[alsa-devel] spdif input, source synchronous?

Clemens Ladisch clemens at ladisch.de
Thu Jan 24 12:49:43 CET 2013

Rafal Powierski wrote:
> ... ALC886 SPDIF input.
> The test results show that the input is not "source synchronous"
> It seams that my HDA clock is a bit slower then definition ( about -10ppm)
> Therefore resampling starts below -10ppm
> It probably means that when spdif signal is 0ppm, about 10ppm of samples are missing.

And real S/PDIF inputs probably are all over the map ...

> Is this a bug? or it is planed like this?

The HDA specification describes source synchronous streams, but does
not mandate them.

Apparently, the ALC886 does not support source synchronous streams.
A quick Google search shows only the WM8850 (which also has a real
sample rate converter).


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