Re: AUGraph stream format problems
Re: AUGraph stream format problems
- Subject: Re: AUGraph stream format problems
- From: James Coker <email@hidden>
- Date: Mon, 6 Oct 2003 17:33:31 -0600
On Monday, October 6, 2003, at 04:19 PM, William Stewart wrote:
AUGraph doesn't make these decisions.
The errors are being returned by the AU you are connecting too (the
connection semantics are enforced by the AU - ie. the connection needs
to have the same format from output to input - if that format is
invalid then the connection will return an error). Its left to the
user of the graph to ensure that the connection will be valid and to
deal with it when it isn't.
Ok, I grok that.
The next bit is a little confusing:
We modified this behaviour between Jaguar and Panther given the
discussions we'd had about AU's and format negotiation (ie. can't
generally reset formats if the AU is initialized) - so the AUGraph
code's order of operations was modified to reflect this semantic.
Thus, now, the AUGraph will *not* initialize an AU until it is
involved in a connection, and it will initialize the AU *after* the
connection is made.
Does 'now' mean AUGraph in Jaguar, or in Panther?
Obviously, as a connection can involve both input and output sides,
this is not foolproof. Also, if the graph is running, this
connection/initialization will be made on the render thread -
generally not a good idea.
So the general advise is, make sure the formats are correct and the AU
is initialized before connecting it to a playing graph. (That also
allows you to determine if the AU can become a member of the graph at
the location, etc, you want it to be).
This seems contradictory with the statement above about AUGraph. So I
should check the I/O bus formats, then init the AU, then add to the
graph?
Jim
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