Re: [Alsa-user] "plug" refuses to play audio at normal sample rates

[Adam N. <a.n...@sh...>]

> Well, as far as I know LADSPA - it's very difficult, if not impossible,
> to not detect sample rate correctly.
> 
> Did you look into the plugin source ?

I've had a look through it, but I can't see where the code is that does
sample rate conversion.

> Can it be that ALSA calls the plugin initialization routine with
> wrong sample rate ?
> 
> Can it be that ALSA calls the plugin initialization routine only once
> and not on each sample rate change ?

Since it works properly with unusual sampling rates (like 60kHz) I don't
think it's an ALSA issue.  It only fails when using a sampling rate
directly supported by the underlying hardware - in that case it still
needs to do resampling, but for whatever reason the audio is *not*
resampled and playback fails.

At some point there is a sample rate check, and instead of checking what
sample rates the next *plugin* in the chain supports, the code
incorrectly checks what sampling rates the *hardware* supports.  The
hardware supports four different sample rates, the plugin only supports
one - so sometimes the audio isn't being resampled when it should be.

Cheers,
Adam.