iPhone DJ software mockup

[Michael]

I had a look at DJ software for the iPhone/iPod touch recently. Nothing substantial has shown up yet. So I mocked this up:



Key points:

- Overall the functionality would mimic Pioneer CDJs + DJM mixers.

- Eject button would allow the user to select a new track from their music collection, bringing up a new screen to do so.

- Knobs would be activated by the user pressing down on them and holding as they slide their finger up/down or left/right, and deactivated when the user released their finger from the screen.

- Active knobs/faders/pads would light up/glow to indicate they are selected. No other knobs on that channel would be affected if the uses finger slid over them.

- Double-tap would return knobs to their default position.

- Faders would be controlled with up/down finger movements in the same manner as knobs. Thanks to the multitouch capability of the iPhone you could adjust EQs + faders on both channels simultaneously.

- The time info display above the play/cue buttons would also serve as a nudge pad, where the user could tap + slide up/down to nudge the track. This should probably be made clearer in the UI.

- Sound output through the headphone jack would be split: Master on the left, headphones on the right. This means all output would be mono, which sucks, but it's better than nothing. The user would buy a stereo -> 2 x mono cable splitter like this:



- It might also be possible to output the headphone output via the stereo jack and master output over wifi, but if this incurred a delay it might make DJing difficult.

The only thing I can think that's missing is effects, booth monitor control and beat syncing. I'd argue that effects aren't high priority enough to take up screen real estate, beat syncing is for pussies, and the booth monitor could just be the master output signal split again. This means your booth speakers would need a hardware volume knob though.

Obviously this wouldn't be a replacement for decks, but it would be great fun for house parties - certainly more useful than a lot of the current "DJ" apps on the iPhone. My biggest concern is that the screen is simply too small to fit the number of controls on at once. What do people think?

[LeonSmith]

beat syncing is for pussies

True dat.

[Milligna]

To get around the Size issue, you could divide the console up into zoomable sections - you could have the full view of the console visible, but to change the finer settings you could tap once on the section you're interested in and it will zoom in to a view where you have finer control over what your slider is set to then tap on an icon in the corner to zoom out again.

[Shaneus]

Or switch between channels... I haven't used an iPhone yet, but from what it looks like, the pots may be too small to adjust via the touch screen. A better option may be something that's fully featured that offers the option of toggling between channels as well as having both channels on the screen at the same time. That would also give you the option of having more things that can be adjusted if you so wish.

[Michael]

Kev - yeah I considered that, but one of the key things I wanted to avoid was having to scroll or press modifiers to get at the core functionality. DJing requires a very immediate "hands-on" approach, so I wanted to ensure all the basic functionality for mixer and both decks was accessible at once.

I could probably free up some room by adding a button that went to a second screen, which contained the master volume, headphone volume and ability to change tracks for each deck, but everything else on there should be readily available at all times.



Shaneus, yeah giving the user options like that would be good, but I reckon there's enough room - if you load the pic above onto an iPhone you'll see there's ample room to touch, and once you've made contact there isn't a space issue since your movements will only affect that knob until you release your finger.

[Michael]

If anyone is interested, I discovered a physical limitation of the iPhone which prevents more than one audio file being played back using hardware compression at once, which basically rules out two MP3s playing simultaneously. So you'd either have to do it with WAVs or software MP3 decompression, which doesn't sound like much fun.

Also I discovered you can't access the iTunes music library from within an app.

Boooooo!

[Ches]

Library access is coming in 3.0.

[Shaneus]

BTW Michael, I was looking at a friends iPhone and saw some DJ software on there, and he seemed pretty pleased with the way it behaved, but only as a single music source to cue up and play/pitch bend music. Pretty impressed with some of the stuff on there... especially the basic but (seemingly) decent sequencer that was on there.

Bet you can do better though

[Miles]

Library access is coming in 3.0.

I love that Michael's an iPhone dev but knows less than us

[Michael]

I'm not REALLY an iPhone dev. I'm a gold rushing hack aiming for a quick buck, and have learned the absolute bare minimum possible for 2.2.1 to get my app out there. You know this. I've had nothing to do with 3.0 yet because I simply can't switch over to it as I need 2.2.1 for development/testing.

[Gamma]

If anyone is interested, I discovered a physical limitation of the iPhone which prevents more than one audio file being played back using hardware compression at once, which basically rules out two MP3s playing simultaneously.

I am interested, and that blows. I'm looking to make some "audio toy" apps with a mate of mine, thankfully the division of labour being him coding and me doing all the fun stuff. I'll let him know about this, cheers.

[Michael]

Yeah... as far as I know nobody has tried doing decoding one MP3 in hardware and decoding another one in software, but I imagine it would bring the iPhone to its knees as it's not a super-fast device... but you never know till you try. Still, you'd probably need to license the MP3 codec...

[Miles]

I'm not REALLY an iPhone dev. I'm a gold rushing hack aiming for a quick buck, and have learned the absolute bare minimum possible for 2.2.1 to get my app out there. You know this. I've had nothing to do with 3.0 yet because I simply can't switch over to it as I need 2.2.1 for development/testing.

Is this you with everything? It's like how you're a games programmer... but hate games

[Miles]

btw, iPhone is pretty awesome processor wise, it should be able to decode MP3 and uncompressed audio at the same time pretty easily...

[Michael]

Maybe in an isolated environment, but try it with 20 other background system processes which you have no control over...

[Miles]

Okay, I will.

[Michael]

Good.

[Miles]

This just in - it works fine.

In my head.

[Michael]

Science in action!

Actually, there is a Deadmau5 DJ/mixing app for the iPhone so maybe they've managed it, but I'm not paying the $3 to find out.

[Shaneus]

Perhaps it's more of a music sequencer than an on-the-fly solution. I just don't see how it could be done when you only have one output. Yeah, technically the twin mono channel output, but that's not really a viable option when you want half-decent sound quality/usability.