feat(synth): Enhance 8-bit synthesizer and expand presets

This major update significantly enhances the capabilities of the 8-bit style synthesizer and expands the preset library with a wide range of iconic and experimental sounds.

**Synthesizer Engine Enhancements:**

The `synthesize_8bit_style` function has been upgraded with four new parameters to allow for more complex and authentic sound design, moving beyond basic subtractive synthesis:

- **Noise Channel (`noise_level`):** Adds a layer of white noise, essential for creating percussive sounds, atmospheric textures, and adding grit.
- **Waveform Distortion (`distortion_level`):** Introduces a wave-shaping algorithm to simulate the hardware clipping and saturation found in vintage consoles, enabling harsher and more aggressive tones.
- **Frequency Modulation (`fm_modulation_depth`, `fm_modulation_rate`):** Implements a basic FM synthesis capability, allowing for the creation of complex, metallic, and bell-like timbres reminiscent of sound chips like the Yamaha YM2612.
___

The `S8BIT_PRESETS` dictionary has been massively expanded and reorganized to showcase the new engine's capabilities. This includes:

1. **Rhythm Pop Lead:** A clean, round square wave perfect for the snappy, catchy feel of rhythm games.
2. **Arcade Brawler Lead:** A gritty sawtooth lead with a hard attack, capturing the high-energy feel of classic fighting games.
3. **Mega Man (Rockman):** A thin, sharp square wave lead with fast vibrato, iconic for its driving, heroic melodies.
4. **Kirby's Bubbly Melody:** A soft, round square wave with a bouncy vibrato, creating a cheerful and adorable sound.
5. **Mario (Super Mario Bros):** A bright square wave with a per-note vibrato, producing the classic bouncy platformer sound.
6. **Mecha & Tactics Brass:** A powerful, sustained sawtooth emulating the bold, heroic synth-brass of strategy and mecha anime themes.
7. **Mystic Mana Pad:** A warm, ethereal square wave pad with slow vibrato, capturing a feeling of fantasy and wonder.
8. **Dragon Quest (Orchestral Feel):** A pure triangle wave with a long decay, mimicking the grand, orchestral feel of a classical flute or string section.
9. **ONI V (Wafu Mystic):** A solemn triangle wave with a slow, expressive vibrato, evoking the mysterious atmosphere of Japanese folklore.
10. **Zelda (NES):** The classic pure triangle wave lead, perfect for heroic and adventurous overworld themes.
11. **Falcom Ys (Rock Lead):** A powerful sawtooth with slight distortion, emulating the driving rock organ and guitar leads of action JRPGs.
12. **Final Fantasy (Arpeggio):** A perfect, clean square wave with zero vibrato, creating the iconic, crystal-clear arpeggio sound.
13. **Castlevania (Akumajō Dracula):** A sharp square wave with dramatic vibrato, ideal for fast, gothic, and baroque-inspired melodies.
14. **Pokémon (Game Boy Classics):** A full, friendly square wave sound, capturing the cheerful and adventurous spirit of early handheld RPGs.
15. **Commodore 64 (SID Feel):** (Impression) Uses high-speed, shallow vibrato to mimic the characteristic "buzzy" texture of the SID chip's PWM.
16. **Megadrive/Genesis (FM Grit):** (Impression) Uses FM, distortion, and noise to capture the gritty, metallic, and aggressive tone of the YM2612 chip.
17. **PC-98 (Touhou Feel):** (Impression) A very sharp square wave with fast FM, emulating the bright, high-energy leads of Japanese PC games.
18. **Roland SC-88 (GM Vibe):** (Impression) A clean, stable triangle wave with no effects, mimicking the polished, sample-based sounds of General MIDI.
19. **Sci-Fi Energy Field:** (SFX) High-speed vibrato and noise create a constant, shimmering hum suitable for energy shields or force fields.
20. **Industrial Alarm:** (SFX) Extreme vibrato rate on a sawtooth wave produces a harsh, metallic, dissonant alarm sound.
21. **Laser Charge-Up:** (SFX) Extreme vibrato depth creates a dramatic, rising pitch effect, perfect for sci-fi weapon sounds.
22. **Unstable Machine Core:** (SFX) Maximum depth and distortion create a chaotic, atonal noise, simulating a machine on the verge of exploding.
23. **Hardcore Gabber Kick:** (Experimental) Maximum bass boost and distortion create an overwhelmingly powerful, clipped kick drum sound.
24. **Generic Chiptune Loop:** A well-balanced, pleasant square wave lead that serves as a great starting point for custom sounds.
25. **Dark/Boss Atmosphere:** An aggressive sawtooth with heavy bass and distortion, perfect for tense or menacing background music.

