[pulseaudio-discuss] On-the-fly changing of sinks or sources in combine- and loopback-modules? Sound-distortions at the beginning of module-loopback?

[pl bossart]

>> >> 2. I also have a problem with sound distortions (mostly much higher
>> >> and "quicker" voice) several seconds after loading the
>> >> loopback-module (source is a bluetooth-headset and sink is my
>> >> soundcard). After some seconds the distortions disappear and
>> >> everything is fine. I found out that reducing the adjust_time
>> >> parameter of the loopback-module (I had to add adjust_time to
>> >> valid_modargs in the source code) also reduces the duration of the
>> >> distortions, but even at adjust_time=1 they remain for about 2
>> >> seconds (and pulseaudio uses much more CPU). Setting it to 0 doesn't
>> >> work at all.
>> >
>> >Sounds as if there is something wrong with the device speed. which
>> >causes PA to compensate by resampling things.
>>
>> So would it be possible to fix this? Do you need more info/some logs?
>
> Uh. this is tricky to fix. Not sure I can tell you anything that could
> fix this quickly for you. Somebody has to sit down with the hardware
> and really figure out what is going on, this is not really feasible
> remotely.

It could be that the initial variations of sample rate are too high,
and that causes audio issues with the resampling. This module
estimates the input and output sample rates, and I have seen in some
logs that the estimates can be somewhat off initially, e.g. 53kHz
instead of 48kHz. Can you provide a log of sample rate estimates? This
would help validate my theory.
Thanks
- Pierre