How-to export loops for games with Live and DP

Mike and I are creating the Snowferno soundtrack in Ableton Live and Digital Performer. Each track is meant to loop of course, so (at least within the limitations of the phone hardware) we want the loop's seams to be as transparent as possible.

Both Live and DP have great features for looping playback, but exporting the final audio from each app as a loop requires two different approaches.

Live is totally loop-centric out of the box, so there is simply a switch in the "Export Audio/Video..." window to "Render as Loop". This switch causes Live to do something pretty cool. It makes *two* passes of the track and uses the first pass to calculate what reverb tails, delay feedback, and so on should carryover and be sounding at the beginning of the exported audio file.

DP is more linear by design, so it doesn't provide a one-click solution. You need to fake it -- which I do by pasting a copy of the final measure of MIDI again before the first measure of the loop. My "Bounce to Disk" selection area includes that pre-measure as well as one extra measure of breathing space beyond the last measure of the loop. I set the "Bounce to Disk" window Import setting to "Add to Sequence" and then bounce it. Next, I slice out the exact region of the loop from the just-bounced/imported soundbite minus the extra pre/post measures and export that soundbite from the Soundbites List. It helps if you rename the sliced soundbite and delete the unused bits. It's little more work, but it gets all the material that will still be sounding at the end so that it can be triggered and sounding still at the beginning of the track. Plus, I've found DP needs a little space for things to ramp-up and down. Adding those pre/post measures lets all my Waves processors get humming far away from the parts of the audio where a loop seam will be.

The final loops go in to Unity as AAC-encoded files so that the iPhone decodes it in hardware. We're still experimenting with what the final bitrate will be -- once all the tracks are done, we're going to find the balance between great-sounding music and needless app size bloat.

Welcome to the development blog!

Today i am going to try out the new development blog! The snowferno website is nearly ready to go live, so this is where all the new content will live.. for older stuff (although there isnt much) you can check out my blog at : benbritten.com/blog or the Rollover blog at fatlabmusic.com/blog.

So, to kick things off let me just give a bit of backstory on this project. We started it roughly at the end of the year last year (sort of xmas time 2008). And by 'started' I mean we decided that we wanted to collaborate on an iPhone game, tho we had no idea what to make.

Ultimately the idea to do a rolling ball game was made, I think mostly because the 'rolling ball game controlled with the accelerometer' seems to be the 'hello world' of game genres on the iPhone. So it seemed like the right place to start.

In early january I started looking at my options for coding the game ( I am doing all the coding, the boys at Fatlab are doing all the sound/music and most of the level design). I knew we were going to want to use 'real' physics, so that was really the only requirement I started out with.

I have written my own 'game engines' (if they can be called that, a more apt term might be 'openGL|ES code harness') and was trying to figure out how long it would take me to bolt a physics engine onto my existing tool base.

During this time I looked at a dozen or so open source physics libraries, and they all looked capable enough. However I also remembered my old friend Unity, and had heard that they recently released something that could build apps for the iPhone.

So, in the midst of downloading and evaluating all the physics libraries I also got a trial copy of unity and tried to build a quick prototype. Turns out, Unity has a pretty shallow learning curve, and I had a working prototype 'level' (if you could call it that) in about 3 hours.

That pretty much sealed the deal for me and Unity. I bought a copy later that week and started learning Unity in earnest.

This is about the same time that the Fatlab boys came up with the excellent idea of the snowball rolling through hell. Thus, Snowferno was born :-)