The goal here is to have Ableton Live transmit all track data and user actions to a C++ program which can use that data to generate unique visuals. If you want to create interactive visuals for a music performer, the obvious way is to use a live audio feed. However you can only do so much with such a feed and visuals end up only responding to the master level. With the help of a tool called LiveOSC, it’s possible to get OSC data out of Ableton Live. OSC or Open Sound Control is a data format which is usually transmitted over a wifi using a protocol called UDP, and this data can be picked up by a C++ application. In this case we’re using a C++ framework called Cinder and the OSC is interpreted into visualizations. This OSC data can tell us stuff like:
– when the set begins or ends
– when each beat occurs (as in once a second for 60 bpm)
– when any track level or the master level is changed
– when the user switches to the next track
– when the user tweaks any knob
I’m using the following tools to accomplish this task.
Ableton Live gets LiveOSC
There’s not much help on the site, but it really is that simple to get it working.
1. install python 2.5.1 (Do not skip!)
2. place LiveOSC in Live.App/Contents/App-Resources/MIDI Remote Scripts/
3. go to Preferences -> MIDI Sync and select LiveOSC as a Control Surface
Live should now be transmitting OSC data over UDP on port 9001, as well as listening on port 9000. However we don’t yet have a way of listening to the transmission. You could probably use some sort of network monitoring tool to check if it’s working. But it’s actually easier to proceed with setting up the next tool, Cinder, since it comes with a sample app called OSCListener which will pick up this OSC data and parse and display it.
[As an aside, by default LiveOSC seems to transmit to it’s own host machine’s IP, my next goal is to make it transmit to a different IP]
Listening with Cinder
Once you are setup correctly, you should be able to launch any of the sample apps that the Cinder library comes with. Go into cinder/blocks/osc/samples/OscListener/ and then launch either the Xcode or VS2010 app depending on your platform of choice.
Now in the source file OscListenerApp.cpp, make one simple change. Look for the following line and change the port number from 3000 to 9001:
Now run OscListenerApp and then go to Ableton Live and move the master level slider up and down. You should see some OSC data pop up in you Xcode console!
The master level slider will also effect the OscListener app screen. The white part of the window should extend to the right as you increase the volume. This slider will have this effect while others may not. In the code the simple visual effect is only performed when the first argument is a float.
Making sense of the OSC
Things to note:
– we get a message on start and stop with the address /live/play
– we get a message on every beat with the address /live/beat
– we get a message when switching tracks with the address /live/clip/info
– the last argument in some cases is an int that represents the following values:
0 = empty
1 = stopped
2 = playing
3 = triggered
So the 3 /live/clip/info messages were sent when I triggered the new clip, the old clip stopped, and the new clip started.
TouchOSC talks to Cinder
This section is not really related to the above, but is another simple proof of concept. Another way to send OSC signals to a Cinder app is to use your phone. Just install an app called TouchOSC (free on Android, $5 and more full featured on iOS). Make sure your phone and computer are connected to the same wifi network, open up TouchOSC, and configure it with the following settings:
Host: 192.168.1.2 Port (outgoing): 9001
Port (incoming): 9000
Now just start up one of the touch layouts in TouchOSC, start up your OscListener app, and like magic, you should see messages coming in to your Cinder app.