Re: Actual Stream vs. Physical Stream ?
Re: Actual Stream vs. Physical Stream ?
- Subject: Re: Actual Stream vs. Physical Stream ?
- From: Jeff Moore <email@hidden>
- Date: Wed, 19 Dec 2001 14:32:15 -0800
on 12/19/01 12:46 PM, Jim Dolan <email@hidden> wrote:
>
Another confusing thing is that the actual sample rate on my iMic device
>
comes back as 0.0 - yet the only rate that I can plug into the descriptor is
>
44100 - I get an error otherwise. I thought any rate was valid?
The device has the option of disallowing some rates at its discretion.
The driver provides the necessary information to the HAL about what range of
rates it truly can handle, but the HAL doesn't re-export that info just yet.
>
I notice
>
that Daisy always uses 44.1 for actual and 48 for physical devices that
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return 0.0 for a rate. Is it safe to assume all devices will work with those
>
settings?
This is just a hack I put in a while ago to allow me to just change the
sample rate on a particular USB device I was testing with once upon a time.
>
How do I really know what nominal rate to use?
If the device isn't recommending a rate, you should go with whatever rate
your app is most comfortable with, bearing in mind that the device might not
let you use that rate.
--
Jeff Moore
Core Audio
Apple