A blog about software – researching it, developing it, and contemplating its future.

Goodbye XNA, helloooo SharpDX

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Half a year ago I posted about my XNA dilemma, and about how SharpDX looked like the best replacement. XNA = old and busted C# DirectX library from Microsoft, now officially kicked to the curb; SharpDX = amazing generated-from-C++-DirectX-sources open source C# binding to the entire DirectX API, which is waaaaay more than XNA ever did.

Last summer I was a bit daunted by SharpDX, as the API was not very XNA-like. Alex Mutel, the primary author of SharpDX, said he was working on an XNA compatibility layer but it wasn’t ready yet. I then figured out how to get multiple window support (the primary driver at the time) working with XNA, so I set SharpDX aside for a while.

Well, Alex was as good as his word. After a fair amount of very entertaining Holofunking over the holidays (Holidayofunking?), I finally decided that with the new year would come a new 3D library underneath Holofunk. And what do you know, the SharpDX Toolkit library was ready.

Over the course of a couple of weeks, working relatively infrequently and in small chunks, I converted everything off of XNA. If you want to see a reasonably small, but realistic, XNA-to-SharpDX conversion in full, you could do a lot worse than looking at this changelist on CodePlex.

First of all I realized there was no multi-window support in SharpDX. Well, that’s fine, I posted an issue about it and offered to help with the implementation. Alex immediately responded and asked for a short while to build some support pieces. The next thing I knew (three days later), he’d implemented the whole feature. It worked fine for me the first time.

The most surprising changes were:

  • In XNA, the Rectangle constructor takes (int left, int top, int width, int height). In SharpDX, it takes (int left, int top, int right, int bottom). This led to all KINDS of amusing weirdness.
  • The Point type is gone, so I switched to Vector2 with some casting to int. Probably there is a better way but I don’t yet know it.
  • The XNA Color.Transparent is equivalent to Color(0, 0, 0, 0) — e.g. premultiplied black at zero alpha. In SharpDX, it is Color(0, 0, 0, 255) — e.g. black with full alpha. Everywhere I had been using Color.Transparent I switched to “new Color(0)” to get the same effect in SharpDX.
  • In XNA, the Color constructor takes (int r, int g, int b, int a). In SharpDX, it takes either (byte r, byte b, byte g, byte a) or (float r, float g, float b, float a). This caused some of my color math to use the float overload rather than the byte overload, with ensuing hilarity.
  • I ran into a premultiplied alpha problem with PNGs, which aren’t premultiplied. I posted an issue and Alex responded immediately AGAIN. I was able to hack around it with his suggested BlendState.NonPremultiplied workaround.
  • I tried using 32-bit premultiplied BMPs in RGBA format, but ran into ANOTHER issue, which, of course, I posted. We’ll see whether Alex maintains his exemplary responsiveness.

If you’re getting the idea that Alex is incredibly helpful, you’re right. He’s right up there with the excellent authors of the BASS audio library, about whom I’ve similarly gushed. The very best open source projects to use in YOUR open source project are the ones with active and helpful maintainers. And having an open source project of your own really helps get support, since you can show your code and they can point others at your code as an example of something cool done with their work.

So now Holofunk is fully running on SharpDX with all features maxed, multiple window and two-player support, and much faster rendering. It looks pretty much the same, but now all obstacles to video texturing, bizarre postprocessing, Fourier transforms on the GPU, etc., etc., are removed. The sky is now the limit.


Next up: sound effects! At last!

Now that I’ve gotten that big move over with, it’s time to start putting sound effects in at last! I bought a copy of Sugarbytes Turnado, the VST plugin Beardyman uses in his live rig, and it is indeed friggin’ amazing. Been having all kinds of fun exploring it.

The tricky part is that it does eat CPU, and I’m not sure how many instances of it I will be able to create with the BASS audio library I’m using. So while part of me wants an interface that lets me apply any random set of effects to each and every individual loop, that would mean one instance of Turnado per loop. In Holofunk it’s easy to create dozens of loops. So I needed some fallback story for how to manage sound effects in some more granular way.

I think what I will try first is splitting the screen into eight wedges (instead of the four quarters in the current version), with each wedge having its own instance of Turnado. So all loops in a given wedge will share a set of effects. It will be possible to select multiple wedges and wave your arms wildly to wiggle the Turnado knobs for all those wedges at once. It will also be possible to record animated knob-wiggling across a set of wedges. That, combined with effect selection, should be more than enough to get some serious madness going on, while being pretty straightforward to implement.

