Re: [Audacity-nyquist] A Variable-shape, multi-track cross-fade.

[Leland <le...@au...>]

Steve wrote:
> On Sun, 2009-09-20 at 13:04 -0500, Leland wrote:
>> Dave Storer wrote:
>>> The interface between Audacity and Nyquist implements multiple track 
>>> operations by simply calling the plug-in once for each selected track 
>>> with the same set of arguments for each call.   Unfortunately, there 
>>> seems to be no way to carry over any information from one call to the 
>>> next except by saving the state information in an external file.
>> Dave,
>>
>> There's a global variable called *SCRATCH* that can be used for this 
>> purpose.  It is not restored between between tracks.
>>
>> Leland
> 
> That's fantastic! Suddenly a plug-in that I wanted to make becomes
> possible.
> 
> Is *SCRATCH* a new feature specific to Audacity? I've seen no
> documentation about it whatsoever.

Yes, it is Audacity only since, AFAIK, Audacity is the only app that 
uses Nyquist as a library.  It was added when I upgrade the Nyquist 
version in Audacity at the beginning of the year.

> 
> Any other undocumented features that you know of?
> 
A couple of new comment statements were added when I did the upgrade.

;codetype lisp | sal

Tells Audacity the syntax to expect and how to pass it on to libnyquist. 
  The default is lisp.  Only one type is allowed.

;debugflags trace | notrace | compiler | nocompiler

Trace and notrace simply set Nyquist's "*tracenable*" global.  This is 
similar to clicking the Debug button in the Nyquist prompt, but it 
allows the plug-in to control it instead.

Compiler and nocompiler controls whether the generated Lisp code from 
the SAL compiler will be sent to stdout or to the output window in the 
Nyquist Workbench.

> Is Audacity now using Nyquist Version 3.02?
> 
It's at 3.03.

> It appears that SAL is now available, though I've not been able to do
> anything useful with it (other than lock up Audacity). Is there any
> information about using SAL in Audacity?
No documentation.  I was sort of hoping Edgar might add it to his nice 
Nyquist site.  :-)

> Are there any advantages to
> using SAL?
> 
Much easier to grok for us Lisp challenged ppl.  :-)


Leland