< Back to IRCAM Forum

Supervp - Gcross command

SuperVP for Max
#1

Hi, I am trying to use supervp gcross (from documentation) from command line:

cross type cross: S1 and S2 are calculated in amplitude/freq representation and the output is
	  Amp(SO) = Xval*Amp(S1) + xval*Amp(S2) +qval*(Amp(S1)*Amp(S2))^CE
	  Fre(SO) = Yval*Fre(S1) + yval*Fre(S2),

I am getting the error below. Am I missing a command option? Thanks!

supervp -S"file1.aiff" -s"file2.aif" -Gcross -A -Z "/output.aif" 

Initializing...

SuperVP::Parameter Error::checkpar::

Synthesis from sound data requested in track two: use either spectral data as input (see -isdata flag) or add analysis flag (see -A)

Done.
#2

Hello

I wrote in my mini intro that most of the commands have one input file and one output file. The -Gxxx operations are exceptions in that there are two inputs and one output. You’ve already found that you need an additional -s flag opening the second track with a corresponding file. Now you also need an additional analysis -a that adds the STFT analysis into the second (modulator) track. A general rule here is that the options that exist for both tracks use an upper case letters for the first (the main track) and a lower case letters for the second (the modulating) track. The mixing/modulating is taking place in the spectral domain so that from the two STFT spectra you create a single one that then enters the synthesis module (-Z). Therefore there is no lower case version of -Z.

You can see all modules that are configured to be used in the signal processing chain established by your command line together with the configuration options for the specific modules if you add -v to the command line.

Axel

#3

I see! By adding -a, I indeed had a successful execution of the command. However, my expectation was that the resultant file would contain some “characteristics” (amp/freq/phase) from both of the input files. I tried both Gadd and Gcross, but the output file sounded just like the first file (the one passed to -S). I wonder if I missed some more tweaking :thinking:

Thanks for bearing with my noob questions :slight_smile:

#4

Hello again

as you are interested in cross synthesis I have uploaded an old ‘tutorial’ written in the time of AS1. It explains cross synthesis in AudioSculpt1 with examples. For each example they give the settings in AS1 and the corresponding command line. supervp always tried to stay backwards compatible, so most of this should still work with the command line. The exception is the -J flag that selects a synthesis window.
The synthesis window is now always equal to the analysis window, so you need to remove the -J option
from those commands were there is one.

Here the link AS Cross documentation

Best

#5

However, my expectation was that the resultant file would contain some “characteristics” (amp/freq/phase) from both of the input files.

Indeed because you did not provide any mixing options to the modules.

  -G<cross-synthesis type> [-X<val>] [-x<val>]  [-Y<val>] [-y<val>] [-q<val>] ::   
 (Def.: X=1,x=0,Y=1,y=0,q=0)

The default mixing options are such that you preserve the first file (X=1, Y=1). I think after reading the doc I shared you will have a rather good idea how to approach this.

#6

Thanks for the prompt response! I will given these a try!

#7

The manual is definitely helpful, I had some synthesis going on :slight_smile:

I am ignoring this one, since it does not halt the execution of the command:
-J flag has been discontinued, will use analysis window instead

However, the error below is a show-stopper. I run into this one for several files that I use. Do I need to make sure that both files used in synthesis to have the same sampling rate?

Cannot find a Message for warn/error code <svp:srate_different> SuperVP::Parameter Error::svp::

svp:srate_different
#8

Also, it would be super useful if the cross synthesis files (which include the amp/freq per sound file) were included in the zip. The sound files used the manual are there but cross files are not unfortunately.

There is only one (“46crossfile-60”) and using it ends up with the error below. I tried removing the last column (which contains the q values) but it did not help.

Initializing...
-J flag has been discontinued, will use analysis window instead

*** WARNING: since LPC analysis has been requested on the secondary
	channel in mixer mode 'cross', the coefficients "x" and "y" will be zero 
Processing...

*** ERROR: cross synthesis of type cross can only handle
  input coding of type amplitude/frequency. 
  Please report this bug together with your SuperVP 
  parameters to IRCAM.

Done.
#9

Yes, both input files (-s and -S) need to have the same sample rate.

#10

Also, it would be super useful if the cross synthesis files (which include the amp/freq per sound file) were included in the zip. The sound files used the manual are there but cross files are not unfortunately.

Yep, sure, but these documents have been created 24 years ago, and they came to me a few years ago by circumstances I don’t quite remember. That’s all I have, sorry.

There is only one (“46crossfile-60”) and using it ends up with the error below. I tried rmoving the last column (which contains the q values) but it did not help.

You would need to send me the command line you use, otherwise I cannot tell you what the problem is.

Best
Axel

#11

Fair enough, thanks!