uaudio patch, capabilities

Alexander Leidinger Alexander at Leidinger.net
Sun Mar 13 05:03:54 PST 2005


Mathew Kanner <mat at cnd.mcgill.ca> wrote:

>> I expected that only one sampling rate (when discrete) or
>> one sampling rate range (when continuous) must be set in caps.
>>
>> I guess that there are two solutions.
>> 1) use only one sampling rate or rage, neglect others.
>> 2) select one rate along a speed of a sound source
>>          when the channel is initialized.
>>
>> When I challenged it slightly, I aimed at 2).
>> It had no problem that I changed the caps at ua_chan_init() in uaudio_pcm.c.
>
> 	Hi,
> 	I'm not sure I know exaclty what you mean, but there were

I think he means:
The audio device doesn't supports a range, it only supports discrete
sampling rates: 44100, 48000 and 96000. I'm not sure what the second
proposal is, but my proposal is (without looking at any code, since I don't
have much time ATM) to provide the posibility to specify multiple
capabilities. So if the device is able to 22500 and 48000 but not 44100, it
should have 2 discrete sampling rates set in the capabilities.

Yes, this is an example out of the blue, I don't know if the capabilities
struct only allows fixed discrete sampling rates in the given range, or if a
range means that any sampling value in between min and max are allowed, I
also don't know if it's possible to have audio hardware which only supports
22500 and 48000, but not 44100. So depending on the reality our proposals
may be moot. :-)

Bye,
Alexander.

-- 
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