Re: [linux-audio-dev] CSL-0.1.2 Release

[Stefan Westerfeld <stefan space twc de>]

   Hi!

On Wed, Jun 06, 2001 at 07:31:22PM -0400, Paul Davis wrote:
> In message <20010607002228 10931 space twc de>you write:
> >CSL-0.1.2 - the Common Sound Layer - has been released.
> >
> >The scope of CSL can roughly be summarized as:
> >  Helping all applications out there that currently contain a
> >  variety of platform specific notoriously non-portable audio code.
> >
> >On the one hand, CSL provides sufficient abstraction of platform specific
> >details, where we took extreme care to maintain full-fledged access to
> 					^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >the features offered by the APIs being wrapped, such as:
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> I consider this to be a serious design error.
> 
> Every (commercial) player in the computer audio world has apparently
> learnt the following lessons about audio APIs:
> 
>     * use a single common audio data format
>     * use a callback model
>     * remove almost all hardware related concepts from the API
> 
> Wrapping a Hardware Abstraction Layer (HAL) like OSS or ALSA in what
> is really just another HAL with the same semantics but different
> function names doesn't move us forward. Instead, it just provides
> developers with yet another choice to make, and continues to force
> them to work with details of audio that they should not have to care
> about.

I think you are not seeing an important point here:

 * CSL is meant for some applications (not all applications)
 * VST-like APIs are an entierly different thing

I do agree with you that for music style low latency applications, you want
a callback driven API with a common data format. Such as the flow system
aRts uses inside the sound server. Using CSL and artsd, both can peacefully
coexist. You can

1. use your callback driven low latency effects, synthesis, hd-recording with
the aRts flowsystem inside the artsd server process

2. use legacy or very simple applications such as quake, mpg123, window manager
sounds,... outside the server, and just inject their input into the flow
system via CSL

I think neither applications of type 1. nor applications of type 2. will cease
to exist anytime soon, so having both types of APIs available is definitely
good.

   Cu... Stefan
-- 
  -* Stefan Westerfeld, stefan space twc de (PGP!), Hamburg/Germany
     KDE Developer, project infos at http://space.twc.de/~stefan/kde *-