fix&feat: hiển thị tools chỉnh sửa audioclip

14_FIX_SUBTAB.md

@@ -0,0 +1,283 @@
+# Technical Specification: Advanced Editing Toolset & Graph-Based Continuous Waveform Painting on Sub-Tab
+
+This document defines the interactive layout design, the configuration of the toolbar button arrays, and the signal processing routines for compiling a Graph-based Continuous Waveform graph optimized for the microscopic viewports inside the isolated temporary document workspace (Sub-tab), referencing the structural paradigms of `image_5ec2e5.png` and `image_5ec363.png`.
+
+---
+
+## 1. Target Selection Scope
+
+The toolset within the Sub-tab environment supports two target operational boundaries:
+
+* **Global Clip:** When no specific timeline selection highlighted mask is present, all active DSP effects apply uniformly across the entire length of the extracted Audio Clip.
+* **Selected Range:** When an explicit timeline segment $[T_{\text{start}}, T_{\text{end}}]$ is highlighted by the user, DSP routines calculate changes exclusively inside those boundaries. Splice junctions automatically compute crossfades to mitigate transient click/pop anomalies.
+
+---
+
+## 2. Ruler-Based Tools
+
+These utilities display as intuitive, linear slider scales (Sliders/Rulers) embedded in the top toolbar row:
+
+```text
+[ Normalize: |======o======| 0 dB ]  [ Gain: |====o====| +3 dB ]  [ Pitch: |==o==| -2 Semi ]
+
+```
+
+### 2.1. Peak Normalization
+
+* **UI Layout:** A slide scale control allowing users to configure target amplitude thresholds variable from $-12\text{ dBFS}$ down to $0\text{ dBFS}$.
+* **DSP Math Algorithm:** Locate the maximum absolute peak amplitude value $A_{\text{max}}$ within the targeted area, then multiply all active samples by a static scalar gain multiplier $G$:
+
+$$G = \frac{10^{\frac{\text{Target\_dB}}{20}}}{A_{\text{max}}}$$
+
+
+
+### 2.2. Volume Up / Down (Quick Gain)
+
+* **UI Layout:** A linear sliding ruler modulating the overall absolute gain structure of the focused segment.
+* **Operational Range:** Adjustable from $-\infty\text{ dB}$ (complete mute attenuation) up to $+12\text{ dB}$ of linear amplification.
+
+### 2.3. Pitch Shifting
+
+* **UI Layout:** A calibrated slider modifying the project's fundamental frequencies discrete in semitones or cents.
+* **Operational Range:** Boundaries map from $-12\text{ semitones}$ (one octave down) to $+12\text{ semitones}$ (one octave up).
+* **DSP Engine Routine:** Employs a spectral Phase Vocoder to shift frequencies without affecting the physical, real-time duration layout of the segment.
+
+---
+
+## 3. Graph-Based Fades
+
+Fading curves overlay graphically directly onto the highlighted waveform canvas region, enabling precise boundary amplitude adjustments:
+
+```text
+          Linear Fade-In                         Exponential Fade-Out
+   +───────────────────────────+             +───────────────────────────+
+   |           /███████████████|             |███████████\               |
+   |         /  ███████████████|             |███████████  \             |
+   |       /    ███████████████|             |███████████    \___        |
+   |     /      ███████████████|             |███████████         \______|
+   +───────────────────────────+             +───────────────────────────+
+   |<──────── Fade-In ────────>|             |<─────── Fade-Out ────────>|
+
+```
+
+* **Fade-In:** Multiplies an ascending amplitude ramp from $0.0$ to $1.0$ at the starting index profile of the selection region. Users can toggle seamlessly between **Linear** or **Exponential** curves to achieve a smoother, more psychoacoustically natural volume build-up.
+* **Fade-Out:** Multiplies a descending amplitude decay ramp from $1.0$ down to $0.0$ at the trailing boundary edge of the selection range.
+
+---
+
+## 4. Ruler Percentage Stretch Tool
+
+A dedicated percentage metric scale control (`Ruler %`) sitting on the control toolbar dictates time-stretching and playback velocity parameters:
+
+```text
+[ Speed Stretch %: |========o========| 100% (Native) ] -> Range: 50% - 200%
+
+```
+
+* **Interaction Mapping:** Users drag the percentage slider node or hold down the `Alt` key and drag the rightmost boundary edge of the clip along the horizontal axis to change this scale metric.
+* **Sync Formula:** Let $D$ map to the unscaled native duration value, and $D'$ map to the target modified duration footprint. The resulting structural playback speed ratio percentage ($S$) is given by:
+
+$$S = \frac{D}{D'} \times 100\%$$
+
+
+
+---
+
+## 5. Continuous Graph-Based Waveform Painting & Microscopic Viewports
+
+The waveform graph inside the Sub-tab is compiled as a unified, continuous line vector (Continuous Line Graph) that flows seamlessly along the timeline axis, mapping the literal physical phase displacements of the underlying audio signal.
+
+### 5.1. Logarithmic Amplitude Axis Grid Layout
+
+Following the professional paradigm established in `image_5ec2e5.png`, the waveform painting canvas is divided by a symmetrical layout grid reflecting both positive and negative polarity limits of the central horizontal axis:
+
+```text
+  +6.0 dB ───────────────────────────────────────────────────────────────────
+           ~ ~ ~ ~ ~ ~ ~ ~ (Sub-division Grid Line) ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
+  -6.0 dB ───────────────────────────────────────────────────────────────────
