audio decoding

player.rkt

@@ -30,6 +30,7 @@
     (define closing #f)
     (define pause #f)
     (define repeat-state 'no-repeat)
+    (define volume 100.0)
     
     (define ao-handle #f)
     (define flac-handle #f)
@@ -64,6 +65,8 @@
             )
           )
         )
+      (when (not (= (ao-volume ao-handle) volume))
+        (ao-set-volume! ao-handle volume))
       )
 
     (define (start-play-time-updater)
@@ -274,6 +277,15 @@
       (stop-and-clear)
       )
 
+    (define/public (set-volume! percentage)
+      (set! volume percentage)
+      (unless (eq? ao-handle #f)
+        (ao-set-volume! ao-handle volume))
+      )
+
+    (define/public (get-volume)
+      volume)
+
     (define/public (next)
       (if (= (send pl length) 0)
           #f