[pulseaudio-discuss] Suggestions on how to support avoid-resampling on PulseEffects

[Arun Raghavan]

On Sat, 22 Sep 2018, at 10:03 PM, wellington wallace wrote:
> Hi PA developers!
> 
> As you can see here https://github.com/wwmm/pulseeffects/issues/288 there
> are users that would like to have avoid-resampling supported in
> PulseEffects(and I would like it too). But honestly I am out of good ideas
> about how to do this. At this moment I am using null sinks to do the audio
> routing and there is a Gstreamer pipeline that records from it. I can
> change the format and rate of the GStreamer pipiline to the ones used by
> the audio application being processed but as I can't do the same to the
> null sink it would be pointless. The resampling would happen anyway.
> 
> At this moment the only way I see to support avoid-resampling would be to
> reload the null sink with the new rate and format. But this is really
> annoying because as soon as I kill the null sink Pulseaudio will move the
> audio application back to the default device. It is not impossible to deal
> with this. But it may require major changes in the code.
> 
> Is reloading the null sink the only way to deal with this? It crossed my
> mind to try to make a custom null sink that could change these parameters
> on the fly. But besides the fact that Arch Linux packages do not have
> Pulseaudio developement headers I don't even know if it is possible to make
> any null sink that would accept this.

I have patches in the queue to enable reconfiguration for module-null-sink. https://gitlab.freedesktop.org/pulseaudio/pulseaudio/merge_requests/14

Should be easy enough to add a modarg like we have for ALSA to make it also just request support at module load time.

-- Arun