+           \             /             \             /             \
+  -Inf dB  ─○───────────/───────────────○───────────/───────────────○───────── (Zero-Line Axis)
+             \         /                 \         /                 \
+  -6.0 dB ───────────────────────────────────────────────────────────────────
+  +6.0 dB ───────────────────────────────────────────────────────────────────
+
+```
+
+* **Visual Bounding Thresholds:**
+* **Central Zero Axis (-Inf. dB):** Maps the absolute baseline $0\text{V}$ electrical reference (complete absence of audio signal / absolute silence).
+* **Symmetrical Decibel Grids:** Project accurate scale metrics tracking normalized peak levels (the inner $-6.0\text{ dB}$ sub-grid marks a $50.1\%$ amplitude ceiling, while the outermost physical frame boundary aligns to $+6.0\text{ dB}$ or $0\text{ dBFS}$).
+
+
+
+### 5.2. Standard Workspace View vs. Ultra Zoom Viewport Scaling
+
+The drawing engine dynamically hot-swaps its rendering calculations (Rendering Routine) depending on the active pixel compression metric $Z$ (pixels/second):
+
+* **Standard View Mode ($Z < 500\text{ pixels/second}$):** The system deploys a structural peak compression layout algorithm (**Peak Waveform**—as referenced in `image_5ec2e5.png`). It connects the maximum absolute upper peak bounding indices (Max) with the lower minimum value ranges (Min) passing through a common pixel column into a unified vector line, generating an organic, aliases-free continuous waveform silhouette.
+* **Micro Viewport Zoom-In ($Z \ge 500\text{ pixels/second}$—as referenced in `image_5ec363.png`):** Once viewport stretching scales past this threshold, the framework transitions into a **Single Continuous Sine Polyline** loop. Chronologically sequential acoustic sample addresses ($x[i]$, $x[i+1]$) map as discrete vector coordinate indices bound together by thin lines (using sharp smooth polyline vectors or linear/cubic spline interpolation loops), charting pristine, individual sinusoidal phases explicitly.
+
+### 5.3. Zero-Crossing Alignment within Ultra Zoom Viewports
+
+When performing rapid cursor tracking edits (Scrub/Drag Selection), the alignment routine locks the selection boundary marker coordinates onto the nearest baseline sample offset exhibiting a complete algebraic phase conversion (sign inversion):
+
+
+$$x[i] \cdot x[i+1] \le 0$$
+
+---
+
+## 6. Top Duration Timeline
+
+Directly above the isolated sub-tab waveform canvas lane, a dedicated horizontal measuring ruler tracks clip timing data:
+
+```text
+   | 0:00.000    | 0:01.000    | 0:02.000    | 0:03.000    | 0:04.000 (Duration: 4.152s)
+   +───────────────────────────────────────────────────────────────────────────────────────+
+   | [==================== VÙNG QUÉT CHỌN (RANGE SELECTION) ====================]          |
+   +───────────────────────────────────────────────────────────────────────────────────────+
+
+```
+
+* **Total Duration Monitoring:** Renders the absolute, precise time extent of the isolated audio block in the right-hand corner of the timeline ruler layout (e.g., `Duration: 12.450s`).
+* **Duration Selection Drag:** Left-clicking and dragging horizontally inside this top duration bar defines a highlighted selection overlay window. This range indicator automatically projects down into the waveform lane underneath.
+
+---
+
+## 7. Bottom Transport Panel & Master Tools
+
+A comprehensive control framework containing expanded navigation buttons and deep session processing controls anchors the bottom row of the sub-tab environment, matching the layout structure in `image_5ec2e5.png`:
+
+```text
++─────────────────────────────────────────────────────────────────────────────────────────────+
+|  [● Rec]  [◀◀ Back]  [▶ Play]  [|| Pause]  [■ Stop]  |  Rate: |====o====| 0.00  |  Loop: [X]  |
+|---------------------------------------------------------------------------------------------|
+|  [Volume Pencil Tool]  [AI Analysis Tool]  | Active Asset: linh_ngua_powerup.wav            |
++─────────────────────────────────────────────────────────────────────────────────────────────+
+
+```
+
+### 7.1. Functional Mapping Matrix:
+
+* **Record (● Red Indicator):** Drives live microphone capture sequences targeted straight into the isolated sub-tab data matrix.
+* **Back (◀◀ Rewind):** Resets the timeline playhead position index back to the absolute starting point ($t = 0.0\text{ s}$).
+* **Play / Pause / Stop:** Coordinates low-latency runtime audio execution tracking locked onto the sub-tab's RAM cache blocks.
+* **Rate Slider:** Adjusts the global monitoring playback pitch speed metrics in real time without overwriting source asset length (calibrated step ranges variable from `-1.00` scaling up to `+1.00`).
+* **Loop Toggle:** Toggles continuous cycle loops over the highlighted section or the whole clip.
+* **Volume Pencil Tool:** Engages the drawing framework to map point nodes for automated amplitude envelopes.
+* **AI Analysis Tool:** Instructs the dockerized engine to evaluate rhythmic transient markers and pitch tracking grids.
+
+---
+
+## 8. Volume Automation Envelope (Pen Tool)
+
+This advanced timeline automation layer allows audio designers to draw custom gain curves over the background waveform graphics.
+
+```text
+                  VOLUME AUTOMATION ENVELOPE (PEN TOOL)
+   +3 dB ──────────────────────────────────────────────────────────────
