[pulseaudio-discuss] [PATCH 2/2, v2] loopback: Reset sink input rate when source or sink changes

[Tanu Kaskinen]

On Mon, 2017-04-10 at 16:27 +0200, Georg Chini wrote:
> On 10.04.2017 16:23, Tanu Kaskinen wrote:
> > On Sat, 2017-04-08 at 20:34 +0200, Georg Chini wrote:
> > > If source or sink are changed, the current sink input rate may be different
> > > from the default rate. Switch sink input rate back to default to avoid the
> > > influence of the previous combination of source and sink.
> > > ---
> > >   src/modules/module-loopback.c | 18 +++++++++++++++---
> > >   1 file changed, 15 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/src/modules/module-loopback.c b/src/modules/module-loopback.c
> > > index 2242c62c..535c27d2 100644
> > > --- a/src/modules/module-loopback.c
> > > +++ b/src/modules/module-loopback.c
> > > @@ -639,11 +639,18 @@ static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
> > >   
> > >       /* Send a mesage to the output thread that the source has changed.
> > >        * If the sink is invalid here during a profile switching situation
> > > -     * we can safely set push_called to false directly. */
> > > -    if (u->sink_input->sink)
> > > +     * we can safely set push_called to false directly.  Also, the current
> > > +     * sampling rate may be far away from the default rate if we are still
> > > +     * recovering from a previous source or sink change, so reset rate to
> > > +     * default before moving the source. If the sink is not valid, only
> > > +     * update the sink input sample spec.*/
> > > +    if (u->sink_input->sink) {
> > >           pa_asyncmsgq_send(u->sink_input->sink->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_SOURCE_CHANGED, NULL, 0, NULL);
> > > -    else
> > > +        pa_sink_input_set_rate(u->sink_input, u->source_output->sample_spec.rate);
> > > +    } else {
> > >           u->output_thread_info.push_called = false;
> > > +        u->sink_input->sample_spec.rate = u->source_output->sample_spec.rate;
> > > +    }
> > 
> > pa_sink_input_set_rate() does other things too than just set
> > sample_spec.rate. I think you should always call
> > pa_sink_input_set_rate(), but since pa_sink_input_set_rate() currently
> > doesn't expect to be called in the middle of a move, it needs to be
> > fixed first.
> > 
> 
> I don't understand why it should not be enough to just set the sink 
> input rate.

Did you look at the code in pa_sink_input_set_rate()? It updates
thread_info.sample_spec.rate, calls pa_resampler_set_input_rate() and
sends a subscription event. Do you think it's ok to skip these things?

> This is also what is done before the sink input is put, so it should be 
> sufficient.

Which code are you referring to? Searching for "sample_spec.rate = " in
module-loopback.c doesn't yield any results except the two assignments
you added in this patch.

-- 
Tanu

https://www.patreon.com/tanuk