Re: Making OSSO default JACK option

On 8/20/24 18:33, Florian Walpen wrote:
> Hi Meka,
> Nice to hear that it's working! The option is called SOSSO BTW, but OSSO(BUCO)
> would sound yummy too. Just to clarify, the high DSP busy percentage was
> probably not due to CPU load, but caused by timing difference between playback
> and recording channel IO, and OSS buffer restrictions.

Ah, I came from a trip recently and I'm still tired, so apologies for 
the wrong name :D As I read some articles, DSP percentage represents 
processing+waiting time compared to time corresponding to the buffer 
size. So naturally, for the same DSP percentage, lower the CPU usage => 
higher the waiting.

> One of the achievements in the new JACK sosso backend is the decoupling of
> JACK period from the OSS processing interval. The mmap'ed IO and a rigorous
> progress measurement let JACK and OSS process at their own pace, without a
> huge buffer that hurts latency. This way it also gets rid of the timing
> dependencies between playback and recording.
>
> With some assistance from the kernel it should be possible to simplify the
> progress measurements and implement the decoupling method in other sound
> servers and applications on FreeBSD. We'll see how that goes.
I do intend to learn how mmaped IO is done, at least just enough to 
understand what you did for SOSSO. I guess before that I'm not in a 
position to understand it all.
> As for JACK, I'd like to get some more feedback before we turn SOSSO into the
> default option. But I did hear you ;-)
I see my Subject: is wrong on many levels :o) I meant "making it default 
in the future" but the fatigue got me. Anyway, yes, I didn't mean jump 
on it this instance, it's just a bad wording.
> Good luck and success with your album recording!

We do intend to make it CC licensed (just like the first album), so it 
might be good showcase for FreeBSD in the future. We'll see.

Regards,
meka