+         \      Node 1                                  Node 3
+          \      ○                                       ○
+   0 dB ───\────/─\─────────────────────────────────────/─\─────────── (0 dB Unity Gain Axis)
+            \  /   \                                   /   \
+             \/     \                                 /     \
+              ○      \_______________________________/       \________
+            Node 2                                            Node 4
+  -30 dB ──────────────────────────────────────────────────────────────
+   |<─────────────────── Horizontal Axis (Time) ─────────────────────>|
+
+```
+
+### 8.1. Pen Tool Interaction Mechanics
+
+* **Activation:** Clicking the designated Pencil Tool icon in the control panel modifies the pointer device presentation into a pencil graphic.
+* **Envelope Initialization:** Activating the Pen Tool generates a solid horizontal neon green line representing $0\text{ dB}$ (Unity Gain) across the track workspace, acting as the baseline master axis.
+* **Drawing Automation Curves:**
+* Left-clicking anywhere along this line creates an adjustable anchor point (**Control Node**).
+* Dragging an initialized control node upward increases signal amplitude (up to a maximal ceiling boundary of $+3\text{ dB}$).
+* Dragging a control node downward reduces signal amplitude (down to a lower attenuation floor of $-30\text{ dB}$).
+* The graphics framework automatically updates straight vector paths between sequential nodes utilizing simple linear interpolation.
+
+
+
+### 8.2. DSP Volume Envelope Math
+
+Given two chronologically adjacent drawn points $P_1(t_1, V_1)$ and $P_2(t_2, V_2)$, the targeted instantaneous decibel gain variable $V_{\text{dB}}(t)$ at an arbitrary time index $t$ ($t_1 \le t \le t_2$) matches the following linear equation:
+
+
+$$V_{\text{dB}}(t) = V_1 + (t - t_1) \cdot \frac{V_2 - V_1}{t_2 - t_1}$$
+
+This decibel value must be translated into a standard linear gain scalar coefficient $G_{\text{linear}}(t)$ to multiply it into the core audio sample stream values:
+
+
+$$G_{\text{linear}}(t) = 10^{\frac{\text{V}_{\text{dB}}(t)}{20}}$$
+
+$$x_{\text{automation}}[n] = x[n] \cdot G_{\text{linear}}\left( \frac{n}{\text{Sample Rate}} \right)$$
+
+---
+
+## 9. Porting Guidelines for Python Desktop Layouts (PyQt6 QPainter Context)
+
+When translating the polyline vector engine and the symmetrical decibel gridding lines into a containerized desktop application using the native `QPainter` canvas inside PyQt6, leveraging a structured `QPainterPath` prevents rendering lag when mapping high-density signal segments:
+
+```python
+# [PYTHON PORTING BLUEPRINT] - Continuous Polyline Waveform Rendering via QPainterPath
+from PyQt6.QtGui import QPainter, QPainterPath, QPen, QColor
+from PyQt6.QtCore import QPointF, Qt
+import numpy as np
+
+def paint_continuous_waveform_path(painter: QPainter, rect_width: int, rect_height: int, y: np.ndarray, zoom_level: float):
+    """
+    Renders a unified continuous single polyline path tracing absolute physical signal transitions.
+    y: A 1D NumPy float32 array tracking raw sample amplitudes bounded within [-1.0, 1.0].
+    zoom_level: The scale allocation mapping physical drawing pixels per second of audio data.
+    """
+    if len(y) == 0:
+        return
+        
+    painter.setRenderHint(QPainter.RenderHint.Antialiasing, True)
+    mid_y = rect_height / 2.0
+    
+    # 1. Compile background Decibel reference grids (-6.0 dB, -Inf. dB, -6.0 dB)
+    grid_pen = QPen(QColor(45, 45, 45), 1, Qt.PenStyle.DashLine)
+    painter.setPen(grid_pen)
+    
+    # A threshold of -6.0 dB maps approximately to an absolute scalar amplitude index of 0.501
+    y_6db_top = mid_y - (0.501 * (rect_height * 0.42))
+    y_6db_bottom = mid_y + (0.501 * (rect_height * 0.42))
+    
+    painter.drawLine(0, int(y_6db_top), rect_width, int(y_6db_top))
+    painter.drawLine(0, int(y_6db_bottom), rect_width, int(y_6db_bottom))
+    
+    # Paint the absolute Zero-Line horizontal center axis (-Inf. dB)
+    center_pen = QPen(QColor(60, 60, 60), 1, Qt.PenStyle.SolidLine)
+    painter.setPen(center_pen)
+    painter.drawLine(0, int(mid_y), rect_width, int(mid_y))
+    
+    # 2. Initialize the Continuous Vector Polyline Route Layout Block
+    wave_path = QPainterPath()
+    wave_pen = QPen(QColor(100, 149, 237), 1.2, Qt.PenStyle.SolidLine) # Professional Cornflower Blue
+    painter.setPen(wave_pen)
+    
+    # Map raw buffer indexes into structural coordinate pixels
+    start_point_set = False
+    for x_pixel in range(rect_width):
+        # Translate current canvas pixel offset back to timeline seconds metrics
+        time_at_pixel = x_pixel / zoom_level
+        
+        # Calculate target array element offset
+        sample_index = int(time_at_pixel * 44100) # Assuming project sample rate baseline at 44.1kHz
+        if sample_index >= len(y):
+            break
+            
+        amplitude = y[sample_index]
+        y_pixel = mid_y + (amplitude * (rect_height * 0.42))
+        
+        if not start_point_set:
+            wave_path.moveTo(float(x_pixel), y_pixel)
+            start_point_set = True
+        else:
+            wave_path.lineTo(float(x_pixel), y_pixel)
+            
+    # Draw the continuous vector polyline overlay onto the viewport canvas
+    painter.drawPath(wave_path)
+
+```

