[pulseaudio-discuss] [PATCH 3/7] device-manager, filter-apply: don't reroute streams that have a filter

[Arun Raghavan]

On Tue, 2016-03-22 at 15:54 +0200, Tanu Kaskinen wrote:
> On Tue, 2016-03-22 at 15:41 +0200, Tanu Kaskinen wrote:
> > 
> > device-manager reroutes all streams whenever a new device appears.
> > When filter-apply has loaded a filter for some stream, the filter
> > device may not be what device-manager considers the best device for
> > the stream, which means that when an unrelated device appears,
> > device-manager may break the filtering that filter-apply had set up.
> > 
> > This patch changes filter-apply so that it saves the filter device
> > name to the stream proplist when it sets up a filter. device-manager
> > can then check the proplist when it does rerouting, and skip the
> > rerouting for streams that have a filter applied to them.
> > 
> > The proplist isn't cleaned up when the stream moves away from the
> > filter device, so before doing any decisions based on the
> > filter_device property, it should be checked that the stream is
> > currently routed to the filter device. It seemed simpler to do it this
> > way compared to setting up stream move monitoring in filter-apply and
> > removing the property when the stream moves away from the filter
> > device.
> > ---

My preference is to manage an ignore property that module-device-
manager can check, and have that managed within module-filter-apply. In
that way, all the behaviour related to module-filter-apply is
effectively encapsulated in that module, rather than leaking into
module-device-manager.

Thoughts?

-- Arun

> >  src/modules/module-device-manager.c | 14 ++++++++++
> >  src/modules/module-filter-apply.c   | 53 +++++++++++++++++++++++++++++++++++--
> >  2 files changed, 65 insertions(+), 2 deletions(-)
> > 
> > diff --git a/src/modules/module-device-manager.c b/src/modules/module-device-manager.c
> > index 1a0a53e..76363f3 100644
> > --- a/src/modules/module-device-manager.c
> > +++ b/src/modules/module-device-manager.c
> > @@ -649,6 +649,7 @@ static void update_highest_priority_device_indexes(struct userdata *u, const cha
> >  }
> >  
> >  static void route_sink_input(struct userdata *u, pa_sink_input *si) {
> > +    const char *filter_device;
> >      const char *role;
> >      uint32_t role_index, device_index;
> >      pa_sink *sink;
> > @@ -663,6 +664,12 @@ static void route_sink_input(struct userdata *u, pa_sink_input *si) {
> >      if (!si->sink)
> >          return;
> >  
> > +    /* If module-filter-apply has loaded a filter for the stream, let's not
> > +     * break the filtering. */
> > +    filter_device = pa_proplist_gets(si->proplist, "module-filter-apply.filter_device");
> > +    if (filter_device && pa_streq(filter_device, si->sink->name))
> > +        return;
> There should be a comment explaining the pa_streq() check.
>