[LAD] JACK latency API clarifications

Stefano D'Angelo zanga.mail at gmail.com
Fri Feb 21 14:38:01 UTC 2014

Sorry guys, other two (silly?) questions:

1. apart from the process callback, which callbacks need to be
RT-safe? Looking around I found a master thesis [1] that says: "Apart
the JackProcessCallback callback, which is called in the realtime
audio thread for obvious reasons, all other callbacks are called
asynchronously in a specialized non-realtime thread, to avoid
notifications to interfere with audio processing", is that true?

2. may the system sample rate actually change (while a client is running)?

[1] http://retis.sssup.it/sites/default/files/realtime_low_latency_audio_on_linux.pdf

2014-02-21 1:08 GMT+02:00 Stefano D'Angelo <zanga.mail at gmail.com>:
> 2014-02-21 1:08 GMT+02:00 Paul Davis <paul at linuxaudiosystems.com>:
>> On Thu, Feb 20, 2014 at 6:05 PM, Stefano D'Angelo <zanga.mail at gmail.com>
>> wrote:
>>> > reset your port latencies.
>>> Ok, thanks (to Robin too). Can jack_recompute_total_latenices() be
>>> called from within the process callback too?
>> you cannot contact the server from with the process callback, so no.
>> and yes, it is NOT documented which JACK API calls do this.
> Ok, thanks a lot.
> Stefano

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