Re: [Audacity-nyquist] Nyquist trouble saving sound file

[David R. S. <sk...@wa...>]

On Mon, 29 Nov 2004, Eivind L. Rygge wrote:

> I am trying to write an audacity plugin in Nyquist, I use the nyquist
> prompt for the development.

It isn't clear to me - what are you trying to do with your plug-in?


> I have borrowed some code from the Nyquist manual (the DSP 
chapter), the
> code is as follows (never mind that it returns a sound with only zeros, at
> least then I know it's working...):
>
> ;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
> ;nyquist plug-in
> ;version 1
> ;type process
> ;name "Wav-fix (test)"
> ;action "Calculating delta values in waveform"
>
> (setf subtract-class (send class :new '(s1 s2)))
>
> (send subtract-class :answer :next '()
>      '((let ((f1 (snd-fetch s1))
>              (f2 (snd-fetch s2)))
>          (cond ((and f1 f2)
>                 (- f1 f2))
>                (t nil)))))
>
> (send subtract-class :answer :isnew '(p1 p2)
>      '((setf s1 (snd-copy p1))
>        (setf s1 (snd-copy p1))))
>
> (defun snd-subtract (s1 s2)
>  (let (obj)
>    (setf obj (send subtract-class :new s1 s2))
>    (snd-fromobject (snd-t0 s1) (snd-srate s1) obj)))
>
> I then try to load this file (wav-fix3.ny) and use it on a stereo wav-file:
>
> eivind@lennart:~$ ny
> XLISP version 2.0, Copyright (c) 1986, by David Betz
> CMU MIDI Toolkit, Copyright (c) 1993,1994, by Roger B. Dannenberg
> ; loading "/usr/share/nyquist/runtime/init.lsp"
> ; loading "/usr/share/nyquist/runtime/nyinit.lsp"
> ; loading "/usr/share/nyquist/runtime/fileio.lsp"
> AutoNorm feature is on.
> ; loading "/usr/share/nyquist/runtime/follow.lsp"
> Default sound file is eivind-temp.wav.
> system.lsp : *RUNTIME-PATH* = /usr/share/nyquist/runtime/
>
> Nyquist -- A Language for Sound Synthesis and Composition
>    Copyright (c) 1991,1992,1995 by Roger B. Dannenberg
>    Version 2.29
>
>> (load "/home/eivind/src/eivind/wav-fix/trunk/wav-fix3.ny")
> ; loading "/home/eivind/src/eivind/wav-fix/trunk/wav-fix3.ny"
> [ gc: total 16640, 402 free; samples 1KB, 0KB free ]
> T
>> (setf my-snd (s-read
> "/home/eivind/src/eivind/wav-fix/trunk/MozartKons_part2_pcm32.wav"))
> #(#<Sound: #401ee348> #<Sound: #401ee7e0>)
>> (setf my-snd3 (snd-copy (aref my-snd 0)))
> #<Sound: #401ee848>
>> (setf my-snd3 (snd-copy (aref my-snd 0)))
> #<Sound: #401ee898>
>> (setf new-snd (snd-subtract my-snd2 my-snd3))
> #<Sound: #401ee9d0>
>> (s-save new-snd 100000000 "./testfil2.wav")
> Saving sound file to ./testfil2.wav
> error: bad argument type - NIL
> 1> (s-save new-snd 100000000 "./testfil2.wav")
> Saving sound file to ./testfil2.wav
> SND_get_first returned 0 samples
> snd_list info: 401eea20 allocated by snd_list_create, seq_num 35
> block info: 401eeaa0 allocated by fromobject__fetch, seq_num 38
> SOUND PRINT TREE of 401f1ad0
> sound_type@401f1ad0(SND_get_first@809d040)t0 0 stop 2147483647 sr 96000
> lsc -1030 scale 1 pc 0->snd_list@401\
> eea20 (skipping 1) ->
>  susp@401ee988(fromobject)toss_cnt 0 current 0 lsc -1030 sr 96000 t0 0
> 401eea88
> It is possible that you created a recursive sound
> using something like: (SETF X (SEQ (SOUND X) ...))
> Nyquist aborts from non-recoverable error
> /usr/bin/ny: line 6: 31570 Avbrutt (SIGABRT)
> XLISPPATH=/usr/share/nyquist/runtime:/usr/share/nyquist/l\
> ib /usr/bin/ny.bin
> eivind@lennart:~$
>
> So there.  I am a bit stuck.  What is the NIL it is complaining about the
> first time I use s-save?  And why does it crash the second time?
>
> Hope the lines are formatted ok (I guess I will know when I get the email
> from the list...)
>
> Eivind
>

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