I also have an interesting idea for a graphical interface for scratching, but I’m going to show that one in prototype form rather than blog about it ūüôā

Meanwhile, Elsewhere In Loopania wins the big Looping Journalism Award of the last two months. They have an excellent and long article on Beardyman’s new live performance setup, which he said on Facebook will be coming soon to a TED talk near you. CAN NOT WAIT.

They also have a video of Imogen Heap with the latest iteration of her gestural music gloves. Here’s the video for your convenience — and look, she’s got a Kinect in there!

How ridiculously cool is THAT???

This entire field of musical experimentation is moving along most awesomely, and I’m greatly enjoying my own little part in it.

So: February is the month of Sound Effects Into Holofunk. March I plan another round of beta testing, aka getting together with my Holofunk posse and partying on it. April and May, more work, and then into demo season in June with a public performance at the Maker Faire. Going to try to be ready for a 30-minute gig this time!

Expect another update in March or so. Until then, stay funky!


Written by robjellinghaus

2013/02/07 at 00:27

Posted in Holofunk

A Publication! In Public!

with 7 comments

The team I work on doesn’t get much publicity.¬† (Yet.)

But recently some guys I work with submitted a paper to OOPSLA, and it was accepted, so it’s a rare chance for me to discuss it:

Uniqueness and Reference Immutability for Safe Parallelism

This is really groundbreaking work, in my opinion.¬† Introducing “readable”, “writable”, “immutable”, and “isolated” into C# makes it a quite different experience.

When doing language design work like this, it’s hard to know whether the ideas really hold up.¬† That’s one epic advantage of this particular team I’m on:¬† we use what we write, at scale.¬† From section 6 of the paper:

A source-level variant of this system, as an extension to C#, is in use by a large project at Microsoft, as their primary programming language. The group has written several million lines of code, including: core libraries (including collections with polymorphism over element permissions and data-parallel operations when safe), a webserver, a high level optimizing compiler, and an MPEG decoder. These and other applications written in the source language are performance-competitive with established implementations on standard benchmarks; we mention this not because our language design is focused on performance, but merely to point out that heavy use of reference immutability, including removing mutable static/global state, has not come at the cost of performance in the experience of the Microsoft team. In fact, the prototype compiler exploits reference immutability information for a number of otherwise-unavailable compiler optimizations….

Overall, the Microsoft team has been satisfied with the additional safety they gain from not only the general software engineering advantages of reference immutability… but particularly the safe parallelism. Anecdotally, they claim that the further they push reference immutability through their code base, the more bugs they find from spurious mutations. The main classes of bugs found are cases where a developer provided an object intended for read-only access, but a callee incorrectly mutated it; accidental mutations of structures that should be immutable; and data races where data should have been immutable or thread local (i.e. isolated, and one thread kept and used a stale reference).

It’s true, what they say there.

Here’s just a bit more:

The Microsoft team was surprisingly receptive to using explicit destructive reads, as opposed to richer flow-sensitive analyses (which also have non-trivial interaction with exceptions). They value the simplicity and predictability of destructive reads, and like that it makes the transfer of unique references explicit and easy to find. In general, the team preferred explicit source representation for type system interactions (e.g. consume, permission conversion).

The team has also naturally developed their own design patterns for working in this environment. One of the most popular is informally called the ‚Äúbuilder pattern‚ÄĚ (as in building a collection) to create frozen collections:

isolated List<Foo> list = new List<Foo>(); 
foreach (var cur in someOtherCollection) {
    isolated Foo f = new Foo();
    f.Name = cur.Name; // etc ... 
    list.Add(consume f); 
immutable List<Foo> immList = consume list;

This pattern can be further abstracted for elements with a deep clone method returning an isolated reference.

I firmly expect that eventually I will be able to share much more about what we’re doing.¬† But if you have a high-performance systems background, and if the general concept of no-compromises performance plus managed safety is appealing, our team *is* hiring.¬† Drop me a line!

Written by robjellinghaus

2012/11/02 at 14:06

Posted in Uncategorized

Holofunk fall update

with 3 comments

August was busy alright!

