Sound files and pvf

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Hi,

On Mon, Dec 28, 1998 at 11:20:32AM -0500, Forrest Aldrich wrote:
> >Well, that's all there is :-(
> [ ... ]
> Understood, perhaps I can fix that :)

You're welcome.  Please talk to Griz (griz@coinet.com) about that, he's
doing the voice documentation stuff.

> >You might want to use ADPCM-4 for best results (pvftormd ZyXEL 4 ...).
> [ ... ]
> 
> I recall, back in the days where I had a 3b1, that 8000 samples was very good,
> but that was in ulaw format.   So, it must be a problem with the software I'm
> using
> (CoolEditPro and sox).  Though I did try recording a song from CD->WAV into
> 8000
> samples, and it sounded just horrible.  I'm presuming I'm doing something
> wrong.

Try converting to wav/mono/44100 (CD sampling rate) with SOX, then to
PVF (portable voice format) with "wavtopvf", changing the sampling rate
with "pvfspeed 9600" (or so), and then converting to the ZyXEL modem
data format with "pvftormd".

I'm not sure whether I remember that correctly, but I think pfvspeed
does sample interpolation and sox does not, so certian speed conversions
sounded just horrible with sox.

> I'm not a sound engineer :)
> 
> So, the original files I have are in *.WAV or *.RAW format, and at very high
> resolution
> (44100).   So, the path to to an *.rmd file format is:
> 
>         wavtopvf | pvftormd ZyXEL 4

Make this:

  cat <rate-44100-file-*MONO*> |wavtopvf | pvfspeed ... | pvftormd ...

[..]
> Have you any recommendation of sound manipulation software?

Actually, no.  I use "sox" and Sun's "audiotool", but I don't do much
sound stuff anyway - I'm more the fax/data guy.

gert
-- 
Gert Doering
Mobile communications ... right now writing from *AWAY* :-)) 
... mobile phone: +49 177 2160221 ... or mail me:  gert@greenie.muc.de