As an example, a Federal Signal SD-10 siren consists of two tones, 515 Hz and
690 Hz. Usually, the wind-ups start at 0 Hz and then go up to the constant
tone, then the wind-downs go from the constant tone back down to 0.
-----Original Message-----
From: audacity4blind-bounce@xxxxxxxxxxxxx
[mailto:audacity4blind-bounce@xxxxxxxxxxxxx] On Behalf Of Robert Hänggi
Sent: Friday, January 13, 2017 6:43 AM
To: audacity4blind@xxxxxxxxxxxxx
Subject: [audacity4blind] Re: Making Plugin Codes
2017-01-13 13:26 GMT+01:00, Steve the Fiddle <stevethefiddle@xxxxxxxxx>:
One solution, and I'm sure I've suggested this before, is to generateThis approach might be tricky, it depends on the desired frequencies.
a constant HQ tone, then use the "Sliding Time Scale / Pitch Shift"
effect to turn it into a sliding pitch tone (a "chirp").
Steve
On 13 January 2017 at 12:16, Robert Hänggi <aarjay.robert@xxxxxxxxx> wrote:
Hi Annabelle
This isn't easy to do because Steve's code builds a table (one cycle)
with the individual harmonics added.
This table could theoretically be applied to a chirp.
However, the problem is that the number of harmonics change with the
rise and fall of the frequency:
Chirp 200 to 10000
Harmonics 100 down to 1
Thus, I would take a different approach with oversampling:
- add new track
- track drop down menu (shift+m) -->rate-->other
- enter the new sample rate 1000000 (approx 23 x oversampling)
- create the chirp
- track menu-->resample 44100 (or whatever you want)
I hope this is sufficient until Steve may have another proposal.
Robert
2017-01-13 1:03 GMT+01:00, Annabelle Susan Morison
<foristnights@xxxxxxxxxxx>:
Hi, it's Annabelle.
How would I make the code for a plugin that can generate chirps without
aliasing distortion? That is, a chirp generator based on the HQ Tone
Generator?
The audacity4blind web site is at
//www.freelists.org/webpage/audacity4blind
Subscribe and unsubscribe information, message archives,
Audacity keyboard commands, and more...
To unsubscribe from audacity4blind, send an email to
audacity4blind-request@xxxxxxxxxxxxx
with subject line
unsubscribe
The audacity4blind web site is at
//www.freelists.org/webpage/audacity4blind
Subscribe and unsubscribe information, message archives,
Audacity keyboard commands, and more...
To unsubscribe from audacity4blind, send an email to
audacity4blind-request@xxxxxxxxxxxxx
with subject line
unsubscribe