fix&feat: hiển thị tools chỉnh sửa audioclip

app/core/sub_tab_dsp.py

@@ -31,6 +31,57 @@ class SubTabDSPEngine:
         gain = target_amplitude / max_amplitude
         return y * gain
 
+    @staticmethod
+    def apply_volume_automation_envelope(y: np.ndarray, sr: int, nodes: list) -> np.ndarray:
+        """
+        Applies a user-drawn volume automation envelope onto an acoustic signal NumPy array.
+        nodes: A list of point dictionaries, e.g., [{"time": 0.0, "db": 0.0}, {"time": 2.5, "db": -12.0}, ...]
+        """
+        if not nodes:
+            return y
+            
+        # Sort envelope nodes chronologically by time axis
+        nodes = sorted(nodes, key=lambda x: x["time"])
+        
+        # 1. Map node variables into distinct coordinates arrays
+        node_times = np.array([node["time"] for node in nodes])
+        node_dbs = np.array([node["db"] for node in nodes])
+        
+        # Hard-clamp boundary constraints matching the operational floor [-30.0dB, +3.0dB]
+        node_dbs = np.clip(node_dbs, -30.0, 3.0)
+        
+        # 2. Evaluate absolute timeline timestamps for every index position inside the signal array
+        total_samples = len(y)
+        sample_times = np.arange(total_samples) / sr
+        
+        # 3. Linearly interpolate localized decibel thresholds across every single sample step
+        # Handle edge cases for interpolation: if sample_times is outside node_times range,
+        # np.interp uses the first/last value of node_dbs.
+        interpolated_dbs = np.interp(sample_times, node_times, node_dbs, left=node_dbs[0], right=node_dbs[-1])
+        
+        # 4. Map logarithmic values into standard linear gain scale arrays
+        linear_gains = 10.0 ** (interpolated_dbs / 20.0)
+        
+        # 5. Multiply the raw amplitude vector array by the linear gain modifier mask
+        return y * linear_gains
+
+    @staticmethod
+    def pitch_shift(y: np.ndarray, sr: int, n_steps: float) -> np.ndarray:
+        """
+        Shift the pitch of an audio signal by a specified number of semitones.
+        
+        Args:
+            y: Input audio signal
+            sr: Sample rate
+            n_steps: Number of semitones to shift (positive = higher pitch, negative = lower pitch)
+            
+        Returns:
+            Pitch-shifted audio signal
+        """
+        if n_steps == 0:
+            return y
+        return librosa.effects.pitch_shift(y, sr=sr, n_steps=n_steps)
+
     @staticmethod
     def merge_back_to_parent(
         parent_track_audio: np.ndarray,