Re: New QT possibly breaks 3DMixer OpenAL
Re: New QT possibly breaks 3DMixer OpenAL
- Subject: Re: New QT possibly breaks 3DMixer OpenAL
- From: William Stewart <email@hidden>
- Date: Thu, 6 May 2004 19:33:48 -0700
Ah... in the process of writing about this.
The new QT release includes a major overhaul of the 3DMixer that was
done for OpenAL. This primarily includes a considerable number of
substantial performance improvements in this code (in some cases the
performance improvement is over 50% improvement).
We've been preparing a document that describes how to code both for
this version of the 3DMixer (its component version is 2.0), versus the
previous versions (1.3)... We sought not to break any existing
functionality with the 3DMixer in the process of doing this of course.
I believe however, there are some discrepancies with the V1 version of
the 3DMixer (this is created by using the component type of):
ComponentDescription k3DMixerDesc = { kAudioUnitComponentType,
kAudioUnitSubType_Mixer, kAudioUnitID_3DMixer, 0, 0 };
We've been advising people for quite some time not to use the V1 Audio
Units (so, to create a V2 version of the 3DMixer you should be doing):
ComponentDescription k3DMixerDesc = { kAudioUnitType_Mixer,
kAudioUnitSubType_3DMixer, kAudioUnitManufacturer_Apple, 0, 0 };
I don't believe there are any problems with the V2 case (and if this is
the problem, then I'd need more details). Are you running this with
OpenAL or separately.. We've been checking back changes into the OpenAL
code base to fix reported issues, so if it is OpenAL you should make
sure you are using the latest version from their repository.
Sorry if that's a bit vague, but I need more details to give you a
better answer.
Bill
On 06/05/2004, at 7:11 PM, Brian Barnes wrote:
>
I posted this to the OpenAL list, but I'm sure the engineer
>
responsible probably is on this list, also.
>
>
First off, I'm not sure when it broke, but the new 3DMixer OpenAL
>
(from Apple) no longer does distance or panning volume changes (all
>
sounds are at max volume.)
>
>
I think it might be the new QT that came at the same time as iTunes
>
4.5, but I was working on other parts of the system for a while so I
>
never noticed until a day or so ago.
>
>
I'm the guy that pointed out the precision problem when the new OpenAL
>
first came out, then that was fixed, and now a similiar problem is
>
back, and I was wondering if something put in OpenAL to work around
>
that bug is now interfering when it got fixed in the mixer. My
>
business is guess work, if you can't tell :)
>
>
Just wondering if the core audio packages -- and especially the 3D
>
mixer -- were changed at all, or if anybody has tested OpenAL past the
>
simple test programs (I can supply a program that displays the
>
problem.)
>
>
This *could* be my problem, but I haven't changed that code so I'm
>
looking here first ....
>
>
Thanks ...
>
>
[>] Brian
>
_______________________________________________
>
coreaudio-api mailing list | email@hidden
>
Help/Unsubscribe/Archives:
>
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
>
Do not post admin requests to the list. They will be ignored.
>
>
--
mailto:email@hidden
tel: +1 408 974 4056
________________________________________________________________________
__
Culture Ship Names:
Ravished By The Sheer Implausibility Of That Last Statement
I said, I've Got A Big Stick [OU]
Inappropiate Response [OU]
Far Over The Borders Of Insanity And Still Accelerating [Eccentric]
________________________________________________________________________
__
_______________________________________________
coreaudio-api mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
Do not post admin requests to the list. They will be ignored.