Re: [Jack-Devel] questions about latency ranges

Hi! I have some questions about the minimum and maximum values of a port's latency (i.e., its latency range). The documentation states the following: "Both latencies might potentially have more than one value because there may be multiple pathways to/from a given port and a terminal port." Does this also apply to a setup with two output ports "A" and "B" (representing two distinct physical devices) with different capture latency, which are both connected to the same input port "C"? Here are some details of an example setup (useful for demonstration purposes, but probably not for doing any real recording work) as reported by jack_lsp: "A" (Focusrite Saffire PRO 14 Firewire audio interface): firewire_pcm:00130e0402403491_1394/Out:01 (Mic/Lin/Inst:01)_in port latency = 337 frames port playback latency = [ 0 1792 ] frames port capture latency = [ 337 337 ] frames properties: output,physical,terminal, "B" (Line6 PODxt Live guitar effects processor synchronized by zita-ajbridge): line6_in:capture_1 port latency = 867 frames port playback latency = [ 1792 1792 ] frames port capture latency = [ 867 867 ] frames properties: output,physical,terminal, "C" (Ardour track): ardour:track 1/audio_in 1 port latency = 0 frames port playback latency = [ 1792 1792 ] frames port capture latency = [ 867 867 ] frames properties: input, Under the assumption that the physical inputs of "A" and "B" represent the same time scale, the correct answer for the port capture latency at port "C" would be [ 337 867 ] and not [ 867 867 ]. So my questions are: *) What is the rationale behind jack reporting the larger of the two latencies of "A" and "B" both as the minimum and maximum latency of "C", and ignoring the smaller one?

*) Is it possible to provide additional information to jack to state that the signals at "A" and "B" originate from the same physical source (or from different physical sources sharing the same time scale), such that both latencies of "A" and "B" are taken into account for the latency range of "C"?