Re: HAL Devices and Streams (with QuickTime)
Re: HAL Devices and Streams (with QuickTime)
- Subject: Re: HAL Devices and Streams (with QuickTime)
- From: Lieven Dekeyser <email@hidden>
- Date: Fri, 18 Jan 2002 20:45:20 +0100 (CET)
>
> I dunno what they are exactly, but the name "HAL Audio" makes me think
>
> it's something like the OutputAudioUnit... can't you set the AudioDeviceID
>
> of that component? If so, you can get the list of availiable devices using
>
> AudioHardwareGetProperty...
>
>
>
Changing the current HAL Audio device to a different device is not the
>
problem. I need QuickTime to be able to access multiple devices at the same
>
time. For example, output one QuickTime movie to "USB Audio" and another to
>
"Built-In", or another to "VXPocket". If FindNextComponent and
>
GetComponentInfo can't see all the available options, then I can't set a QT
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Media track to the desired output using MediaSetSoundOutputComponent.
>
>
Do you think MediaSetSoundOutputComponent would accept a device from the
>
AudioHardwareGetProperty list? I assume MediaSetSoundOutputComponent only
>
accepts options from the "sheltered" FindNextComponent list. If I'm wrong,
>
it would be great! :)
I'm pretty sure MediaSetSoundOutputComponent would accept an
AudioDeviceID, but maybe you can set some kind of parameter for the "HAL
Audio" OutputComponent to the AudioDeviceID of your choice... Using
different devices would be as simple as creating instances of the HAL
Audio component and setting the AudioDeviceID parameter of each of these
instances.
This is all speculation based on how the AudioUnits (which are in
fact components of type kAudioUnitComponentType) work. I have no
idea of how these SoundOutputComponents work...
can anyone confirm or deny all this?
--Lieven