World: r3wp

unfortunately there's missing page 2 in the document. however if 
anybody is interested in synthesis, next version of sintezar is going 
to have five different oscilators, four filters, three waveshapers 
(these units are ready now) plus some other units (phaser is ready, 
i'm working on delay). I wrote some basic sequencer last week, so 
only some preset management system is missing and some work on GUI 
(drag and drop for connecting modules is ready, but I still have 
to rewrite all modules to support it)

Sounds good Kru, would like to look at it when you're ready.

Antor if you're interested, here's a screenshot of work in progress 
- http://krutek.info/pix/sintezar.jpg

Very nice looking ! May I criticise your knobs though ? They are 
a bit big. Before long, you won't have any room left ! :) I suggest 
make them half the size in width and height.

But very good. Inspirational, indeed.

i love those fancy bars from winamp or wmp how they do that ? how 
they get the khz and hz and all that from the wav file ? suposing 
it is a wav ... (raw or pcm)

fast fourier transformation. no way in current rebol (to much computations). 
On my Athlon XP 1700+ can REBOL do some 3milions computations in 
second (this is very aproximate number, some computaions are more 
time-consuming than other ). May sound like a big number, but if 
sound's sample rate is 44100Hz, there's only some 70 computations 
for each sample. And this is the ideal situation (no GUI and other 
CPU-demanding stuff). So there are two possibilities. 1) Some faster 
math, or JIT REBOL compiler  and 2) wait for faster CPU's. Let's 
see what comes first.

(He he he....)

first comes faster CPUs :-) What about producing language extension? 
Ah, we did not get any yet, sorry, I forgot, it is long time we were 
promissed to get those ;-) Hmm, but what about external library calls? 
Could do the trick, no? If you use gcc, you should be able to compile 
for main platforms at least ...

JIT (VM) for some specific tasks could be sufficient too, but we 
can only hope here. The only realistical thing is to use what we 
have now - other tool than REBOL ;-), or library calls ....

Pekr yes, external library call can solve it (partially). I have 
to install some C/C++ SDK and start to learn it again...

I worked with image data in external library, was not all that difficult. 
Forget C ++, use C. But then - image data is just repetitive pattern 
of RGBA values, so maybe working with sound data will be much more 
difficult ...

Can you write prototype in rebol, and i try my c-skills?

sorry, what prototype?

Syntezar's?

that needed c-part, fft.

i don't know the math, but i may be able to translate rebol to c.

there's fft C library, http://www.fftw.org/

so you only need stubs?

but I haven't tried it yet.

No I probably have to rewrite all my routines to C. I haven't started 
working on FFT at all.

I've got phase-distortion oscillator, FM oscillator, wavetable oscillator 
and my exponential oscillaor plus four types of filters and it's 
really time consuming in REBOL

Can i try t translate that?

That should be great

Where to start?

you can try this Phase Distortion I wrote yesterday

where do i find it?

osc: context [
	phase: 0
	AM: 1				;Amplitude modulation
	PWM: 0.5		;Pulse width modulation
	DCW: .5	; phase transition between sine and other wave [0 - 1]

 wave-length: 400	;wave-length is sample-rate / frequency - don't 
 wanna have samplerate here	
	algorithms: [
		saw [
			d: (1 - dcw) / 2
			cosine 360 * switch-range ph [
				0 d [ph * (pwm / d)]
				d 1 [(ph - d / (1  - d)) * pwm + pwm]
			]
		]
		square [
			d: 1 / max 1e-50 (1 - dcw)
			cosine 360 * switch-range ph reduce [
				0 .25 [ph * 4 ** d / 4]
				.25 .5 [(abs ph - .5) * 4 ** d / 4 + .5]
				.5 .75 [ph * 4 - 2 ** d / 4 + .5]
				.75 1 [(abs ph - 1) * 4 ** d / 4 + 1]
			]
		]
				
		triangle [
		;triangle is d~.588888
			d: 1 - (dcw * .41111) ;1 / max 1e-50 (1 - dcw)
			cosine 360 * switch-range ph reduce [
				0 .25 [ph * 4 ** d / 4]
				.25 .5 [(abs ph - .5) * 4 ** d / 4 + .5]
				.5 .75 [ph * 4 - 2 ** d / 4 + .5]
				.75 1 [(abs ph - 1) * 4 ** d / 4 + 1]
			]
		]
	]
	algorithm: 'saw
	curves: copy []
	forskip algorithms 2 [append curves to string! algorithms/1]
	phaser: func [][
		phase-per-byte: 1 / wave-length
		phase: phase + phase-per-byte
		if phase > 1 [phase: phase - 1]
		phase
	]
	wave: func [
	][
		ph: phaser
		do select algorithms algorithm
	]

right here ')

Thats the right size to refresh my knowledge :)

PWM should be always 0.5 (it's from some older version)

it supprots three different waveform (still six missing to recreate 
my CasioCZ ;)

basics are 'phaser function - updates oscillator phase

and wave function - produces actual sound

with DCW you control shape of waveform. DCW-0 is sine waveform, DCW-1 
is (square, saw, triangle)

where does switch-range come from?

it's just support function

switch-range: func [number blk][
	foreach [rfrom rto action] blk [
		if not number? rfrom [rfrom: get rfrom]
		if not number? rto [rto: get rto]
		if all [number >= rfrom number < rto][return do action]
	]
]

Is there a loop around that?

yes there's a loop

I'm filling a buffer of 256 bytes so I can change parametres in realtime 
(buffer is filled, GUI works again, I can fiddle with knobs) and 
then I add buffer's content to some sound [block!]

buffer: context [
	length: 256
	data: make block! length
	init: does [
		data: make block! length
	]
	fill: func [fnc][
		init
		loop length [
			insert tail data do fnc
			data
		]
	]
]

then just >>insert tail sound buffer/data

but because there's no difference in speed of integer and FP math 
in REBOL, everything is done in FP sou it's needed to convert FP 
to 16-bit integer

sou=so

math with fpu should be comparable in speed today. i try it.

I'm using this code (and I really hope there's some better solution): 
>> insert tail sample do rejoin ["#{" skip to-hex to integer! (sample-value 
+ 1) * 32767.5 4 "}"]

If floating point is fast enough today, it's better to use FP because 
of resolution

I know Rebol quite well but I don't know music. Can anybody point 
me to a white paper/tutorial/newbie docs/samples that explains how 
to valorize sound/data to play some notes? Thank you.

luca: take a look at http://www.rebol.com/docs/sound.html, it's 
googd start. there are examples how to synthetize simple sine wavew 
and how to apply some envelope on it.