Re: [9fans] audio standards -- too many to choose from

["Roman V. Shaposhnik" <rvs@sun.com>]

On Wed, 2009-08-12 at 17:36 +0200, hiro wrote:
> > This sounds like exactly the kind of thing one wants
> > from an audio driver for playback. For recording things
> > get slightly more complicated.
>
> What exactly do you mean?

Now that I understand what Tim is trying to do my original
concern makes no sense. Sorry for this little bit of noise.

>
> > Even for playback if you want to do passthrough (via
> > SPDIF or some such) things get slightly more complicated.
> > Of course, one can disregard passthrough as not
> > being an audio at all, but rather a datalink issue.
>
> What's so special about things like SPDIF?

Two things: the data traveling over the link can be any data, not
just some form of PCM (it can be AC-3, it can be DTS, it can even
be MP3). In that respect the audio card acts as a pass-through
device. It is not really supposed to do anything with the
data. And that brings us to the second point -- the pass-through
APIs can be as ugly as hell, depending on the type of the device
(follow the link to the MPlayer docs I provided in this thread).

> Why would it be not suitible for the kernel audio driver?

Because it has very little to do with the PCM audio, and that's
what the driver discussed in this thread was supposed to be all about.
Now, I'm not saying that there's shouldn't be a special driver just for
pass-through type of functionality, all I'm saying is that
lumping this functionality together with the PCM one would
confuse things.

> For me it's clearly an audio and
> not a datalink issue, but perhaps I have only limited use cases.

Perhaps, everywhere in this thread I should've prefixed the word
audio with "some form of PCM".

Thanks,
Roman.