On Tue, Aug 26, 2014 at 8:45 AM, Grant <emailgrant@gmail.com> wrote:

>>> I have a USB DAC that can only handle 16/44.1 as input and output. I
>>> think ALSA will resample everything to 16/44.1 automatically, but I'd
>>

>> I think what I am saying is that for most cases the sample rate of your
>> audio IF doesn't matter. So adding resampling to everything doesn't make
>> sense... maybe try without first.
>
> I think you're saying that the ALSA resampler won't be used if the
> upstream application does the resampling itself. Is that correct?
> How can I find out if ALSA is the one resampling in a particular
> scenario?

Is there any way to find out if this is happening? Do some
applications really do this?

depends on the device the application opens.

If you tell it to open a device with a name like "hw:N" or "hw:CARDNAME" then ALSA will offer only the capabilities present in the audio hardware. If you open it with a name like "plughw:N" or "plughw:CARD" then ALSA will do everything it can to honor the format, sampling rate etc. asked for by the application (including resampling, channel multiplexing etc.).