PEVocoder is based on open source code from the Zerius Vocoder 1.2 by Emanuel Borsboom. You can download information,original C source code, and command line versions for a variety of platforms from Zerius:
http://zerius.com/vocoder/
ftp://ftp.zerius.com/pub/zerius/vocoder/
PEVocoder 1.0 is a REALbasic plugin that provides vocoding capabilties through one global Method:
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The Method:
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PEVocode
(
modulatorpath as string,
carrierpath as string,
targetpath as string,
windowlength as integer,
windowoverlap as integer,
bandcount as integer
)
as Integer
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The Parameters:
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modulatorpath as string - the file path for the sound file to be used as the modulator. For example, use m.absolutepath, where m is a REALbasic FolderItem representing the modulator audio file. The modulator sound file must be MONO, 8- or 16-bit linear, uncompressed AIFF or WAVE file.
carrierpath as string - the file path for the sound file to be used as the carrier. For example, use c.absolutepath, where c is a REALbasic FolderItem representing the carrier sound file. The carrier sound file must be MONO, 8- or 16-bit linear, uncompressed AIFF or WAVE file.
targetpath as string - the file path for the resulting sound file you wish to create. For example, use t.absolutepath, where t is a REALbasic FolderItem representing the target sound file. The resulting sound file will have the same file type as the modulator (regardless of the file extension you give it).
windowlength as integer - the number of samples that will be analyzed at a time, and must be a power of two (defaults to about 1/15th of a second worth of
samples). If you pass it a value of -1, the plugin will use the default value. (Recommended, if you don't know what you're doing.)
windowoverlap as integer - the number of samples that the windows will be overlapped (defaults to one half of the window-length). If you pass it a value of -1, the plugin will use the default value. (Recommended, if you don't know what you're doing.)
bandcount as integer - the number of frequency bands that the carrier will be modulated with (defaults to 16). If you pass it a value of -1, the plugin will use the default value. (Recommended, if you don't know what you're doing.)
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The Return value:
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PEVocode returns an integer upon completion. If the vocoding operation is successful, the Method returns a value of 1. If there is an error during processing, PEVocode returns one of the following error codes:
ERROR Code: What it means:
-10 winlength must be >1 and also a power of 2 [e.g. 128,256,512,1024,etc...]
-11 winoverlap must be >=0 and <=(winlength/2)
-12 bandcount must be >0 and <=(winlength/2)
-13 carrier audio file must only have 1 channel (Mono)
-14 modulator audio file must only have 1 channel (Mono)
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Copyright
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The Zerius Vocoder is Copyright (C) 1996-1998 Emanuel Borsboom.
SampleModulator.aif and SampleCarrier.aif sound files courtesy Emanuel Borsboom.
The FFT code (contained in fftn.c, fftaux.c, fft.h, and spt.h) is
Copyright (C) 1993 Steven Trainoff.
The code for converting to and from IEEE floating-point numbers is
Copyright (C) 1988-1991 Apple Computer Inc.
You are free to do whatever you like with the vocoder, as long as the
copyright notice stays intact and you note any changes.
