectrogram is that it becomes possible to identify indiviudal sources/instruments based upon their frequency content and the way in which this changes in time (appears as a specific pattern/shape in the image). This is not possible with just a 1D spectrum (not enough degrees of freedom to uniquely identify a single source unambiquously).

Some interesting possibilities arise when using a Spectrogram - but it is likely to be very CPU hungry to do more than just display a Spectrogram.

texture · Post by **texture** » Mon Jun 21, 2004 9:59 pm

I'd have said a spectrum was 2d (freq and amplitude), and a spectrogram was 3d (freq and time and intesity).

The main reason I want one is for analysing aliasing.

Space Boy · Post by **Space Boy** » Tue Jun 22, 2004 6:31 am

texture wrote:I'd have said a spectrum was 2d (freq and amplitude), and a spectrogram was 3d (freq and time and intesity).

The main reason I want one is for analysing aliasing.

I'm from a medical imaging background where we talk about 1D, 2D, 3D and 4D images. In that context, a 2D image usually consists of 2 spatial axes and displays intensity(or amplitude or phase or velocity or etc.). That defines a digital image (rather like the monitor you are looking at). This is also considered to be a 2D image.

On a more fundamental note, since the intensity/amplitude can represent any physical property, it is not strictly considered to be a dimension (it is a scalar). Time is clearly a dimension and frequency is a derivative of time (units of 1/time) therefore frequency is also a dimension - hence 2D.

Miles1981 · Post by **Miles1981** » Tue Jun 22, 2004 7:51 am

Exactly - I'll have some medical imaging background in three years too, when my thesis will be finished

-

I have some other projects running concurrently - and paid, so it is biaised -, but as soon as I have a good vu-meter, the spectrogram will be very easy too do - because I would be able to display characters, lines, bitmaps efficiently, as well as have the backbone for storeing the samples. I have my idea for not having to recalculate a new bitmap at each redrawing... -

BTW, at first, there would be no visible parameters, only parameters that could be changed by the host by setParameter(), but if you have some parameters that you want to have, say it to me, I'll think of ot ;=)
And it would be stereo - the middle of the image would be 0Hz and the borders 20kHz -.

THK · Post by **THK** » Tue Jun 22, 2004 9:04 am

http://www.concretefx.com/QSpectrum.zip

Miles1981 · Post by **Miles1981** » Tue Jun 22, 2004 9:11 am

...
That's a spectrum analyzer, we need a spectrogram, it lack 1D

autloc · Post by **autloc** » Tue Jun 22, 2004 9:25 am

On a more fundamental note, since the intensity/amplitude can represent any physical property, it is not strictly considered to be a dimension (it is a scalar). Time is clearly a dimension and frequency is a derivative of time (units of 1/time) therefore frequency is also a dimension - hence 2D.

Not to be get too pedantic, but intensity, time and frequency are all scalars. A scalar need not be dimensionless; it must only be directionless (i.e., it can only represent a magnitude).

http://en.wikipedia.org/wiki/Scalar

I would assume that spectrograms are often called 2D because they are represented on 2D surfaces. Make the same thing out of computer printouts or clay as a topographical map, and no one could argue against it being actually 3D.

Miles1981 · Post by **Miles1981** » Tue Jun 22, 2004 9:29 am

Well, a waterfall is the same info displayed in a 3D box, but it's not actually 3D. A spectrogram is saved in a 2D table, so it is 2D. 3D images are for instance a set of 2D images but for a different depth in a patient - I take the medical example -, and 4D can be time - differents 3D sets at different time - or a set of patients.
Sound is 1D, but you can display it in 2D, and it will still remain a 1D data.

Spectrogram VST?