app.py

@@ -164,7 +164,10 @@ def prepare_soundfonts():
 # =================================================================================================
 # === 8-bit Style Synthesizer (Stereo Enabled) ===
 # =================================================================================================
-def synthesize_8bit_style(midi_data, waveform_type, envelope_type, decay_time_s, pulse_width, vibrato_rate, vibrato_depth, bass_boost_level, fs=44100):
+def synthesize_8bit_style(midi_data, waveform_type, envelope_type, decay_time_s, pulse_width,
+                           vibrato_rate, vibrato_depth, bass_boost_level, fs=44100,
+                           smooth_notes=False, continuous_vibrato=False, noise_level=0.0,
+                           distortion_level=0.0, fm_modulation_depth=0.0, fm_modulation_rate=0.0):
     """
     Synthesizes an 8-bit style audio waveform from a PrettyMIDI object.
     This function generates waveforms manually instead of using a synthesizer like FluidSynth.
@@ -175,9 +178,14 @@ def synthesize_8bit_style(midi_data, waveform_type, envelope_type, decay_time_s,
     total_duration = midi_data.get_end_time()
     # Initialize a stereo waveform buffer (2 channels: Left, Right)
     waveform = np.zeros((2, int(total_duration * fs) + fs))
-    
+
     num_instruments = len(midi_data.instruments)
 
+    # Phase tracking: main oscillator phase for each instrument
+    osc_phase = {}
+    # Vibrato phase tracking
+    vibrato_phase = 0.0
+
     for i, instrument in enumerate(midi_data.instruments):
         # --- Panning Logic ---
         # Default to center-panned mono
@@ -188,57 +196,103 @@ def synthesize_8bit_style(midi_data, waveform_type, envelope_type, decay_time_s,
             elif i == 1:  # Second instrument panned right
                 pan_l, pan_r = 0.0, 1.0
         elif num_instruments > 2:
-            if i == 0: pan_l, pan_r = 1.0, 0.0 # Left
-            elif i == 1: pan_l, pan_r = 0.0, 1.0 # Right
+            if i == 0:  # Left
+                pan_l, pan_r = 1.0, 0.0
+            elif i == 1: # Right
+                pan_l, pan_r = 0.0, 1.0
             # Other instruments remain centered
 
+        osc_phase[i] = 0.0  # Independent phase tracking for each instrument
+
         for note in instrument.notes:
             freq = pretty_midi.note_number_to_hz(note.pitch)
             note_duration = note.end - note.start
             num_samples = int(note_duration * fs)
-            if num_samples == 0:
+            if num_samples <= 0:
                 continue
 
-            t = np.linspace(0., note_duration, num_samples, endpoint=False)
-            
+            t = np.arange(num_samples) / fs
+
             # --- Vibrato LFO ---
-            vibrato_lfo = vibrato_depth * np.sin(2 * np.pi * vibrato_rate * t)
+            if continuous_vibrato:
+                # Use accumulated phase to avoid vibrato reset per note
+                vib_phase_inc = 2 * np.pi * vibrato_rate / fs
+                vib_phase_array = vibrato_phase + np.arange(num_samples) * vib_phase_inc
+                vibrato_phase = (vib_phase_array[-1] + vib_phase_inc) % (2 * np.pi)
+                vibrato_lfo = vibrato_depth * np.sin(vib_phase_array)
+            else:
+                vibrato_lfo = vibrato_depth * np.sin(2 * np.pi * vibrato_rate * t)
+                
+            # --- Waveform Generation (Main Oscillator with phase continuity) ---
+            phase_inc = 2 * np.pi * (freq + vibrato_lfo) / fs
+            phase = osc_phase[i] + np.cumsum(phase_inc)
+            osc_phase[i] = phase[-1] % (2 * np.pi)  # Store last phase
 
