Scratching (With Dj Hero Controller) - groove~ or phasor~?

gavspav's icon

Hi I've been working on an installation where you can talk into a mic/webcam and then scratch yourself.
If you're interested there is a bit of video towards the end of this clip:
http://www.youtube.com/watch?v=Yn4XvuOPE8w

I originally made it using Ms Pinky and MaxforLive but then realized I didnt really want to expose my turntable/vinyl and needle to the festival massive.
I considered using a cd deck, particularly the numark cdx as it has a spinning platter and is meant to feel similar to vinyl but tales of unreliability put me off and it seemed a bit like overkill anyway.

So I've settled on the dj hero controller which gives a velocity value for the rotation of platter. Its plasticky as hell but the turntable bit feels surprisingly good.

I was initially using a phasor~/rate~ based system with index~, play~, wave~ (tried all 3) but now I think groove~ sounds as good if not better.
Its also much simpler.

Here's a basic patch with my two methods. Currently sending MidiCC from Osculator on 22. havent experimented with wii externals yet.

Just wondering if anyone has any experience of simulated scratching - any comments or ideas of how I could improve the way it sounds.

Max Patch
Copy patch and select New From Clipboard in Max.

If anyone wants to know anything about the controller ask away.

gavspav's icon

Just realized I put this in the M4L forum by mistake.Sorry - any chance of moving across to Max?

pixelmechanic's icon

Hey Gav,

Been following yr exploits from afar post AV Lab!

Very interested in this! From your comments I guess you bought the Wii version of the controller?

How many controllers does it spit out? Is each button different number (plus xfader etc.)?

I guess it would work with other formats too...

BTW, lol'ed over scalextric video glasses!

Cheers,

Jules

gavspav's icon

Oh hiya.
Yeah its the wii version but thinking of changing to a PS2 one cos its using up a wiimote.
All the controllers are wireless apparently but there do exist some wired ones for demo purposes.
I dont trust wireless stuff really.

I've only had it a couple of days. I've been using osculator and it seems to spit out values for everything but in slightly strange format.

eg Platter returns 0-1 for forward motion and 1-0 for backwards motion. So values overlap and need a bit of processing.

The crossfader here seems to only give values for half of its travel.

I got it cos the turntable felt quite good but the other controls are truly awful in anycase. I'm gonna replace them with arcade controls and a real crossfader probably for finished installation.

pixelmechanic's icon

By 0-1, do you mean 0 to 1 e.g. a float based on amount of rotation?

Cheers, J

gavspav's icon

Yeah sorry I wasn't very clear.

It is actually Osculator that is creating those values anyway and they depend on which output format you choose.

I'm not sure how to read the raw bluetooth data that Osculator is receiving. I should checkout the wiimote externals for max at some point.

The data isnt based on the amount of rotation but on the speed of rotation.
With normal use it is between and 0 and 0.5 for forward motion and between 1 and 0.5 for reverse motion.
But if you spin it really quickly the values overlap.
Either that or the sensor just gets confused. Not sure yet.

It uses a quadrature system which is a bit like a ball mouse.

And what do you think - given that the data I have is speed of rotation, any disadvantage to using Groove~?

pixelmechanic's icon

Cheers for info... can't think of any reason not to use groove~

J

gavspav's icon

Just got my hands on a ps3 dhero controller.

I cant believe the turntable controller is different but it does spit out a narrower range of values and possibly at a different rate.

So far the scratching effect sounds much worse with the ps3 version.

Which is a shame as the values it spits out are alot more straightforward.

pedrodevoto's icon

Hi. I'm trying to create a scratch simulating patch. I will not use it (at least for now) with an external controller.

I use Max 4, so I couldn't check out your patch... anyway, I was wondering if I was in the right direction; you said you are using groove~, so basically you would need to input a rate value. As far as I understood, your DJ controller outputs a rate/speed value, not a position value; right?

I'm using the "dial" object to simulate the turntable, so it is getting quite difficult to convert the output of the dial into a rate value.

Any comments would be appreciated.

best!

seejayjames's icon

"I'm using the "dial" object to simulate the turntable, so it is getting quite difficult to convert the output of the dial into a rate value."

Look at the [scale] or [zmap] objects, they will do conversion from the dial's 0-127 integer values into ones better-suited for the sig~ rate (like -1.5 to 1.5 or something). Super-handy in all kinds of data-scaling situations.

Jagle's icon

had a looka t your patch using my wiimote version of the DJ hero, and what i think yuo wanna do is first off split the values so 1-64 are isolated and 65-127 are, that wa you send send and scale these vales to effect the playback speed.

lets say from trial and error i know anything playedback at more then -5 into the groove sounds like crap i could scale my 65 to 127 to 0 to -5, and simillarly 0-64 to 0 to 5 for playing forward speed, need to go try it out but i reckon that might give you more control, also then the 3 buttons red green and blue can select different varriable of playback scratching heaven

gavspav's icon

Back on this now after getting oh so close to getting an installation ready for summer season of festival fun.

What I was finding with the Wii version was that although motion in one direction would give values of 1-64, occasionally it would throw in a value between 65 and 127.

I could of course have discounted odd values but it would've meant losing responsiveness.

The PS3 version spits seems to spit out more reliable values. It does have a sleep mode though which is a minor irritation.

Also I couldn't get 2 decks working with the Wii version but this doesnt seem to be an issue with the PS3.

So PS3 seems the way to go.

I've just had a look at the patch I put together before the summer and I was quite impressed! 2 decks of webcam scratching with effects.

A bit buggy though - I'll tidy it up and make a video soon [yeah right].