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, 

app/templates/index.html

@@ -779,6 +779,41 @@
             );
         };
 
+        const SubTabToolbar = ({ st, activeTool, setActiveTool, handleSubTabNormalizeWithValue, handleSubTabGainWithValue, handleSubTabPitch, handleSubTabStretch, handleSubTabFade }) => (
+            <div className="daw-header flex h-16 items-center px-4 border-b daw-border gap-3 bg-zinc-800">
+                <div className="flex items-center space-x-1 border-r border-zinc-700 pr-3">
+                    <button className={`p-1.5 rounded ${activeTool === 'select' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('select')} title="Select"><i data-lucide="mouse-pointer" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'grab' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('grab')} title="Grab"><i data-lucide="hand" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'razor' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('razor')} title="Razor"><i data-lucide="scissors" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'pen' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('pen')} title="Pen Tool"><i data-lucide="pen-tool" className="w-4 h-4"></i></button>
+                </div>
+
+                <div className="flex items-center space-x-3 flex-1 overflow-x-auto no-scrollbar">
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Normalize:</span>
+                        <input type="range" min="-12" max="0" value={st.effects?.normalizeDb || 0} step="0.1" onChange={(e) => handleSubTabNormalizeWithValue(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Gain:</span>
+                        <input type="range" min="-40" max="24" value={st.effects?.gainDb || 0} step="0.1" onChange={(e) => handleSubTabGainWithValue(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Pitch:</span>
+                        <input type="range" min="-12" max="12" value={st.effects?.pitch || 0} step="0.1" onChange={(e) => handleSubTabPitch(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Stretch:</span>
+                        <input type="range" min="50" max="200" value={st.effects?.speedStretch || 100} step="1" onChange={(e) => handleSubTabStretch(st.id, parseInt(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                </div>
+
+                <div className="flex items-center space-x-1 pl-3 border-l border-zinc-700">
+                    <button onClick={() => handleSubTabFade(st.id, 'in')} className="px-2 py-1 text-[10px] rounded hover:bg-zinc-700">Fade In</button>
+                    <button onClick={() => handleSubTabFade(st.id, 'out')} className="px-2 py-1 text-[10px] rounded hover:bg-zinc-700">Fade Out</button>
+                </div>
+            </div>
+        );
+
         const App = () => {
             // ── State Definitions ──
              const [tracks, setTracks] = useState([
@@ -810,14 +845,6 @@
             snapValueRef.current = snapValue;
             const bpmRef = useRef(bpm);
             bpmRef.current = bpm;
-
-            useEffect(() => {
-                setTimeout(() => {
-                    if (window.lucide) {
-                        window.lucide.createIcons();
-                    }
-                }, 50);
-            }, [activeTool]);
             // BMP for Tempo Track - LOOP_EDITOR_2.md §6
             const [selectedTrackId, setSelectedTrackId] = useState('1');
             const [currentTime, setCurrentTime] = useState(0);
@@ -945,6 +972,15 @@
                 fadeOutMs: 0,
             });
 