-            # --- Waveform Generation (Main Oscillator) ---
             if waveform_type == 'Square':
-                note_waveform = signal.square(2 * np.pi * (freq + vibrato_lfo) * t, duty=pulse_width)
+                note_waveform = signal.square(phase, duty=pulse_width)
             elif waveform_type == 'Sawtooth':
-                note_waveform = signal.sawtooth(2 * np.pi * (freq + vibrato_lfo) * t)
+                note_waveform = signal.sawtooth(phase)
             elif waveform_type == 'Triangle':
-                note_waveform = signal.sawtooth(2 * np.pi * (freq + vibrato_lfo) * t, width=0.5)
-
+                note_waveform = signal.sawtooth(phase, width=0.5)
+                
             # --- Bass Boost (Sub-Octave Oscillator) ---
             if bass_boost_level > 0:
                 bass_freq = freq / 2.0
                 # Only add bass if the frequency is reasonably audible
                 if bass_freq > 20:
                     # Bass uses a simple square wave, no vibrato, for stability
-                    bass_sub_waveform = signal.square(2 * np.pi * bass_freq * t, duty=0.5)
+                    bass_phase_inc = 2 * np.pi * bass_freq / fs
+                    bass_phase = np.cumsum(np.full(num_samples, bass_phase_inc))
+                    bass_sub_waveform = signal.square(bass_phase, duty=0.5)
                     # Mix the main and bass waveforms.
                     # As bass level increases, slightly decrease main waveform volume to prevent clipping.
                     main_level = 1.0 - (0.5 * bass_boost_level)
                     note_waveform = (note_waveform * main_level) + (bass_sub_waveform * bass_boost_level)
 
+            # --- Noise Channel Simulation (White Noise) ---
+            if noise_level > 0:
+                noise_waveform = np.random.uniform(-1, 1, num_samples)
+                note_waveform += noise_waveform * noise_level
+
+            # --- Distortion (Wave Shaping) ---
+            if distortion_level > 0:
+                note_waveform = np.sign(note_waveform) * np.abs(note_waveform) ** (1.0 - distortion_level)
+
+            # --- Frequency Modulation (FM) ---
+            if fm_modulation_depth > 0:
+                modulated_freq = freq * (1 + fm_modulation_depth * np.sin(2 * np.pi * fm_modulation_rate * t))
+                phase_inc = 2 * np.pi * modulated_freq / fs
+                phase = osc_phase[i] + np.cumsum(phase_inc)
+                osc_phase[i] = phase[-1] % (2 * np.pi)  # Store last phase
+                if waveform_type == 'Square':
+                    note_waveform = signal.square(phase, duty=pulse_width)
+                elif waveform_type == 'Sawtooth':
+                    note_waveform = signal.sawtooth(phase)
+                elif waveform_type == 'Triangle':
+                    note_waveform = signal.sawtooth(phase, width=0.5)
+
             # --- ADSR Envelope ---
             start_amp = note.velocity / 127.0
             envelope = np.zeros(num_samples)
-            
-            if envelope_type == 'Plucky (AD Envelope)' and num_samples > 0:
+
+            if envelope_type == 'Plucky (AD Envelope)':
                 attack_time_s = 0.005
                 attack_samples = min(int(attack_time_s * fs), num_samples)
                 decay_samples = min(int(decay_time_s * fs), num_samples - attack_samples)
-                
+
                 envelope[:attack_samples] = np.linspace(0, start_amp, attack_samples)
                 if decay_samples > 0:
                     envelope[attack_samples:attack_samples+decay_samples] = np.linspace(start_amp, 0, decay_samples)
-            elif envelope_type == 'Sustained (Full Decay)' and num_samples > 0:
+            elif envelope_type == 'Sustained (Full Decay)':
                 envelope = np.linspace(start_amp, 0, num_samples)
 
+            if smooth_notes:
+                # Add short release
+                release_samples = min(int(0.005 * fs), num_samples)
+                envelope[-release_samples:] *= np.linspace(1, 0, release_samples)
+                # Small crossfade (to avoid clicks)
+                envelope[:min(10, num_samples)] *= np.linspace(0.5, 1, min(10, num_samples))
+
             # Apply envelope to the (potentially combined) waveform
             note_waveform *= envelope
 
@@ -247,11 +301,11 @@ def synthesize_8bit_style(midi_data, waveform_type, envelope_type, decay_time_s,
             if end_sample > waveform.shape[1]:
                 end_sample = waveform.shape[1]
                 note_waveform = note_waveform[:end_sample-start_sample]
-            
+
             # Add the mono note waveform to the stereo buffer with panning
             waveform[0, start_sample:end_sample] += note_waveform * pan_l
             waveform[1, start_sample:end_sample] += note_waveform * pan_r
-            
+
     return waveform # Returns a (2, N) numpy array
 
