[Bradford] Convert wave amplitude into a float

[Nick Rhodes]

I think Dave is right,

I guess they are going to be doing frequency-amplitude analysis, which is
commonly done by Fast Furiour Transforming samples into groups of
frequency-amplitude (think graphic equaliser). FFT is much easier to
program with floating point samples.


On 20 March 2014 20:49, John R. Hudson <j.r.hudson at virginmedia.com> wrote:

> Thanks for all the suggestions which I will pass on if they haven't
> joined the mailing list yet. Because they want to do it continuously,
> reading the Alsa PCM device seems the most likely route. But maybe one
> of the other options will be more useful for them once they investigate
> them.
>
> However, thanks for the suggestion about how to export from Audacity as
> that will enable them to use the data they have already collected to
> develop the software before they need to apply to an actual stream.
>
> John
> --
> On Thu, 2014-03-20 at 20:25 +0000, David Spencer wrote:
> > What they *really* want to do is probably some kind of realtime signal
> > processing... which is not what Audacity is for (it's an editor).
> > They should probably be looking at reading the Alsa pcm device
> > directly (e.g. from Python); I bet that's what is pencilled in to
> > consume these hypothetical floats... either that, or the hypothetical
> > float-consumer needs to read an arbitrary well-understood audio file
> > container (e.g. WAV) using a library routine. Once the ints are in a
> > program, It's not rocket science to convert ints to floats prior to
> > feeding them to whatever other library routines are processing the
> > data (fft or whatever).
> >
> > The audacity question as posed just sounds like they caught the first
> > bus that came along :-)
> >
> > -D.
> >
> >
> > On 20 March 2014 17:46, John R. Hudson <j.r.hudson at virginmedia.com>
> wrote:
> > > Hi
> > >
> > > I popped in to see Paul Cannon this afternoon and they had just hit a
> > > problem - how to convert a wave amplitude as displayed in Audacity into
> > > a float which can be fed into another program.
> > >
> > > There is no obvious way in which to do this from Audacity. So it may
> > > involve using different software.
> > >
> > > Any thoughts very welcome.
> > >
> > > John
> > > --
> > >
> > >
> > >
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>
>
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