Comment by zemo

in real-time? Well, I have thoughts, but I'm not super familiar with Ardour itself, so I'm not sure if you're trying to merge during a live performance or if you're talking more of a distributed studio recording session type situation. I have working knowledge of Reason and Logic and ChucK (which I use with JACK and do some networked OSC stuff with, although I haven't touched it in a few years).

The approach we use at Jackbox for making the state of an xbox game mutable to thousands of live viewers on twitch is to have lots of little CRDT values, mostly just counters and sets of strings, and you merge the little values independently of one another, which is very different from the situation of editing a text document, which is typically structured as one big value. I wonder if, for a DAW, you could merge at the track or control level instead of the workspace level. E.g., communicate as an independent value the state of an individual fader, and communicate either states or operations on that fader and have each client merge them. In this example, the fader's state would be encoded as a PN-counter with a range condition, and you'd replicate increment and decrement options, like it was a networked rotary encoder. So every mutable thing in the DAW would be a value having operations that can be merged, instead of having a single big value representing the entire state of the DAW. My use-case is also funky because I have potentially thousands of writers writing to the same key, but only a single reader, and the reader doesn't need an update at every change, so I use state-based CRDTs, but I think most other people using CRDTs use operation-based CRDTs. Also not sure how you would mutate two separate values transactionally or if that's a thing you even need.