Subject: Re: [linux-audio-dev] LAAGA proposal, part ??
From: Abramo Bagnara (abramo_AT_alsa-project.org)
Date: Fri Jun 08 2001 - 09:48:34 EEST
Paul Davis wrote:
>
> >> Ardour has already been ported to something very close to this
> >> model. I have not yet added metering, and input monitoring is deeply
> >> problematic but everything else works.
> >
> >If you read my recent message about this you will see that with "flow"
> >concept this can be solved elegantly.
>
> 1) metering is a problem because in ardour there are several objects
> that read the meter, and thus it should really be computed only once.
>
> there are several problems here.
>
> first of all, the actual value(s) computed by the meter are not
> audio data, but a different type. the API under discussion does
> not include a builtin method for transferring such data around.
>
> second, peak meters need to be reset periodically. in ardour,
> the meters are reset whenever they are read, which provides the
> correct behaviour. if you implement metering via a separate client,
> this is not possible to do, since many other clients may want
> to read the current peak value. so, defining the reset interval
> (which is quite different than the hold interval used by a display)
> is tricky to do.
>
> finally, because for input metering you need to be able to connect
> an "input" to an "input", there is an inherent problem with any
> system that ensures proper port polarity when connections are made.
> output metering is obviously easy to do.
>
> 2) input monitoring is deeply problematic because first of all you
> have to do the same kind of "connect an input to an input", and
> then secondarily, the concept simply makes no sense for the
> majority of ports that would exist in a running system. the idea
> of "turn on input monitoring" for a port that is the output of a
> particular object is generally nonsensical - it to make sense only
> if the port corresponds to a physical connection.
Then, no, you've not read my message: to connect read flow on an input
port if perfectly fine.
-- Abramo Bagnara mailto:abramo_AT_alsa-project.orgOpera Unica Phone: +39.546.656023 Via Emilia Interna, 140 48014 Castel Bolognese (RA) - Italy
ALSA project http://www.alsa-project.org It sounds good!
This archive was generated by hypermail 2b28 : Fri Jun 08 2001 - 11:58:57 EEST