+            // Lucide icons initialization
+            useEffect(() => {
+                setTimeout(() => {
+                    if (window.lucide) {
+                        window.lucide.createIcons();
+                    }
+                }, 50);
+            }, [activeTool, activeTab]);
+
              const timelineWrapperRef = useRef(null);
              const tcpContainerRef = useRef(null);
 
@@ -1380,7 +1416,7 @@
                     startTime: selLeft,
                     endTime: selRight,
                     buffer: subBuffer,
-                    effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0 },
+                    effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0, normalizeDb: 0, pitch: 0, speedStretch: 100 },
                     currentTime: 0,
                     selectionStart: null,
                     selectionEnd: null,
@@ -1421,7 +1457,7 @@
                       startTime: clip.startTime,
                       endTime: clip.startTime + clip.buffer.duration,
                       buffer: subBuffer,
-                      effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0 },
+                      effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0, normalizeDb: 0, pitch: 0, speedStretch: 100 },
                       currentTime: 0,
                       selectionStart: null,
                       selectionEnd: null,
@@ -1466,14 +1502,58 @@
                      const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeInMs / 1000 * sr));
                      for (let i = 0; i < fadeSamples; i++) edData[i] = edData[i] * (i / fadeSamples);
                  }
-                 // Fade out
+// Fade out
-                 if (fx.fadeOutMs > 0) {
+                  if (fx.fadeOutMs > 0) {
-                     const sr = edBuffer.sampleRate;
+                      const sr = edBuffer.sampleRate;
-                     const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeOutMs / 1000 * sr));
+                      const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeOutMs / 1000 * sr));
-                     for (let i = edData.length - fadeSamples; i < edData.length; i++) {
+                      for (let i = edData.length - fadeSamples; i < edData.length; i++) {
-                         edData[i] = edData[i] * ((edData.length - 1 - i) / fadeSamples);
+                          edData[i] = edData[i] * ((edData.length - 1 - i) / fadeSamples);
-                     }
+                      }
-                 }
+                  }
+                  // Normalize (apply to selection or entire buffer)
+                  if (fx.normalizeDb !== 0) {
+                      const targetDb = fx.normalizeDb;
+                      let maxVal = 0;
+                      for (let i = 0; i < edData.length; i++) {
+                          const abs = Math.abs(edData[i]);
+                          if (abs > maxVal) maxVal = abs;
+                      }
+                      if (maxVal > 0) {
+                          const targetAmp = Math.pow(10, targetDb / 20);
+                          const scale = targetAmp / maxVal;
+                          for (let i = 0; i < edData.length; i++) {
+                              edData[i] = Math.max(-1, Math.min(1, edData[i] * scale));
+                          }
+                      }
+                  }
+                  // Pitch shift (simple resample)
+                  if (fx.pitch !== 0) {
+                      const ratio = Math.pow(2, fx.pitch / 12);
+                      const newLength = Math.round(edData.length / ratio);
+                      const newData = new Float32Array(newLength);
+                      for (let i = 0; i < newLength; i++) {
+                          const srcIdx = i * ratio;
+                          const idx0 = Math.floor(srcIdx);
+                          const idx1 = Math.min(idx0 + 1, edData.length - 1);
+                          const frac = srcIdx - idx0;
+                          newData[i] = edData[idx0] * (1 - frac) + edData[idx1] * frac;
+                      }
+                      edData.set(newData);
+                  }
+                  // Speed stretch
+                  if (fx.speedStretch !== 100) {
+                      const ratio = fx.speedStretch / 100;
+                      const newLength = Math.round(edData.length * ratio);
+                      const newData = new Float32Array(newLength);
+                      for (let i = 0; i < newLength; i++) {
+                          const srcIdx = i / ratio;
+                          const idx0 = Math.floor(srcIdx);
+                          const idx1 = Math.min(idx0 + 1, edData.length - 1);
+                          const frac = srcIdx - idx0;
+                          newData[i] = edData[idx0] * (1 - frac) + edData[idx1] * frac;
+                      }
+                      edData.set(newData);
+                  }
 
                  if (subTab.clipId) {
                      // Clip-based merge
@@ -1549,6 +1629,33 @@
                 setSubTabs(prev => prev.map(s => s.id === tabId ? { ...s, effects: { ...s.effects, ...effects } } : s));
             };
 
