Drivers are in-process, not out-of-process like most clients.

You could write two in-process clients. You could also write slave drivers, which are like backends but different in subtle ways.

On Sun, May 15, 2016 at 2:17 AM, Kjetil Matheussen <k.s.matheussen@gmail.com> wrote:

On Sat, May 14, 2016 at 1:41 AM, Paul Davis <paul@linuxaudiosystems.com> wrote:
You can't do duplex properly as a client. The main difference between a JACK "driver" (aka "backend") and a client is that a driver consists of two halves. One is executed at the start of a process cycle, to collect data from the hardware; the other is executed at the end of a process cycle, to deliver data to the hardware.

But why not just use two clients in the same program to achieve the same thing?