Despite all the business in my last post about SharpDX etc., I discovered that XNA 4.0 actually supports multiple windows quite straightforwardly, so being a lazy programmer I went with the easy route.¬† That version of the code is uploaded on CodePlex now.¬† I’m really happy with how it turned out!

Latency is Evil, Latency is Death

In my last post I also mentioned I met with some talented local loopers.¬† I didn’t mention that while demoing, a couple of them felt that Holofunk was just… too… laggy.¬† I was shocked by this as I’d been working for a long time to cut latency and I could only notice a subtle bit of it.¬† But they insisted it was no good.¬† So finally I thought to check the ASIO4ALL buffer size.¬† This was set to 512 samples, which at 48Khz (my current sampling rate) is just over 1/100 of a second.¬† That’s damn short!¬† But I shortened it yet further to 192 samples, which is 7/1000 of a second shorter.¬† And suddenly they loved it.¬† It felt seamless and right. ¬† And I realized they weren’t kidding — 7/1000 of a second really is very audible!

It turns out that this is well known.¬† Looping technology is a sonic mirror, and if it doesn’t line up perfectly, it really throws you off.

All of this made such a big impression on me that I made a real point of it at the Microsoft demo I gave in August, which you can now watch.

That went well.¬† I won a runner-up prize in the “So Fun” category.¬† My use of a Wiimote kind of disqualified me, since it was a Kinect-for-Windows-sponsored contest and all.¬† I consider that fair; the applause was reward enough!

Then I did another gig at my sister’s wedding in Boston.¬† Unfortunately I ran into a bizarre situation I’d never encountered before:¬† my microphone sounded fine, but the Holofunk loops weren’t playing at all.¬† This despite the fact that there was only one stereo pair going into the DJ’s mixer!¬† I could not understand how this could be happening, and it almost blew my whole show in front of 150 people (no pressure!), but finally the DJ yanked one of the wires off and suddenly it worked.¬† Some bizarre kind of phase problem?¬† I hadn’t caught it during sound check because I just checked the microphone.¬† Lesson learned: SOUND CHECK EVERYTHING!¬† Still, it wasn’t a total disaster and many people told me they enjoyed it, so all’s well that ends well.

Plus, I took it to Cape Cod for our post-wedding family vacation, and my sister (a trained Bulgarian folk singer) turned out to be awesome at it.¬† She was very impressed and wants to play with it more.¬† Sooner or later I’ll need to package it for easier distribution.

Sound Weirdness Mega-Party

Then, Tim Thompson of Kinect Space Frame fame came into town for the Decibel Festival.  He very graciously wrote me and asked if we could meet and maybe do some kind of event.  He then contacted a local makerspace, Jigsaw Renaissance, and they got enthusiastically on board.  We wound up hanging out for a few hours, making many weird sounds, and having many interesting brainstorms with plenty of attendees.  It was all kinds of festive!

One highlight was meeting Tarik Barri, who had some cool looping video of various animated headshot clips of himself.¬† It was exactly the kind of thing I have in mind for Holofunk at some point — clipping out live video of the performer’s head, and looping that in place of the little circles, basically making a live version of Beardyman’s Monkey Jazz piece.¬† Check out¬†Tarik’s animated face fun (slightly NSFW), and this 3D sound-space, which is also very inspirational for Holofunk’s head-mounted future at some point.

What was especially neat about this evening was that I felt, for the first time, that Holofunk can hold its own in a roomful of weird hacker electronic music projects.¬† It might not be ready for prime time, but it’s definitely ready for backstage with the big dogs!¬† Next year I’ll be working to get it into the Decibel Festival in some manner, for sure.

Hiatus, Interrupted

As far as actual coding goes, I’ve been in a low-hacking mode since the end of August, focusing instead on various other types of software, namely Diablo III, Borderlands 2, and XCOM ūüôā¬† Fall is the biggest gaming season of the year and I’ve been indulging.¬† It’s been great.¬† But the worm is turning and it’s time to get back to Holofunk.

After adding the dual-monitor stuff, which turned out so well, I’m pretty clear that the next great feature is two-player support.¬† This is technically possible with just the hardware I have now — I can already connect two mikes to my USB audio interface, two Wiimotes via Bluetooth, and Kinect can do two-person skeletal tracking.¬† All I have to do is to refactor the guts of the code to support two of everything.¬† Right now I think I am going to let both players “step on each other” — e.g. each person can move and touch anywhere on the screen.¬† This will introduce some weird boundary cases, but should make for more entertaining play, if you can muck with the sounds the other person made.

