Subject: Re: [linux-audio-dev] PortAudio
From: Benno Senoner (sbenno_AT_gardena.net)
Date: Wed Jun 27 2001 - 11:20:22 EEST
On Wed, 27 Jun 2001, you wrote:
> ----- Original Message -----
> From: "Paul Davis" <pbd_AT_Op.Net>
>
> > Phil, thanks for the pointer to PA. I'm glad to see that you've also
> > adopted a callback model. PA looks quite pleasant to use and not too
> > far from part of what LAAGA is aiming at. However, the primary goal of
> > LAAGA is to facilitate inter-application data exchange rather than
> > just providing a simpler (more portable) layer for interacting with
> > audio h/w. Do you have any thoughts on that aspect of things?
>
> Yes. PortAudio and LAAGA are targetting different requirements. PortAudio
> was meant to be a simple as possible interface to other audio APIs such OSS
> and WMME. Inter-application data exchange was seen as something very useful,
> but beyond the scope of PortAudio.
>
> But I could imagine two ways in which PortAudio and LAAGA could complement
> each other. LAAGA could call PortAudio for access to actual audio HW. That
> would make LAAGA more easily portable to other platforms. Or there could be
> an implementation of PortAudio that called LAAGA. Then existing apps that
> used PortAudio would be able to connect to each other via LAAGA.
Yes I think that writing such a backend/wrapper for PortAudio would not be
that difficult.
Regarding the portability of LAAGA, it's an API that can launch/mangage
multiple clients (processes/threads) which communicate each other trough some
sort of IPC.
This should make it quite portable across UNIX enviroment.
With a few tweaks it would probably be possible to run it on Windows too,
but in this case the OS does not cooperate that well in terms of low latency so
it would not be that useful.
You know, under Windows to get low latencies under Windows you need to
bypass the OS coding at a very low-level (see Steinberg with ASIO, or
gigasampler that runs the DSP code in kernel mode in order to get these low
latencies, ditto for Seersystems Reailty)
This is definitively the way we want to avoid on Linux and thanks to the
exceptional work of the lowlatency guys, we can afford to run all our DSP
stuff completely in userspace without sacrificing latency.
>
> BTW, is this linux-audio-dev mail list just for LAAGA, or is it for Linux
> audio development in general?? I don't want to be off-topic if I have OSS or
> ALSA or low-latency-patch questions. Thanks.
You are right, every thing that has to do with linux and audio is on-topic here.
:-)
cheers,
Benno.
http://www.linuxaudiodev.org The Home of Linux Audio Development
This archive was generated by hypermail 2b28 : Wed Jun 27 2001 - 10:36:03 EEST