audio: properly restore audio volume on exit when mute is used

When you mute audio, mplayer is supposed to restore the volume controls
on exit. This affects when --softvol isn't used and the audio output
driver volume controls directly affect the system wide volume controls.

This wasn't done in some cases.

command.c

@@ -762,8 +762,7 @@ static int mp_property_mute(m_option_t *prop, int action, void *arg,
             return M_PROPERTY_DISABLED;
         if (!arg)
             return M_PROPERTY_ERROR;
-        if ((!!*(int *) arg) != mpctx->mixer.muted)
-            mixer_mute(&mpctx->mixer);
+        mixer_setmuted(&mpctx->mixer, *(int *) arg);
         mpctx->user_muted = mpctx->mixer.muted;
         return M_PROPERTY_OK;
     case M_PROPERTY_STEP_UP:

mixer.c

@@ -45,11 +45,36 @@ void mixer_reinit(mixer_t *mixer)
         mixer_setvolume(mixer, mixer->restore_vol_l, mixer->restore_vol_r);
         mixer->muted = muted;
     }
+    if (mixer->muted) {
+        // undo mixer_uninit()
+        mixer_setvolume(mixer, 0, 0);
+        mixer->muted = true;
+    }
     if (mixer->restore_balance) {
         mixer_setbalance(mixer, mixer->balance);
     }
 }
 
+// Called before the audio output is uninitialized.
+// Note that this doesn't necessarily terminate the mixer_t instance, and it's
+// possible that mixer_reinit() will be called later.
+void mixer_uninit(mixer_t *mixer)
+{
+    if (!mixer->ao)
+        return;
+    // The player is supposed to turn off the mute state when the player
+    // terminates. No other attempts at restoring the volume are done.
+    // One complication is that the mute state should survive audio
+    // reinitialization (e.g. when switching to a new file), so we have to be
+    // sure mixer_reinit() will restore the mute state.
+    if (mixer->muted) {
+        // avoid playing the rest of the audio buffer at restored volume
+        ao_reset(mixer->ao);
+        mixer_setmuted(mixer, false);
+        mixer->muted = true;
+    }
+}
+
 void mixer_getvolume(mixer_t *mixer, float *l, float *r)
 {
     ao_control_vol_t vol;
@@ -124,7 +149,7 @@ void mixer_setvolume(mixer_t *mixer, float l, float r)
             mixer->restore_vol_r = r;
         }
     }
-    mixer->muted = 0;
+    mixer->muted = false;
 }
 
 void mixer_incvolume(mixer_t *mixer)
@@ -162,12 +187,19 @@ void mixer_getbothvolume(mixer_t *mixer, float *b)
 
 void mixer_mute(mixer_t *mixer)
 {
+    mixer_setmuted(mixer, !mixer->muted);
+}
+
+void mixer_setmuted(mixer_t *mixer, bool mute)
+{
+    if (mute == mixer->muted)
+        return;
     if (mixer->muted) {
         mixer_setvolume(mixer, mixer->last_l, mixer->last_r);
     } else {
         mixer_getvolume(mixer, &mixer->last_l, &mixer->last_r);
         mixer_setvolume(mixer, 0, 0);
-        mixer->muted = 1;
+        mixer->muted = true;
     }
 }
 

mixer.h

@@ -42,12 +42,14 @@ typedef struct mixer_s {
 } mixer_t;
 
 void mixer_reinit(mixer_t *mixer);
+void mixer_uninit(mixer_t *mixer);
 void mixer_getvolume(mixer_t *mixer, float *l, float *r);
 void mixer_setvolume(mixer_t *mixer, float l, float r);
 void mixer_incvolume(mixer_t *mixer);
 void mixer_decvolume(mixer_t *mixer);
 void mixer_getbothvolume(mixer_t *mixer, float *b);
 void mixer_mute(mixer_t *mixer);
+void mixer_setmuted(mixer_t *mixer, bool mute);
 void mixer_getbalance(mixer_t *mixer, float *bal);
 void mixer_setbalance(mixer_t *mixer, float bal);
 

mplayer.c

@@ -714,10 +714,10 @@ void uninit_player(struct MPContext *mpctx, unsigned int mask)
     if (mask & INITIALIZED_AO) {
         mpctx->initialized_flags &= ~INITIALIZED_AO;
         current_module = "uninit_ao";
-        if (mpctx->edl_muted)
-            mixer_mute(&mpctx->mixer);
-        if (mpctx->ao)
+        if (mpctx->ao) {
+            mixer_uninit(&mpctx->mixer);
             ao_uninit(mpctx->ao, mpctx->stop_play != AT_END_OF_FILE);
+        }
         mpctx->ao = NULL;
         mpctx->mixer.ao = NULL;
     }
@@ -727,8 +727,6 @@ void uninit_player(struct MPContext *mpctx, unsigned int mask)
 
 void exit_player_with_rc(struct MPContext *mpctx, enum exit_reason how, int rc)
 {
-    if (mpctx->user_muted && !mpctx->edl_muted)
-        mixer_mute(&mpctx->mixer);
     uninit_player(mpctx, INITIALIZED_ALL);
 #if defined(__MINGW32__) || defined(__CYGWIN__)
     timeEndPeriod(1);
@@ -3124,8 +3122,7 @@ static void edl_seek_reset(MPContext *mpctx)
             mpctx->edl_muted = !mpctx->edl_muted;
         next_edl_record = next_edl_record->next;
     }
-    if ((mpctx->user_muted | mpctx->edl_muted) != mpctx->mixer.muted)
-        mixer_mute(&mpctx->mixer);
+    mixer_setmuted(&mpctx->mixer, mpctx->edl_muted || mpctx->user_muted);
 }
 
 
@@ -3153,8 +3150,7 @@ static void edl_update(MPContext *mpctx)
                    next_edl_record->stop_sec, next_edl_record->length_sec);
         } else if (next_edl_record->action == EDL_MUTE) {
             mpctx->edl_muted = !mpctx->edl_muted;
-            if ((mpctx->user_muted | mpctx->edl_muted) != mpctx->mixer.muted)
-                mixer_mute(&mpctx->mixer);
+            mixer_setmuted(&mpctx->mixer, mpctx->edl_muted || mpctx->user_muted);
             mp_msg(MSGT_CPLAYER, MSGL_DBG4, "EDL_MUTE: [%f]\n",
                    next_edl_record->start_sec);
         }