The biggie after that is to add VST plugin support, particularly for the Turnado plugin from SugarBytes.¬† The reason that one is so important (despite its not inconsiderable cost) is that my inspiration Beardyman uses it in his new iPad-based software performance setup.¬† Bang, that’s the only recommendation I care about in the whooooole world.¬† Have a listen at this and imagine it in Holofunk.¬† Hell yes.

Of course, this is going to kick the complexity of the whole thing to another level altogether.¬† The main conceptual problem I’ve had for a long time is simply what the interface should be.¬† On the one hand I want it to be very simple and approachable; on the other hand, I want to be able to do ridiculously layered compound effects.¬† And, as with all Holofunk features, there has to be a smooth ramp from the simple to the sophisticated.

Here’s what I’m thinking:

  • There’s an “effects mode” you can enter.
  • When in “effects mode”, your hands aren’t selection cursors anymore; they’re “knobs.”¬† Waving the knobs around with the Wiimote changes parameters.¬† (Up/down = one parameter; left/right = another; forward/back = another.)¬† This would give six axes of parameter control just with your two hands, which is enough for starters (though really your feet will have to get in on the fun at some point…).
  • There needs to be some menu interface for assigning parameters to axes.¬† In other words, you should be able to click somewhere and select left/right for pan and up/down for LFO frequency, or whatever.
  • Then you should be able to set all your knob parameters as presets on the Wiimote D-pad, so you push up/down/left/right and instantly get a set of six parameters mapped to your two hands.
  • THEN, holding down the A button activates your effects and lets you immediately mutate the sounds that you were just pointing at.
  • THEN, holding down the A button and the trigger records your parameters as a loop!

So imagine an interaction like this:

  1. Squeeze the trigger, laugh a little “Ho ho ho!”, let go.¬† Now you have a loop going “Ho ho ho!¬† Ho ho ho!¬† Ho ho ho!” forever.
  2. Push the D-pad to pick the “pan = left/right” preset.
  3. Hold¬†the A button over your “Ho ho ho!” loop, and wave your hand left and right.¬† Now Santa Claus is jumping from the left channel to the right channel and back.¬† When you stop waving your arm, Santa settles down.
  4. Now hold the A button and squeeze the trigger while you do a full circle with your arm, and then release it.  Santa Claus will now be looping from one speaker to the other.  Basically you recorded an animated envelope of the side-to-side panning.

The A button becomes the “apply effect” button, and the trigger retains its “record loop” behavior… you’re just combining them into a single gesture.¬† There still needs to be some way to affect the microphone itself (rather than just the selected loops) — I still need to figure that part out a bit better.¬† Maybe¬†hold A while¬†initially holding¬†the mike and remote close together….

Basically, animated parameters needn’t have the same duration as the loops they apply to, and it should be possible to apply multiple animated parameters to a single loop or set of loops.¬† This should rapidly compose into brain-meltingly bizarre configurations of sound.¬† It might also make sense to add some kind of visual feedback for various parameters (e.g. use half-circles for fully panned sounds, etc.).¬† As with all Holofunk UI ideas, I don’t really know if this will work, but I do think it’s implementable and conceptually reasonably solid.

I also want to add scratching/sampling effects but I have not yet figured out how I want the interface to work, so I’m leaving that on the subconscious back burner until¬†I get some kind of inspiration.¬† Just getting multiple animated, looped¬†effects working will be plenty of amazeballs on its own!

So, Stay Tuned

It’s pretty mind-blowing that it was only a bit over a year ago that I was in Vancouver demoing all this to Beardyman.¬† It’s been a fantastic project so far and I expect it to become rapidly more so, as I get more features in and as I start collecting local technopeeps to play with it.¬† One of the other local loopers I demoed it to in June was Voidnote (and why did I not check out his Soundcloud before now?).¬† He actually wanted me to add guitar control to Holofunk, so he could use his guitar neck as a cursor, and use pedals in place of Wiimote buttons!¬† This is of course an awesome idea — how cool would it be to have a guitar/microphone two-player Holofunk jam?!¬† That’s on the radar as well.

