[LAU] short audio drop out when new jack clients are created and connected

[Paul Davis]

On Tue, Nov 9, 2021 at 8:52 AM Peter P. <peterparker at fastmail.com> wrote:
>
> Hi,
>
> I am currently giving linux-show-player a try but the following problem
> might happen with other software as well.
>
> In linux-show-player audio files can be played back from a cue list.
> Each cue is implemented as a separate jack client. I am having the
> problem that starting a cue, while another one is already playing, is
> causing an audible drop out in the audio processing. When running the
> software under alsa, this does not seem to happen. I suspect that
> creating and connecting new jack clients causes this to happen. No xruns
> happen though. I can not reproduce this exactly, although it happens at
> about 30% of cue starts. Increasing jackd's buffer size does not help so
> far. How can I go about to debug this further?

A number of JACK-compatible applications disconnect/reconnect to JACK
based on certain things that they do. Clementine, for example, will
disconnect from JACK on stop, and reconnect on start. This is silly
behavior, but it is understandable why they ended up this way.

The first question is: which version of JACK are you using? If it is
JACK1, this behavior would be expected - connections in JACK1 are not
click-free. If it is JACK2, then it is more of a problem, since if you
are not using sync mode (typical), this should not happen.