+            const handleSubTabNormalizeWithValue = (tabId, normalizeDb) => {
+                updateSubTabEffects(tabId, { normalizeDb });
+            };
+
+            const handleSubTabGainWithValue = (tabId, gainDb) => {
+                updateSubTabEffects(tabId, { gainDb });
+            };
+
+            const handleSubTabPitch = (tabId, pitch) => {
+                updateSubTabEffects(tabId, { pitch });
+            };
+
+            const handleSubTabStretch = (tabId, speedStretch) => {
+                updateSubTabEffects(tabId, { speedStretch });
+            };
+
+            const handleSubTabFadeState = (tabId, type) => {
+                const st = subTabs.find(s => s.id === tabId);
+                if (!st) return;
+                const fx = st.effects || {};
+                if (type === 'in') {
+                    updateSubTabEffects(tabId, { fadeInMs: (fx.fadeInMs || 0) + 10 });
+                } else if (type === 'out') {
+                    updateSubTabEffects(tabId, { fadeOutMs: (fx.fadeOutMs || 0) + 10 });
+                }
+            };
+
             // ── Context Menu Handlers ──
             const handleContextMenu = (e, trackId, clickTime) => {
                 e.preventDefault();
@@ -4318,6 +4425,16 @@
                                     </button>
                                 </div>
                                 <div className="flex-1 flex flex-col p-3 gap-3 overflow-y-auto">
+                                    <SubTabToolbar 
+                                        st={st} 
+                                        activeTool={activeTool} 
+                                        setActiveTool={setActiveTool}
+                                        handleSubTabNormalizeWithValue={handleSubTabNormalizeWithValue}
+                                        handleSubTabGainWithValue={handleSubTabGainWithValue}
+                                        handleSubTabPitch={handleSubTabPitch}
+                                        handleSubTabStretch={handleSubTabStretch}
+                                        handleSubTabFade={handleSubTabFadeState}
+                                    />
                                     <SubTabWaveform 
                                         buffer={st.buffer}
                                         subTabId={st.id}

index.html

@@ -779,6 +779,41 @@
             );
         };
 
+        const SubTabToolbar = ({ st, activeTool, setActiveTool, handleSubTabNormalizeWithValue, handleSubTabGainWithValue, handleSubTabPitch, handleSubTabStretch, handleSubTabFade }) => (
+            <div className="daw-header flex h-16 items-center px-4 border-b daw-border gap-3 bg-zinc-800">
+                <div className="flex items-center space-x-1 border-r border-zinc-700 pr-3">
+                    <button className={`p-1.5 rounded ${activeTool === 'select' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('select')} title="Select"><i data-lucide="mouse-pointer" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'grab' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('grab')} title="Grab"><i data-lucide="hand" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'razor' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('razor')} title="Razor"><i data-lucide="scissors" className="w-4 h-4"></i></button>
+                    <button className={`p-1.5 rounded ${activeTool === 'pen' ? 'bg-cyan-700' : 'bg-zinc-700'}`} onClick={() => setActiveTool('pen')} title="Pen Tool"><i data-lucide="pen-tool" className="w-4 h-4"></i></button>
+                </div>
+
+                <div className="flex items-center space-x-3 flex-1 overflow-x-auto no-scrollbar">
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Normalize:</span>
+                        <input type="range" min="-12" max="0" value={st.effects?.normalizeDb || 0} step="0.1" onChange={(e) => handleSubTabNormalizeWithValue(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Gain:</span>
+                        <input type="range" min="-40" max="24" value={st.effects?.gainDb || 0} step="0.1" onChange={(e) => handleSubTabGainWithValue(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Pitch:</span>
+                        <input type="range" min="-12" max="12" value={st.effects?.pitch || 0} step="0.1" onChange={(e) => handleSubTabPitch(st.id, parseFloat(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                    <div className="flex items-center gap-1">
+                        <span className="text-[10px] text-zinc-400">Stretch:</span>
+                        <input type="range" min="50" max="200" value={st.effects?.speedStretch || 100} step="1" onChange={(e) => handleSubTabStretch(st.id, parseInt(e.target.value))} className="w-20 h-1.5"/>
+                    </div>
+                </div>
+
+                <div className="flex items-center space-x-1 pl-3 border-l border-zinc-700">
+                    <button onClick={() => handleSubTabFade(st.id, 'in')} className="px-2 py-1 text-[10px] rounded hover:bg-zinc-700">Fade In</button>
+                    <button onClick={() => handleSubTabFade(st.id, 'out')} className="px-2 py-1 text-[10px] rounded hover:bg-zinc-700">Fade Out</button>
+                </div>
+            </div>
+        );
+
         const App = () => {
             // ── State Definitions ──
              const [tracks, setTracks] = useState([
@@ -810,14 +845,6 @@
             snapValueRef.current = snapValue;
             const bpmRef = useRef(bpm);
             bpmRef.current = bpm;
-
-            useEffect(() => {
-                setTimeout(() => {
-                    if (window.lucide) {
-                        window.lucide.createIcons();
-                    }
-                }, 50);
-            }, [activeTool]);
             // BMP for Tempo Track - LOOP_EDITOR_2.md §6
             const [selectedTrackId, setSelectedTrackId] = useState('1');
             const [currentTime, setCurrentTime] = useState(0);
@@ -945,6 +972,15 @@
                 fadeOutMs: 0,
             });
 