My ultimate goal is to do a Holofunk gig at the annual Friends & Family rave campout.¬† I spent my twenties raving with that wacky bunch of Bay Area freaks, and I want to return as senior alumnus bearing live techno insane performance gifties.¬† That’s nine months away, and some of the hairiest features ever between now and then.¬† But if I can get two-player support by end of November, and animated Turnado support by end of February or March, and a couple more effects and maybe some video by June… then I’ll be ready!!!

Thanks again to everyone who’s enjoyed this project so far.¬† I’ve learned that one of my deepest satisfactions in life is working on a single project for years.¬† I’m loving raising my kids for that reason; my job remains excellent after four and a half years with no end in sight; and Holofunk is just getting rolling after 14 months.¬† Let’s see what the next 14 months bring!

Written by robjellinghaus

2012/10/18 at 22:41

Posted in Holofunk

SlimDX vs. SharpDX

with 11 comments

Phew!¬† Been very busy around here.¬† The Holofunk Jam,¬†mentioned last post, went very well — met a few talented local loopers who gave me invaluable hands-on advice.¬† Demoed to the Kinect for Windows team and got some good feedback there.¬† My sister has requested a Holofunk performance at her wedding in Boston near the end of August, and before that, the Microsoft Garage team has twisted my arm to give another public demo on August 16th.¬† Plus I had my tenth wedding anniversary with my wife last weekend.¬† Life is full, full, FULL!¬† And I’m in no way whatsoever complaining.

Time To Put Up, Or Else To Shut Up

One piece of feedback I’ve gotten consistently is that darn near everyone is skeptical that this thing can really be useful for full-on performance.¬† “It’s a fun Kinect-y toy,” many say, “but it needs a lot of work before you can take it on stage.”¬† This is emerging as the central challenge of this project: can I get it to the point where I can credibly rock a room with it?¬† If I personally can’t use it to funk out in an undeniable and audience-connected manner, it’s for damn sure no one else will be able to either.

So it’s time to focus on performance features for the software, and improved beatboxing and looping skills for me!

The number one performance feature it needs is dual monitor support.¬† Right now, when you’re using Holofunk, you’re facing a screen on which your image is projected.¬† The Kinect is under the screen, facing you, and the screen shows what the¬†Kinect sees.

This is standard Kinect videogame setup — you are effectively looking at your mirrored video image, which moves as you do.¬† It’s great… if you’re the only one playing.

But if you have an audience, then the audience is looking at your back, and you’re all (you and the audience) looking at the projected screen.


No solo performer wants their back to the audience.

So what I need is dual screen support.¬† I should be able to have Holofunk on my laptop.¬† I face the audience; the laptop is between me and the audience, facing me; I’m watching the laptop screen and Holofunking on it.¬† The Kinect is sitting by the laptop, and the laptop is putting out a mirror-reversed image for the projection screen behind me, which the audience is watching.

Like this:

With that setup, I can make eye contact with the audience while still driving Holofunk, and the audience can still see what I’m doing with Holofunk.

So, that’s the number one feature… probably the only major feature I’ll be adding before next month’s demos.

The question is, how?

XNA No More

Right now Holofunk uses the XNA C# graphics library from Microsoft.  Problem is, this seems defunct; it is stuck on DirectX 9 (a several-year-old graphics API at this point), and there is no indication it will ever be made available for Windows 8 Metro.

I looked into porting Holofunk to C++.¬† It was terrifying.¬† I’ll be sticking with C#, thanks.¬† But not only is XNA a dead end, it doesn’t support multiple displays!¬† You get only one game window.

So I’ve got to switch sooner rather than later.¬† The two big contenders in the C# world are SlimDX and SharpDX.

In a nutshell:¬† SlimDX has been around for longer, and has significantly better documentation.¬† SharpDX is more up-to-date (it already has Windows 8 support, unlike SlimDX), and is “closer to the metal” (it’s more consistently generated directly from the DirectX C++ API definitions).

As always in the open source world, one of the first things to check — beyond “do the samples compile?” and “is there any API documentation?” — is how many commits have been made recently to the projects’ source trees.

In the SlimDX case, there was a flurry of activity back in March, and since then there has been very little activity at all.  In the SharpDX case, the developer is an animal and is frenetically committing almost every day.

SharpDX’s most recent release is from last month.¬† SlimDX’s is from January.

Two of the main SlimDX developers have moved on (as explicitly stated in their blogs), and the third seems AWOL.