 
@@ -518,7 +572,8 @@ def Render_MIDI(input_midi_path,
                 # --- 8-bit synth params ---
                 s8bit_waveform_type, s8bit_envelope_type, s8bit_decay_time_s, 
                 s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth,
-                s8bit_bass_boost_level
+                s8bit_bass_boost_level, s8bit_smooth_notes, s8bit_continuous_vibrato,
+                s8bit_noise_level, s8bit_distortion_level, s8bit_fm_modulation_depth, s8bit_fm_modulation_rate
                 ):
     """
     Processes and renders a MIDI file according to user-defined settings.
@@ -737,12 +792,19 @@ def Render_MIDI(input_midi_path,
             # Load the MIDI file with pretty_midi for manual synthesis
             midi_data_for_synth = pretty_midi.PrettyMIDI(midi_to_render_path)
             # Synthesize the waveform
+            # --- Passing new FX parameters to the synthesis function ---
             audio = synthesize_8bit_style(
                 midi_data_for_synth,
                 s8bit_waveform_type, s8bit_envelope_type, s8bit_decay_time_s, 
                 s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth,
                 s8bit_bass_boost_level,
-                fs=srate
+                fs=srate,
+                smooth_notes=s8bit_smooth_notes,
+                continuous_vibrato=s8bit_continuous_vibrato,
+                noise_level=s8bit_noise_level,
+                distortion_level=s8bit_distortion_level,
+                fm_modulation_depth=s8bit_fm_modulation_depth,
+                fm_modulation_rate=s8bit_fm_modulation_rate
             )
             # Normalize and prepare for Gradio
             peak_val = np.max(np.abs(audio))
@@ -809,7 +871,8 @@ def process_and_render_file(input_file,
                             # --- 8-bit synth params ---
                             s8bit_waveform_type, s8bit_envelope_type, s8bit_decay_time_s, 
                             s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth,
-                            s8bit_bass_boost_level
+                            s8bit_bass_boost_level, s8bit_smooth_notes, s8bit_continuous_vibrato,
+                            s8bit_noise_level, s8bit_distortion_level, s8bit_fm_modulation_depth, s8bit_fm_modulation_rate
                            ):
     """
     Main function to handle file processing. It determines the file type and calls the
@@ -920,12 +983,16 @@ def process_and_render_file(input_file,
 
     # --- Step 2: Render the MIDI file with selected options ---
     print(f"Proceeding to render MIDI file: {os.path.basename(midi_path_for_rendering)}")
+    # --- Passing new FX parameters to the Render_MIDI function ---
     results = Render_MIDI(midi_path_for_rendering,
                           render_type, soundfont_bank, render_sample_rate,
                           render_with_sustains, merge_misaligned_notes, custom_render_patch, render_align,
                           render_transpose_value, render_transpose_to_C4, render_output_as_solo_piano, render_remove_drums,
                           s8bit_waveform_type, s8bit_envelope_type, s8bit_decay_time_s, 
-                          s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth, s8bit_bass_boost_level)
+                          s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth, s8bit_bass_boost_level,
+                          s8bit_smooth_notes, s8bit_continuous_vibrato,
+                          s8bit_noise_level, s8bit_distortion_level, s8bit_fm_modulation_depth, s8bit_fm_modulation_rate
+                          )
     
     print(f'Total processing time: {(reqtime.time() - start_time):.2f} sec')
     print('*' * 70)
@@ -948,6 +1015,42 @@ def update_ui_visibility(transcription_method, soundfont_choice):
         synth_8bit_settings: gr.update(visible=is_8bit),
     }
 
