mixer: support native audio driver mute

Make mixer support setting the mute attribute at audio driver level,
if one exists separately from volume. As of this commit, no libao2
driver exposes such an attribute yet; that will be added in later
commits.

Since the mute status can now be set externally, it's no longer
completely obvious when the player should automatically disable mute
when uninitializing an audio output. The implemented behavior is to
turn mute off at uninitialization if we turned it on and haven't
noticed it turn off (by external means) since.

1 files changed, 2 insertions, 0 deletions

diff --git a/mixer.h b/mixer.h
index c1903750f1..efeb62856f 100644
--- a/mixer.h
+++ b/mixer.h
@@ -31,6 +31,8 @@ typedef struct mixer {
     bool softvol;
     float softvol_max;
     bool muted;
+    bool muted_by_us;
+    bool muted_using_volume;
     float vol_l, vol_r;
     /* Contains ao driver name or "softvol" if volume is not persistent
      * and needs to be restored after the driver is reinitialized. */