Finally, I found this thread about possible directions for SlimDX 2, and it doesn’t seem that anyone is actively carrying the torch.

So, SharpDX wins from a support perspective.  The problem for me is, it looks like a lot of DirectX boilerplate compared to XNA.

I just, though, turned up a reference to this other project ANX — an XNA-compatible API wrapper around SharpDX.¬† That looks just about perfect for me.¬† So I will be investigating ANX on top of SharpDX first; if that falls through, I’ll go just with SharpDX alone.

This is daunting simply because it’s always a bit of a drag to switch to a new framework — they all have learning curves, and XNA’s was easy, but SharpDX’s won’t be.¬† So I have to psych myself up for it a bit.¬† The good news, though, is once I have a more modern API under the hood, I can start doing crazy things like realtime video recording and video texture playback… that’s a 2013 feature at the earliest, by the way ūüôā

Written by robjellinghaus

2012/07/18 at 23:54

Posted in Holofunk, Uncategorized


with one comment

Life has been busy in Holofunk land!  First, a new video:

While my singing needs work at one point, the overall concept is finally actually there:  you can layer things in a reasonably tight way, and you can tweak your sounds in groups.

Holofunk Jam, June 23rd

I have no shortage of feature ideas, and I’m going to be hacking on this thing for the foreseeable future, but in the near term:¬† on June 23rd I’m organizing a “Holofunk Jam” at the Seattle home of some very generous friends.¬† I’m going to set up Holofunk, demo it, ask anyone & everyone to try it, and hopefully see various gadgets, loopers, etc. that people bring over.¬† It would be amazing if it turned into a free-form electronica jam session of some kind!¬† If this sounds interesting to you, drop me a line.

Demoing Holofunk

There have been two public Holofunk demos since my last post, both of them enjoyable and educational.

Microsoft had a Hardware Summit, including the “science fair” I mentioned in my last post.¬† I wound up winning the “Golden Volcano” award in the Kinect category.¬† GO ME!¬† This in practice meant a small wooden laser-etched cube:

This was rather like coming in third out of about eight Kinect projects, which is actually not bad as the competition was quite impressive — e.g. an India team doing Kinect sign language recognition.¬† The big lesson from this event:¬† if someone is really interested in your project, don’t just give them your info, get their info too.¬† I would love to follow up with some of the people who came, but they seem unfindable!

Then, last weekend, the Maker Faire did indeed happen — and shame on me for not updating this blog in realtime with it.¬† I was picked as a presenter, and things went quite well, no mishaps to speak of.¬† In fact, I opened with a little riff, aand when it ended I got spontaneous applause!¬† Unexpected and appreciated.¬† (They also applauded at the end.)

I videoed it, but did not record the PA system, which was a terrible failure on my part; all the camera picked up was the roar of the people hobnobbing around the booths in the presentation room.  Still, it was a lot of fun and people seemed to like it.

My kids had a great time at the faire, too.  Here they are watching (and hearing) a record player, for the very first time in their lives:

True children of the 21st century ūüôā

Coming Soon

I’ll be making another source drop to soon — trying to keep things up to date.¬† And the next features on the list:

  • effect selection / menuing
  • panning
  • volume
  • reverb
  • delay
  • effect recording
  • VST support

Well, maybe not that last one quite yet, but we’ll see.¬† And of course practice, practice, practice!

Written by robjellinghaus

2012/06/09 at 00:20

Posted in Holofunk, Uncategorized

Science fair time!

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Holofunk has been externally hibernating since last September; first I took a few months off just on general principles, and since then I’ve been hacking on the down-low.¬† In that time I’ve fixed Holofunk’s time sync issue (thanks again to the stupendous free support from the BASS Audio library guys).¬† I’ve added a number of visual cues to help people follow what’s happening, including beat meters to show how many beats long each track is, and better track length setting — now tracks can only be 1, 2, or a multiple of 4 beats long, making it easy to line things up.¬† Generally I’m in a very satisfying hacking groove now.

And today Holofunk re-emerges into the public eye — I’m demoing at a Microsoft internal event dubbed the Science Fair, coinciding with Microsoft’s annual Hardware Summit.¬† Root for me to win a prize if you have any good karma to spare today ūüôā¬† I’ll post again in a day or two with an update on how it went.

I’ve also applied to be a speaker at the Seattle Mini Maker Faire the first weekend in June — will find out about that within a week.¬† If that happens, then I’ll spread the word as to exactly when I’ll be presenting!

