ofxXwax is an addon for openFrameworks
It uses the xwax library to decode a variety of digital vinyl control systems (Serato, Traktor, and Torq). The ofxXwax repository also contains some tools surrounding ScratchML.
ScratchOSC, An example/app is provided that uses ofxXwax and openFrameworks to send OSC messages describing the position of the record. To customize the data coming from ScratchOSC, modify the file data/settings.xml. You can download a binary for OSX here. The binary has been compiled with a special modification that allows you to use broadcast IP addresses.
If you wire up an Arduino to your crossfader and output a single byte at 115200 baud describing the crossfader position, ScratchOSC will also send the fader clicks.
These two examples should be combined into a single app, they were written before ofxXwax. AudioToScratchML will convert a recording of a scratching performance to ScratchML positional data. ImportALS will take an Ableton Live set exported from Serato Scratch Live and convert the fader clicks into ScratchML position/time data.
AudioToScratchML requires libsndfile to be installed. To get libsndfile running, follow the instructions here.
This app will stream a ScratchML file over OSC. Click the app to re-trigger the playback. ScratchMLToOSC also contains an example.xml ScratchML file.