October 28th, 2010
Cialis angioplasty After having Tonfall released, cialis angioplasty I think it might be a good idea to go a bit deeper into some audio-dsp subjects. Cialis angioplasty The easiest way to create a sound is by creating a wave out of an algorithm. Cialis angioplasty You usually take a normalized variable between zero and one as the phase and pass it to a function. Cialis angioplasty The phase itself must be incremented every sample by the following expression.
phase += frequency / samplingRate;
phase -= int( phase ); // [0, cialis angioplasty1]
Cialis angioplasty amplitude = waveshaper( phase ); // [-1, cialis angioplasty+1]
Cialis angioplasty Tonfall provides wave-shaping function like sinus, cialis angioplasty triangle, cialis angioplasty sawtooth and pulse (rectangle). Cialis angioplasty The last one is well known by me from the C64 sound-chip and provided setting the pulse width. Cialis angioplasty A normal pulse wave is 1.0 for all phase value lower than 0.5 and -1.0 for the rest of the phases. Cialis angioplasty If you modulate the center (0.5) back and forth, cialis angioplasty the sound gets more wide and living. Cialis angioplasty This is called Pulse-modulation but also reflects to phase-modulation. Cialis angioplasty The effect on this simple waveform is the same.
Cialis angioplasty For Audiotools Pulverisateur we wanted to implement such modulations for all kinds of waveshapes, cialis angioplasty even curves. Cialis angioplasty So I needed to find a good and fast way to translate the phase value into a modulated value that could be passed into the wave-function.
amplitude = waveshaper( modulate( phase ) ); // [-1, cialis angioplasty+1]
Cialis angioplasty These were the requirements
- Receive a value between zero and one and return a value between zero and one
- Ability to bend the value in both directions (symmetric)
- Be able to remain the input
Cialis angioplasty Lets see what I came up with
Cialis angioplasty The best part is, cialis angioplasty that there a parameter t to shape the curve. Cialis angioplasty The upper curve (t>0) extends the output value and it compresses it later. Cialis angioplasty The lower(t<0) is exactly doing the opposite. Cialis angioplasty It is symmetric to y=x. Cialis angioplasty Lets compare some values of t.
Cialis angioplasty t: +/- 2
Cialis angioplasty t: +/- 1
Cialis angioplasty t: 0
Cialis angioplasty That is another benefit. Cialis angioplasty When you pass t=0, cialis angioplasty you get a straight line.
Meaning: output = input
Cialis angioplasty t: +/-64
For really high values for t towards INFINITY you get in the end a right angle.
Cialis angioplasty Costs
Curves like that are usually very expensive. Cialis angioplasty I stumbled upon Super Ellipse, cialis angioplasty which distracted me for a couple of hours. Cialis angioplasty It uses exponential functions, cialis angioplasty which I cannot run on every sample at 44100 Hz. Cialis angioplasty I thought about taking a quadric bezier curve, cialis angioplasty but transforming the function to x leads to a sqrt-root. Cialis angioplasty This solution presented here costs just one division and some simple algebra, cialis angioplasty which is okay for audio-dsp. Cialis angioplasty I don't know, cialis angioplasty if I invented this thing. Cialis angioplasty If you know, cialis angioplasty what it is, cialis angioplasty let me know!
Cialis angioplasty Phase modulated sinus-wave
Cialis angioplasty Function (for positive t)
Cialis angioplasty Function (for negative t)
Cialis angioplasty Actionscript
private function bend( x: Number, cialis angioplasty t: Number ): Number
if( t < 0.0 )
return x / ( t * x - t + 1.0 );
var tx: Number = t * x;
return ( tx + x ) / ( tx + 1.0 );
Cialis angioplasty If you want to listen to the implementation, cialis angioplasty check out Audiotool, cialis angioplasty launch the application and create a Pulverisateur. Cialis angioplasty Make sure to init the default patch and start with a single oscillator. Cialis angioplasty Hope you like it!
Cialis angioplasty Or just open a template I made on Audiotool.com
Filed under: audio dsp
11 Responses to “Female Viagra Response”
Tweets that mention Andre Michelle » Blog Archive » Phase Modulation -- Topsy.com Says:
October 28th, 2010 at 6:06 pm
[...] This post was mentioned on Twitter by Andre Michelle and Nicklaus Hubben, Daniel Ruiz. Daniel Ruiz said: @9nto :P RT @andremichelle: Blogpost: Phase Modulation (AudioDSP) – http://tinyurl.com/as3-phasemod [...]
October 28th, 2010 at 6:37 pm
Hey Andre! Great post, would you be able to create a demo in Audiotool showing Pulverisateur in action? Couldn’t find it anywhere in the modules in the right drawer.
Andre Michelle Says:
October 28th, 2010 at 6:42 pm
Done the same time while you typed. Check out last link.
October 28th, 2010 at 6:52 pm
I’m not sure if a name for what you’ve described already exists, but it is very cool. Thanks for posting your insights. Looking forward to reading more DSP related articles!
Irek Khasyanov Says:
October 28th, 2010 at 7:40 pm
Thanks for sharing, Andre!
I have two questions about tonfall:
1) how to use BiQuadFilter? I need to implement processor for it or no?
2) how to deal with 2 sounds, if I want to use different processors on them?
Andre Michelle Says:
October 28th, 2010 at 8:28 pm
1) You can pass a Signal of the SignalBuffer and it runs the filter over the next pointers.
2) Check out the ToneMatrix in Tonfall. It runs a polyphonic synthesizer. Different processors are only useful when generating or processing different stuff.
Steve Bloom Says:
November 15th, 2010 at 12:19 pm
Well done to Petter Solberg for coming a thrilling 2nd in the Wales Rally GB 2010 – bit slidey though!
February 25th, 2011 at 11:32 am
There is discontinuity in first derivative… :/
erik eide Says:
October 9th, 2012 at 11:23 pm
hi, nice work!
like @Itek, =Id like to use the BiQuad to manage a LowPass, but it stays very obscure to me
could u be a bit more explicit on it please ?
at least, explain parameters u pass to the public function and how I inject this in the mixerUnit ?
November 13th, 2012 at 8:36 pm
how can ı do that ı dont know can you help me about it if you want to help me pls send me e mail
Evden Eve Nakliyat Kayseri Says:
November 13th, 2012 at 8:37 pm
we can do everything from kayseri kayseri is so pretty city in anatolia u can visit kayseri