W3C home > Mailing lists > Public > public-audio@w3.org > October to December 2012

Re: Phase offset for OscillatorNodes?

From: redman <redman@redman.demon.nl>
Date: Tue, 27 Nov 2012 00:29:24 +0100
Message-ID: <50B3FB54.4060204@redman.demon.nl>
To: public-audio@w3.org
On 26-Nov-12 21:27, Chris Rogers wrote:
> On Mon, Nov 26, 2012 at 2:43 AM, Jussi Kalliokoski<
> jussi.kalliokoski@gmail.com>  wrote:
>> On Mon, Nov 26, 2012 at 6:32 AM, Chris Rogers<crogers@google.com>  wrote:
>>> On Sat, Nov 24, 2012 at 7:01 AM, Patrick Borgeat<
>>> patrick.borgeat@gmail.com>  wrote:
>>>> Hi there,
>>>> I wonder if OscillatorNodes could have some kind of phase offset (or
>>>> maybe I'm missing something and there is such thing?)
>>>> Here's an example how the phase parameter in SuperCollider affects the
>>>> signal:
>>>> [image: Inline-Bild 3]
>>>> [image: Inline-Bild 4]
>>>> Phase offsets are pretty important for LFOs. I also use them for drum
>>>> synthesis (to have a nice click at the beginning).
>>>> A phase offset could be passed as an optional double offset=0 parameter
>>>> to the start method of OscillatorNodes. A modulateable phase parameter
>>>> could be interesting as well off course, but might be overkill for the Web
>>>> Audio API.
>>>> Looking forward reading your thoughts on that :-).
>>> Hi Patrick, in addition to an optional argument as you suggest, we might
>>> consider a .phase attribute which is an AudioParam.  We can already get
>>> many FM effects since the .frequency attribute is pretty flexible.  But
>>> maybe .phase as an AudioParam would also be worthwhile.
>> Is that phase as in phase offset? Phase offset might be more useful, but
>> admittedly you might be able to create pretty interesting stuff with phase
>> modulation, although it sort of overlaps with the waveshaper node.
> Yeah, .phaseOffset is really what it needs to be I think.  This would be
> additive with the cummulative phase from .frequency (and .detune).  This
> seems nice since if you set .frequency to 0, then there would be no
> cummulative phase and you could control the phase directly with
> .phaseOffset.  How does that sound?
Sounds like Yamaha!

(i just assume everyone knows that the Yamaha implementation of FM (DX7 
etc.) was in fact phase modulation as described above).
Received on Monday, 26 November 2012 23:29:55 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 19:03:14 UTC