Written by robjellinghaus

2012/05/10 at 06:33

Posted in Holofunk, Uncategorized

Holofunk: one month later

with 3 comments

It’s been a very interesting month despite the fact that I haven’t touched a line of Holofunk code!¬† I want to deeply thank everyone who’s expressed excitement about this project — it has been a real thrill.

First I have a favor: if you like Holofunk, please like¬†Holofunk’s Facebook page — that is a great way to stay in touch with this project and with other links and interesting things I discover.

In this post I want to mention a variety of other synesthetic projects that people have brought to my attention, and I want to recap the places that have been kind enough to mention Holofunk.

First and foremost, let me say that, as with my first Holofunk post, I find all of these projects very thought-provoking and impressive, and I am linking them here out of appreciation and excitement.  Since I have many plans for Holofunk, I do find myself wanting to take various aspects of these projects and build them into Holofunk.  I sincerely hope that the artists and engineers who have produced this work are appreciative of this, rather than threatened or irritated by it.  There are obviously a lot of us creating new musical/visual art out there, and I hope that others are as inspired by my work as I am by theirs.

Holofunk is and will remain open source, under the very permissive Microsoft Public License, so if anyone who’s inspired me winds up wanting to make use of something I’ve done, it¬†is entirely possible.¬† (Please let me know if you do, though, as I’ll be very interested and pleased!)

Synesthesia On Parade

One project Beardyman mentioned to me was Imogen Heap’s musical data gloves.¬† It took me a while to get around to looking them up, but when I eventually did I was gobsmacked:

Imogen Heap is of course a brilliant and well-known artist, and these gloves are her vision for where she wants to take her performance.  Her technical partner in this project is Tom Mitchell, a Bristol professor of music who was kind enough to reply when I wrote him a gushing email.

The system he’s developed with Imogen is best documented by this paper in the proceedings of the New Interfaces for Musical Expression 2011 conference.¬† And now I need to go off and download and read the complete proceedings, because it’s all right up Holofunk’s alley.

Tom and Imogen are using 5DT data gloves, which are $1,500 for a pair with a wireless connection, as well as a pair of¬†AHRS position sensors (about $500 each).¬† So their hardware is out of my hobby-only price league.¬† I am interested in the Peregrine glove (only $150 per), but unfortunately it’s exclusively left-handed at present, though I wrote them and they said Holofunk was quite exciting and they would love to be involved, so there’s hope!¬† Anyway for now I will stick with Wiimotes as they are cheap and relatively ubiquitous.

Latency is a huge concern for Tom — the AHRS position sensors have a 512Hz update cycle, which is extremely impressive.¬† The Kinect will never come close to that, which again motivates sticking with some additional lower-latency controls.¬† Plenty of people I showed Holofunk to at Microsoft want me to build a Wiimote-less version, and I probably will experiment with that — including using the Kinect beam array as the microphone — but it honestly can’t compete with a direct mike and button/glove input as far as latency goes.¬† Darren (Beardyman) specifically mentioned how impressed he was that I’d gotten the latency right (or at least close to right) on Holofunk; evidently lots of programmers he talks to build things that are very latency-unaware, making them useless for performance.¬† So while a pure-Kinect version would be very interesting (and obviously quite marketable!), it’s not my priority.

I am hoping to make some waves inside Microsoft as far as getting better low-latency audio support in Windows… ASIO shouldn’t be necessary at all, Windows — and Windows Phone — should be able to do low-latency audio just as well as the iPhone can!¬† And for proof that the iPhone gets this right, here’s our friend Darren rocking the handheld looper:

The app there is evidently Everyday Looper, and dammit if it shouldn’t be possible to write that for Windows Phone 7, but I don’t think it can be done yet.¬† This will change, by Heaven.¬† In fact, writing this post got me to actually look the app up, and that turns up this stunningly cool video demonstrating how it works.¬† Plenty of inspiration here too:

Good God, that’s cool.

One other project Tom mentioned is the iPhone / iPad app, SingingFingers:

That’s synesthesia in its purest form:¬† sound becomes paint, and touching the paint lets the sound back out.¬† I totally want to build some similar interface for Holofunk.¬† Right now¬†a Holofunk¬†loop-circle is dropped wherever you let go of the Wiimote trigger while you’re recording it, but it would be immensely straightforward to instead draw a stroke along the path of your Wiimote-waving, and then animate that stroke with frequency-based colors.¬† It would also be fascinating to allow those strokes to be scratched back and forth, though I’m not yet sure that a freeform stroke is the most usable structure for scratching.

