mmdevice: reset gain when the volume is changed from outside

modules/audio_output/mmdevice.c

@@ -280,6 +280,10 @@ vlc_AudioSessionEvents_OnSimpleVolumeChanged(IAudioSessionEvents *this,
     msg_Dbg(aout, "simple volume changed: %f, muting %sabled", vol,
             mute ? "en" : "dis");
     EnterCriticalSection(&sys->lock);
+    /* If the user ask to lower the volume, there is no need to amplify
+     * anymore. */
+    if (vol < 1.0f)
+        sys->gain = 1.0f;
     WakeConditionVariable(&sys->work); /* implicit state: vol & mute */
     LeaveCriticalSection(&sys->lock);
     (void) ctx;