# 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) ```