On 22/01/2020 19:29, R.Wieser wrote:
> mm0fmf,
>
>> The error return value from most of those sound functions is not being
>> checked.
>
> :-) That doesn't mean I, in the course of trying to find the problem, didn't
> do that myself.    None of the functions returned a negative result.
>
>> Does the hardware you are using support 8000Hz sample rate?
>
> I have no idea.    The  "snd_pcm_hw_params_set_rate_near()" function seems
> to think so though (no negative result), "val" is unchanged.  My guess
> therefore is that it does.
>
>> Does aplay and arecord work with the sample rates you want to use?
>
> I tested aplay, and it it does. Even down to 4000.
>
> Just one question: Do you have a Raspberry Pi (3b+), and if so could you
> PLEASE test if you can reproduce my problem.
>
> I need to know if its just a (lack of) code problem, or if should replace my
> currently used software (ALSA, OS, anything else ?)
>
> Regards,
> Rudy Wieser
>
>
Sorry only a B+ and a Zero_W or I would have tried.

Maybe try the example programs linked on the ALSA API pages?

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