ajout oscillo

Appli/Core/Inc/audio_effects.h

@@ -18,7 +18,8 @@ extern "C" {
  * octaveur -> egaliseur -> overdrive -> saturation -> echo -> reverberation. */
 typedef struct
 {
-    bool audio_on_off;
+    bool  audio_on_off;
+    float master_volume;   /* volume general en sortie de chaine, 0.0 a 1.0 */
     FxOctaverParams octaver;
     FxEqualizerParams equalizer;
     FxOverdriveParams overdrive;