[alsa-devel] Fixed latency between multiple channels

[Clemens Ladisch]

cuhl at eit.uni-kl.de wrote:
> I've read, that even with a realtime kernel the input-output latency
> varies with time - especially if USB is inbetween.

Yes, USB cam have a small but unknown delay between playback and capture.

> I expect to require a fixed latency between multiple ( I2S ) channels.

> So every channel's signal shall be exactly determined to its
> relative position with respect to the other channels, e. g. it shall be
> known inside the system which events occured simultanously.
>
> Likewise, the processed or generated signals shall be transferred to the
> outputs in a way, that they occur there with intended and modifiable
> relative latency to each other.

This is essentially a hardware problem.

Can't you just use a single device with many channels?


Regards,
Clemens