Re: Setting Sample Rates
Re: Setting Sample Rates
- Subject: Re: Setting Sample Rates
- From: Jeff Moore <email@hidden>
- Date: Tue, 15 Jan 2002 11:31:26 -0800
on 1/15/02 1:08 AM, Douglas Wright <email@hidden> wrote:
>
As you said
>
before, flexibility is good for the driver writer, so why are you trying to
>
limit it to a predefined list of types? What about the soon to be released
>
scubafone input. How do we identify it if it comes out after we build our
>
apps?
It wouldn't be CoreAudio that would define these things. Both FireWire and
USB Audio have a specification for this sort of thing.
>
are DataSources only for inputs or for outputs too (DataSinks)?
Data source controls are available to both input and output. Note that this
is an optional feature, so you can't count on it being present for every
device or stream.
>
Where do you define that in the driver?
Data sources are a specialization of the normal IOAudioSelectorControl with
the subtype of kIOAudioSelectorControlSubTypeInput or
kIOAudioSelectorControlSubTypeOutput. They can be associated either with an
IOAudioEngine or with an IOAudioStream.
IOAudioSelectorControls include a mapping from the ID for the source to a
CFStringRef that is it's name.
All of this is documented here (assuming you have the December Developer
Tools Update installed):
/Developer/Documentation/Darwin/IOKit/DeviceDrivers/WritingAudioDrivers
--
Jeff Moore
Core Audio
Apple