+            // Lucide icons initialization
+            useEffect(() => {
+                setTimeout(() => {
+                    if (window.lucide) {
+                        window.lucide.createIcons();
+                    }
+                }, 50);
+            }, [activeTool, activeTab]);
+
              const timelineWrapperRef = useRef(null);
              const tcpContainerRef = useRef(null);
 
@@ -1380,7 +1416,7 @@
                     startTime: selLeft,
                     endTime: selRight,
                     buffer: subBuffer,
-                    effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0 },
+                    effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0, normalizeDb: 0, pitch: 0, speedStretch: 100 },
                     currentTime: 0,
                     selectionStart: null,
                     selectionEnd: null,
@@ -1421,7 +1457,7 @@
                       startTime: clip.startTime,
                       endTime: clip.startTime + clip.buffer.duration,
                       buffer: subBuffer,
-                      effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0 },
+                      effects: { reverse: false, gainDb: 0, fadeInMs: 0, fadeOutMs: 0, normalizeDb: 0, pitch: 0, speedStretch: 100 },
                       currentTime: 0,
                       selectionStart: null,
                       selectionEnd: null,
@@ -1466,14 +1502,58 @@
                      const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeInMs / 1000 * sr));
                      for (let i = 0; i < fadeSamples; i++) edData[i] = edData[i] * (i / fadeSamples);
                  }
-                 // Fade out
+// Fade out
-                 if (fx.fadeOutMs > 0) {
+                  if (fx.fadeOutMs > 0) {
-                     const sr = edBuffer.sampleRate;
+                      const sr = edBuffer.sampleRate;
-                     const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeOutMs / 1000 * sr));
+                      const fadeSamples = Math.min(edData.length, Math.floor(fx.fadeOutMs / 1000 * sr));
-                     for (let i = edData.length - fadeSamples; i < edData.length; i++) {
+                      for (let i = edData.length - fadeSamples; i < edData.length; i++) {
-                         edData[i] = edData[i] * ((edData.length - 1 - i) / fadeSamples);
+                          edData[i] = edData[i] * ((edData.length - 1 - i) / fadeSamples);
-                     }
+                      }
-                 }
+                  }
+                  // Normalize (apply to selection or entire buffer)
+                  if (fx.normalizeDb !== 0) {
+                      const targetDb = fx.normalizeDb;
+                      let maxVal = 0;
+                      for (let i = 0; i < edData.length; i++) {
+                          const abs = Math.abs(edData[i]);
+                          if (abs > maxVal) maxVal = abs;
+                      }
+                      if (maxVal > 0) {
+                          const targetAmp = Math.pow(10, targetDb / 20);
+                          const scale = targetAmp / maxVal;
+                          for (let i = 0; i < edData.length; i++) {
+                              edData[i] = Math.max(-1, Math.min(1, edData[i] * scale));
+                          }
+                      }
+                  }
+                  // Pitch shift (simple resample)
+                  if (fx.pitch !== 0) {
+                      const ratio = Math.pow(2, fx.pitch / 12);
+                      const newLength = Math.round(edData.length / ratio);
+                      const newData = new Float32Array(newLength);
+                      for (let i = 0; i < newLength; i++) {
+                          const srcIdx = i * ratio;
+                          const idx0 = Math.floor(srcIdx);
+                          const idx1 = Math.min(idx0 + 1, edData.length - 1);
+                          const frac = srcIdx - idx0;
+                          newData[i] = edData[idx0] * (1 - frac) + edData[idx1] * frac;
+                      }
+                      edData.set(newData);
+                  }
+                  // Speed stretch
+                  if (fx.speedStretch !== 100) {
+                      const ratio = fx.speedStretch / 100;
+                      const newLength = Math.round(edData.length * ratio);
+                      const newData = new Float32Array(newLength);
+                      for (let i = 0; i < newLength; i++) {
+                          const srcIdx = i / ratio;
+                          const idx0 = Math.floor(srcIdx);
+                          const idx1 = Math.min(idx0 + 1, edData.length - 1);
+                          const frac = srcIdx - idx0;
+                          newData[i] = edData[idx0] * (1 - frac) + edData[idx1] * frac;
+                      }
+                      edData.set(newData);
+                  }
 
                  if (subTab.clipId) {
                      // Clip-based merge
@@ -1549,6 +1629,33 @@
                 setSubTabs(prev => prev.map(s => s.id === tabId ? { ...s, effects: { ...s.effects, ...effects } } : s));
             };
 