The fellows behind SingingFingers have various other projects, equally crazy and intriguing.

I am sure I will turn up a colossal quantity of other excellent projects as I move forward with Holofunk, and I will certainly blog the pants off of them because it’s dizzying how much work is being done here, now that every computer and phone you touch can crank dozens of realtime tracks through it.¬† Wonderful time to be an electronic musician, and the future is dazzling…

Holofunk Gets Press

I also very much appreciate the sites that have linked to Holofunk.

Bill Harris, an excellent sports/gaming blogger, was nice enough to mention Holofunk.

Microsoft’s Channel 9 site put together a¬†good description of Holofunk.

The number one Kinect hacking site on the web,, asked me to write up a description of Holofunk, which they posted.  They get mad hits, so this is lovely.  An experimental music/art collective in Boston, CEMMI, already contacted me as a result of the kinecthacks post!

…And now that I am surfing, I find that I might be wrong about how possible it is to do Holofunk with just Kinect.¬† This guy seems to get a lot of pretty fast wiggle action going on here:

Getting effects like that into Holofunk is definitely on the agenda for early next year.

Still Taking It A Bit Easy

Now, all that wonderfulness having been well documented , I must confess that I am still on low¬†hacking capacity, Holofunk-wise.¬†¬†And here’s where this post veers into totally off-topic territory, so you’ve been warned!

I’m a gamer, you see, and Q4 of every year is the gamer’s weak spot.¬† I’ve been playing the heck out of Deus Ex: Human Revolution, a really excellent homage to a¬†famous game from ten years ago.¬† I¬†played that game then, and I’m¬†totally¬†digging this one now.

Then on November 11th, the unbelievably huge game Skyrim ships.¬† My friend Ray Lederer is one of the lead concept artists on the game (check out this video of him at work), and the game could take over a hundred hours to complete, so that’s a month and a half shot right there.

And THEN, soon after THAT, the expected-to-be-superb Batman: Arkham City game comes out.  I played the first Batman game from these guys to smithereens, and I am expecting to do likewise with this one.

So… yeah… the next few months have some stiff competition.¬† However, given how much excitement there is around Holofunk, I do plan to make these be the only games I play in 2011.¬† There are just not enough hours in the day to read, watch, listen to, or play every good book, movie, track, or game in the world, LET ALONE do any actual work of one’s own!¬† So one has to be picky, and the above are my picks.

But Once That’s Over¬†With…

My only specific goal for Holofunk in 2011 is to rewrite the core audio pump in C++ to get away from the evil .NET GC pauses.

Then, in 2012, I plan to get seriously down to business again, feature-wise.

The number one feature is probably going to be areas — chopping up the sound space into six or so regions, and allowing entire areas to be muted or effected as a whole.¬† That will allow Holofunk to become useful for actual song creation, since you’ll be able to bridge into other portions of a song in a coherent way.

The second feature will probably be effects.¬† Panning, volume, filtering, etc. — adding that stuff will do a huge amount for making Holofunk more musically interesting.

Then will come visuals — SingingFingers meets Holofunk.¬† Should make the display radically more interesting and informative.

After that, probably scratching / loop-cutting.¬† I have no idea what the interface will be, but being able to chop up loops and resample them is part of every worthwhile looper out there (see Everyday Looper’s awesome video above), so Holofunk has got to have it.¬† Going to be challenging to do it with just a Wiimote, but it’s got to be possible, it’s GOT to be!

And then, most likely, video.¬† Stenciling out Kinect video and time-synchronizing it with the loops could be all kinds of wacky fun — I cited this in my last blog post as the “live Monkey Jazz” possibility.

All that together should hopefully take only until mid-2012 or so, at which point I want to start rehearsing with it in earnest and actually performing with it.¬† If I can’t get a slot at a TEDx conference, I’m just not trying hard enough.

Thanks as always for your interest, and stay in touch — 2012 will be an epic year!¬† I feel much more confident saying things like that now that I’ve actually gotten this project off the ground ūüôā

Written by robjellinghaus

2011/10/09 at 22:05

Posted in Holofunk, open source