+# --- Function to apply 8-bit synthesizer presets ---
+def apply_8bit_preset(preset_name):
+    """
+    Takes the name of a preset and returns a dictionary of gr.update objects
+    to set the values of the 8-bit synthesizer's UI components.
+    """
+    # If the user selects "Custom" or the preset is not found, do not change the values.
+    if preset_name == "Custom" or preset_name not in S8BIT_PRESETS:
+        return {
+            s8bit_waveform_type: gr.update(),
+            s8bit_pulse_width: gr.update(),
+            s8bit_envelope_type: gr.update(),
+            s8bit_decay_time_s: gr.update(),
+            s8bit_vibrato_rate: gr.update(),
+            s8bit_vibrato_depth: gr.update(),
+            s8bit_smooth_notes: gr.update(),
+            s8bit_continuous_vibrato: gr.update(),
+            s8bit_bass_boost_level: gr.update()
+        }
+    
+    # Get the settings dictionary for the chosen preset.
+    settings = S8BIT_PRESETS[preset_name]
+    
+    # Return a dictionary that maps each UI component to a gr.update call with the new value.
+    return {
+        s8bit_waveform_type: gr.update(value=settings['waveform_type']),
+        s8bit_pulse_width: gr.update(value=settings['pulse_width']),
+        s8bit_envelope_type: gr.update(value=settings['envelope_type']),
+        s8bit_decay_time_s: gr.update(value=settings['decay_time_s']),
+        s8bit_vibrato_rate: gr.update(value=settings['vibrato_rate']),
+        s8bit_vibrato_depth: gr.update(value=settings['vibrato_depth']),
+        s8bit_smooth_notes: gr.update(value=settings['smooth_notes']),
+        s8bit_continuous_vibrato: gr.update(value=settings['continuous_vibrato']),
+        s8bit_bass_boost_level: gr.update(value=settings['bass_boost_level'])
+    }
+
 if __name__ == "__main__":
     # Initialize the app: download model (if needed) and apply patches
     # Set to False if you don't have 'requests' or 'tqdm' installed
@@ -962,6 +1065,144 @@ if __name__ == "__main__":
     if not soundfonts_dict:
         print("\nWARNING: No SoundFonts were found or could be downloaded.")
         print("Rendering with SoundFonts will fail. Only the 8-bit synthesizer will be available.")
+    
+    # --- Data structure for 8-bit synthesizer presets ---
+    # Comprehensive preset dictionary with new FX parameters for all presets
+    # Comprehensive preset dictionary including new JRPG and Handheld classics
+    # Note: Vibrato depth is mapped to a representative value on the 0-50 Hz slider.
+    S8BIT_PRESETS = {
+        # --- Rhythmic & Action ---
+        "Rhythm Pop Lead": {
+            # Description: A clean, round square wave perfect for the snappy, catchy feel of rhythm games.
+            'waveform_type': 'Square', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.18, 'vibrato_rate': 4.5, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.3, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Arcade Brawler Lead": {
+            # Description: A gritty sawtooth lead with a hard attack, capturing the high-energy feel of classic fighting games.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.15, 'vibrato_rate': 5.0, 'vibrato_depth': 6,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.4, 'noise_level': 0.05, 'distortion_level': 0.1, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Mega Man (Rockman)": {
+            # Description: A thin, sharp square wave lead with fast vibrato, iconic for its driving, heroic melodies.
+            'waveform_type': 'Square', 'pulse_width': 0.2, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.15, 'vibrato_rate': 6.0, 'vibrato_depth': 8,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.3, 'noise_level': 0.0, 'distortion_level': 0.05, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Kirby's Bubbly Melody": {
+            # Description: A soft, round square wave with a bouncy vibrato, creating a cheerful and adorable sound.
+            'waveform_type': 'Square', 'pulse_width': 0.4, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.2, 'vibrato_rate': 6.0, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': False, 'bass_boost_level': 0.1, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Mario (Super Mario Bros)": {
+            # Description: A bright square wave with a per-note vibrato, producing the classic bouncy platformer sound.
+            'waveform_type': 'Square', 'pulse_width': 0.3, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.25, 'vibrato_rate': 5.0, 'vibrato_depth': 5,
+            'smooth_notes': True, 'continuous_vibrato': False, 'bass_boost_level': 0.2, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        # --- Epic & Atmospheric ---
+        "Mecha & Tactics Brass": {
+            # Description: A powerful, sustained sawtooth emulating the bold, heroic synth-brass of strategy and mecha anime themes.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.4, 'vibrato_rate': 3.5, 'vibrato_depth': 5,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.5, 'noise_level': 0.1, 'distortion_level': 0.15, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Mystic Mana Pad": {
+            # Description: A warm, ethereal square wave pad with slow vibrato, capturing a feeling of fantasy and wonder.
+            'waveform_type': 'Square', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.5, 'vibrato_rate': 2.5, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.3, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Dragon Quest (Orchestral Feel)": {
+            # Description: A pure triangle wave with a long decay, mimicking the grand, orchestral feel of a classical flute or string section.
+            'waveform_type': 'Triangle', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.6, 'vibrato_rate': 3.0, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.3, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "ONI V (Wafu Mystic)": {
