Latency Compensation for busses

Just wanted people to know that many users have now sponsored development of the new feature “latency compensations for busses”.

The total sun at the moment is $240. If this feature matters to you please sponsor developing it.

x42 has said that a prototype of the feature already exists but it needs more work. I think a bigger sum might put the request closer to the top of the list of new features to implement.

Sponsor the feature here (create a new account if you have not yet visited the Ardour bug tracker (mantis):

What is the goal of that option?

Currently if you put a plugin with internal latency on a bus, then the signal from the outputs of the bus will be out of alignment (delayed) with respect to the signal coming from the outputs of tracks and other busses. Latency compensation in busses would correct this.

ok I see, is there a way to know if a plugin have internal latency?

As I understand it, plugins tell the host program their internal latency as part of the plugin protocol, and that’s how Ardour compensates for latency on tracks. The problem with buses is that compensating for latency is more complicated, for reasons that I don’t understand because I haven’t bothered trying to figure it out.
As for whether you can get a human-readable report on latency - I don’t know…

The increased complication is that latency compensation on tracks is done by merely delaying the playback of existing disk material by a (carefully) computed amount.

But for busses there is no pre-existing material from disk, so it requires a delay line approach, and the delay line must be click-free no matter how and when the delay time is changed.