Re: [proaudio] Real-time for audio

[Grant <emailgrant@xxxxxxxxx>]

>> I'm trying to set up a real-time system for audio playback via mpd.
>> I've booted to rt-sources with CONFIG_PREEMPT_RT enabled.  Do I need
>> to set up jack and follow the real-time instructions here:
>>
>> http://jackaudio.org/faq
>>
>> Is there anything else I need to do?
>>
>> - Grant
>
> Hi there
>
> I'm not familiar with mpd at all but a realtime kernel for this seems a bit
> overkill. The way I see it is a realtime kernel is tuned for low latency
> interactivity for things like soft synths, effects and where you need the
> responsiveness of live input with minimal delay.
>
> The reason is because playing a soft synth live via a midi keyboard is just
> unplayable when you have say a hundred millisecond delay from playing a note
> until when you actually hear it. With a realtime kernel you can get very low
> latency and soft synths and the like become much more usable. For a daemon
> playing music I don't see how this would make much difference but as I say I'm
> not familiar with mpd.
>
> It seems you went down the right track though, one thing I might add is that
> if you followed the jack faq, you need to add yourself to the audio group to
> have realtime functionality for processes that you run. Or you could add the
> username that mpd runs as to limits.conf instead, however I'm not sure of the
> consequences of this.
> Hope this helps and the best of luck in your endeavour.
>
> Best regards
> Gavin

Thank you Gavin.  Do I need to prioritize both jack and mpd?  Anything else?

Since all I want to do is a straightforward playback of music via mpd,
I think using jack is only necessary so I can use its reporting
abilities to find out how real-time my system is.  Is that correct?

- Grant