Re: [RFC PATCH 0/4] Add support for detection

[Jaroslav Kysela <perex@xxxxxxxx>]

On 16. 10. 24 15:02, Amadeusz Sławiński wrote:
> There are some scenarios when using DSP where one may want to have
> partially active stream and fully enable it after some event occurs.
>
> Following patchset adds new "detect" state to ALSA state machine to
> allow waiting for condition to occur before fully starting a stream. In
> further patches the state is propagated through ASoC components to allow
> them to handling the state as necessary.
>
> Main goal of this patchset is to allow handling scenarios like keyphrase
> detection - where DSP analyses incoming signal and wakes userspace to
> consume stream only when keyphrase is detected.
>
> I'm sending this as RFC so we can discuss if this is the way to go or if
> there is perhaps another preferred way of adding such interface.
> Userspace part of implementation is available at
> https://github.com/amadeuszslawinski-intel/alsa-lib/tree/rfc_detect

It looks like a complex extension with a low benefit. We have already layer 
which can signalize stream readiness - an element in the control API. PCM 
driver may just return silence samples when the condition is not met for 
security reasons.

				Jaroslav

--
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.