Re: Adding native audio support to ports

[adr <adr%sdf.org@localhost>]

On Thu, 1 Feb 2024, adr wrote:
> On Mon, 29 Jan 2024, adr wrote:
> >  Although it is a good idea to try to achieve the latency like in
> >  the alsa code in pcaudiolib (I did it already)
>
> Hum..., I've been reading dev/audio.c and it's clear that the water
> marks are not used as I expected.

Ok, now I see that I could use an audio block as a period (fragment)
, and set the hiwat to the number of periods (fragments). In
pcaudiolib is of not use because it's trying to achieve a fixed
latency which is the same the netbsd audio system will use to adjust
blocksize.

I've seen that the jack sun audio driver is fixing the number of
periods (-n) to 2 (hiwat). Nia, did you find problems making this
settable (higer values)? I'll try to make fluidsynth work with a
suitable latency (with the oss layer is too high, and I don't know
why, OSS_SNDCTL_DSP_SETFRAGMENT in ossaudio.c seems to be doing
the right thing). With jack the latency is reduced but I've problems
with performance (I think, I should debug it correctly). Any info
will be great for future hacking.

adr