Re: real-time threaded IO with low latency (audio)

Paul Barton-Davis (pbd@Op.Net)
Sat, 24 Jul 1999 14:34:29 -0400


>> MIDI sequencing is not a problem, or rather, its certainly not a deep
>> problem. Audio is, however.
>
>MIDI IS a problem, unless you accept that some notes are delayed by a
>few ms every now and then.

the KURT patches can fix this to provide microsecond accuracy from
user space, on the standard kernel.

>> >"Cool" Windoze/Mac DAW style
>>
>> These all rely on external hardware if they do the job
>> right.
>
>I disagree. It's just a matter of using the right kind of OS so that the
>resources at hand can be used properly.

you're not disagreeing with me :) the reason why the mac/windows DAW's
use external hardware is because the OS they "run on" can't do the
right thing.

but note: its possible on both those systems for an application to own
the machine in the same sense that RTL does. despite this, nobody has
yet managed to produce an audio application without external hardware
for those OS's that doesn't have latency problems. is it just that
steinberg, creamware etc. are stupid, or is there something more
important going on ? i mean, you really can hard real time as an
application on the macos (even though its not a very friendly thing to
do to the system), and yet ...

[ kyma ]

>(What I meant was thinking about was actually the system that's running
>on that external box for example. They all run some kind of OS, with
>APIs and all.)

i don't think that the Kyma/Capybara offers any API to the user.

>What would you have against Audiality (or RTL or whatever it will run on
>in the end) as an end user? Apart from it all being open source, a dual
>Alpha AXP or Xeon is a nice machine to play with when not using it for
>recording... :-)

mostly because quasimodo is designed to do the same things that you're
talking about, its already written and running, and i'm committed (for
now) to a non-RTL solution to the problems. quasimodo has already been
ported to IRIX, a Solaris port is under way and a BeOS port is under
discussion. for these reasons alone, reliance on RTL isn't very
attractive.

--p

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/