fix frame interval

src/audio.rs

@@ -79,6 +79,9 @@ struct DeckState {
     sample_rate: u32,
     read_pos: usize, // byte index into pcm (always even)
     cue_pos: usize,
+
+    /// Track last VU update time to rate-limit updates
+    last_vu_update: std::time::Instant,
 }
 
 impl DeckState {
@@ -90,6 +93,7 @@ impl DeckState {
             sample_rate: 44100,
             read_pos: 0,
             cue_pos: 0,
+            last_vu_update: std::time::Instant::now(),
         }
     }
 }
@@ -220,11 +224,18 @@ fn engine_thread(cmd_rx: Receiver<AudioCmd>, status_tx: Sender<AudioStatus>) ->
                         deck: ds.id,
                         position: pos,
                     });
-                    let _ = status_tx_cb.try_send(AudioStatus::Vu {
-                        deck: ds.id,
-                        l: vu_l,
-                        r: vu_r,
-                    });
+
+                    // Rate-limit VU updates to ~60Hz (16ms) to reduce CPU usage
+                    // while still providing smooth updates during playback
+                    let now = std::time::Instant::now();
+                    if now.duration_since(ds.last_vu_update) >= std::time::Duration::from_millis(16) {
+                        let _ = status_tx_cb.try_send(AudioStatus::Vu {
+                            deck: ds.id,
+                            l: vu_l,
+                            r: vu_r,
+                        });
+                        ds.last_vu_update = now;
+                    }
                 }
             })
             .register()?; // Connect the stream with F32LE stereo format