+            const handleSubTabNormalizeWithValue = (tabId, normalizeDb) => {
+                updateSubTabEffects(tabId, { normalizeDb });
+            };
+
+            const handleSubTabGainWithValue = (tabId, gainDb) => {
+                updateSubTabEffects(tabId, { gainDb });
+            };
+
+            const handleSubTabPitch = (tabId, pitch) => {
+                updateSubTabEffects(tabId, { pitch });
+            };
+
+            const handleSubTabStretch = (tabId, speedStretch) => {
+                updateSubTabEffects(tabId, { speedStretch });
+            };
+
+            const handleSubTabFadeState = (tabId, type) => {
+                const st = subTabs.find(s => s.id === tabId);
+                if (!st) return;
+                const fx = st.effects || {};
+                if (type === 'in') {
+                    updateSubTabEffects(tabId, { fadeInMs: (fx.fadeInMs || 0) + 10 });
+                } else if (type === 'out') {
+                    updateSubTabEffects(tabId, { fadeOutMs: (fx.fadeOutMs || 0) + 10 });
+                }
+            };
+
             // ── Context Menu Handlers ──
             const handleContextMenu = (e, trackId, clickTime) => {
                 e.preventDefault();
@@ -4318,6 +4425,16 @@
                                     </button>
                                 </div>
                                 <div className="flex-1 flex flex-col p-3 gap-3 overflow-y-auto">
+                                    <SubTabToolbar 
+                                        st={st} 
+                                        activeTool={activeTool} 
+                                        setActiveTool={setActiveTool}
+                                        handleSubTabNormalizeWithValue={handleSubTabNormalizeWithValue}
+                                        handleSubTabGainWithValue={handleSubTabGainWithValue}
+                                        handleSubTabPitch={handleSubTabPitch}
+                                        handleSubTabStretch={handleSubTabStretch}
+                                        handleSubTabFade={handleSubTabFadeState}
+                                    />
                                     <SubTabWaveform 
                                         buffer={st.buffer}
                                         subTabId={st.id}

tests/test_sub_tab_dsp.py

@@ -42,3 +42,39 @@ def test_merge_back_to_parent():
     assert np.allclose(res[:900], 1.0)
     # Inside the edited range should be zero (except crossfades)
     assert np.allclose(res[1100:2900], 0.0)
+
+def test_apply_volume_automation_envelope():
+    sr = 44100
+    duration = 2.0
+    y = np.ones(int(sr * duration), dtype=np.float32) * 0.5  # Constant signal at -6dB
+
+    # Simple fade in from -inf to 0dB over 1 second
+    nodes = [
+        {"time": 0.0, "db": -60.0}, # Effectively -inf
+        {"time": 1.0, "db": 0.0},
+        {"time": 2.0, "db": 0.0},
+    ]
+    
+    y_automated = SubTabDSPEngine.apply_volume_automation_envelope(y, sr, nodes)
+
+    y_automated = SubTabDSPEngine.apply_volume_automation_envelope(y, sr, nodes)
+
+    # Check start: should be 0.5 * 10**(-30/20) due to clipping
+    expected_start_val = 0.5 * (10**(-30/20.0))
+    assert np.isclose(y_automated[0], expected_start_val, atol=1e-5)
+    
+    # Check at 0.5 seconds: interpolated to -15dB (halfway between -30dB and 0dB)
+    # y * (10 ** (-15 / 20))
+    expected_mid_val = 0.5 * (10**(-15/20.0))
+    assert np.isclose(y_automated[int(0.5 * sr)], expected_mid_val, atol=1e-5)
+
+    # Check at 1.0 seconds: should be 0.5 * (10**(0/20)) = 0.5
+    assert np.isclose(y_automated[int(1.0 * sr)], 0.5, atol=1e-5)
+
+    # Check at end: should be 0.5
+    assert np.isclose(y_automated[-1], 0.5, atol=1e-5)
+
+    # Test with empty nodes
+    y_no_nodes = SubTabDSPEngine.apply_volume_automation_envelope(y, sr, [])
+    assert np.array_equal(y_no_nodes, y)
+