[LAU] Problems with sample rate and recordings (Mackie onyx > 1640-i < Firewire > Debian )

Chris Caudle chris at chriscaudle.org
Tue Mar 3 22:46:51 UTC 2015


On Tue, March 3, 2015 3:22 am, Ralf Mardorf wrote:
>>On 03/03/2015 01:03 AM, Chris Caudle wrote:
>>> for nearly every device the driver should be able to set the
>>> sample rate
>
> But by what way can the sample rate be set?

By using the snd_pcm_hw_params_set_rate_near () ALSA function.  That is
what jack2 uses.

http://www.alsa-project.org/alsa-doc/alsa-lib/group___p_c_m___h_w___params.html#ga39124280d06ce63092a77e3f25ddd6ee

> I've got PCI cards were jackd is able to set all available sample
> rates, but for my PCIe card just some sample rates can directly be set
> by jackd, for some sample rates I need to do it by alsamixer, before I
> start jackd.

That is very odd.  Glancing at the alsamixer source I do not see any
explicit sample rate controls, it appears to just get a list of supported
controls from the card driver.  I don't know why alsamixer would be able
to find a sample rate control when hw_params_set_rate_near() did not work
properly.
You would probably need to discuss with the developer of the driver for
that particular card.

-- 
Chris Caudle




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