I am running Ardour 6.8 on pipewire 0.3.32 (jack). There appears to be an issue with the input meters at the bottom of the recorder tab: while the input meters are active for any connected tracks, the meters for the hardware inputs do not register any signal. I experience this behaviour on both my machines.
Using either native jack or alsa backends, the meters work as expected. Is this an Ardour bug or rather something to be fixed in pipewire? Is there any solution/workaround?
I have now heard back from Wim Taymans. The difference in behaviour appears to be due to the security model in pipewire (see below). Any chances ardour could be made compliant?
Ardour does jack_port_get_buffer() on a port that it did not create (the device capture ports). This is not allowed in PipeWire. If ardours wants to get data from the capture ports, it should connect to them.
-8<—
Ardour does connect them to a hidden port named “physical_input_monitor_enable”, but still only taps off the signal from a remote port. It is possible with JACK if those are physical and terminal ports (jack port meta-data), since those ports correspond to hardware and are unconditionally filled right at the start of every process cycle, before any client is executed.
Anyway as I said above, if it works with JACK, it’s a bug (or missing feature) in pipewire’s JACK emulation.