+            # Description: A solemn triangle wave with a slow, expressive vibrato, evoking the mysterious atmosphere of Japanese folklore.
+            'waveform_type': 'Triangle', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.4, 'vibrato_rate': 3.5, 'vibrato_depth': 3,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.4, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Zelda (NES)": {
+            # Description: The classic pure triangle wave lead, perfect for heroic and adventurous overworld themes.
+            'waveform_type': 'Triangle', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.3, 'vibrato_rate': 4.5, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.15, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        # --- JRPG & System Classics ---
+        "Falcom Ys (Rock Lead)": {
+            # Description: A powerful sawtooth with slight distortion, emulating the driving rock organ and guitar leads of action JRPGs.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.15, 'vibrato_rate': 5.5, 'vibrato_depth': 6,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.4, 'noise_level': 0.05, 'distortion_level': 0.15, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Final Fantasy (Arpeggio)": {
+            # Description: A perfect, clean square wave with zero vibrato, creating the iconic, crystal-clear arpeggio sound.
+            'waveform_type': 'Square', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.22, 'vibrato_rate': 5.0, 'vibrato_depth': 0,
+            'smooth_notes': True, 'continuous_vibrato': False, 'bass_boost_level': 0.2, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Castlevania (Akumajō Dracula)": {
+            # Description: A sharp square wave with dramatic vibrato, ideal for fast, gothic, and baroque-inspired melodies.
+            'waveform_type': 'Square', 'pulse_width': 0.25, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.18, 'vibrato_rate': 6.5, 'vibrato_depth': 6,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.35, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Pokémon (Game Boy Classics)": {
+            # Description: A full, friendly square wave sound, capturing the cheerful and adventurous spirit of early handheld RPGs.
+            'waveform_type': 'Square', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.22, 'vibrato_rate': 5.0, 'vibrato_depth': 5,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.25, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        # --- Advanced System Impressions ---
+        "Commodore 64 (SID Feel)": {
+            # Description: (Impression) Uses high-speed, shallow vibrato to mimic the characteristic "buzzy" texture of the SID chip's PWM.
+            'waveform_type': 'Square', 'pulse_width': 0.25, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.25, 'vibrato_rate': 8.0, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': False, 'bass_boost_level': 0.2, 'noise_level': 0.05, 'distortion_level': 0.1, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Megadrive/Genesis (FM Grit)": {
+            # Description: (Impression) Uses FM, distortion, and noise to capture the gritty, metallic, and aggressive tone of the YM2612 chip.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.18, 'vibrato_rate': 0.0, 'vibrato_depth': 0,
+            'smooth_notes': False, 'continuous_vibrato': True, 'bass_boost_level': 0.4, 'noise_level': 0.1, 'distortion_level': 0.2, 'fm_modulation_depth': 0.2, 'fm_modulation_rate': 150
+        },
+        "PC-98 (Touhou Feel)": {
+            # Description: (Impression) A very sharp square wave with fast FM, emulating the bright, high-energy leads of Japanese PC games.
+            'waveform_type': 'Square', 'pulse_width': 0.15, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.12, 'vibrato_rate': 7.5, 'vibrato_depth': 7,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.3, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.1, 'fm_modulation_rate': 200
+        },
+        "Roland SC-88 (GM Vibe)": {
+            # Description: (Impression) A clean, stable triangle wave with no effects, mimicking the polished, sample-based sounds of General MIDI.
+            'waveform_type': 'Triangle', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.35, 'vibrato_rate': 0, 'vibrato_depth': 0,
+            'smooth_notes': True, 'continuous_vibrato': False, 'bass_boost_level': 0.1, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        # --- Experimental & Sound FX ---
+        "Sci-Fi Energy Field": {
+            # Description: (SFX) High-speed vibrato and noise create a constant, shimmering hum suitable for energy shields or force fields.
+            'waveform_type': 'Triangle', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.4, 'vibrato_rate': 10.0, 'vibrato_depth': 3,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.1, 'noise_level': 0.1, 'distortion_level': 0.0, 'fm_modulation_depth': 0.05, 'fm_modulation_rate': 50
+        },
+        "Industrial Alarm": {
+            # Description: (SFX) Extreme vibrato rate on a sawtooth wave produces a harsh, metallic, dissonant alarm sound.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.2, 'vibrato_rate': 15.0, 'vibrato_depth': 8,
+            'smooth_notes': False, 'continuous_vibrato': False, 'bass_boost_level': 0.3, 'noise_level': 0.2, 'distortion_level': 0.3, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Laser Charge-Up": {
+            # Description: (SFX) Extreme vibrato depth creates a dramatic, rising pitch effect, perfect for sci-fi weapon sounds.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.3, 'vibrato_rate': 4.0, 'vibrato_depth': 25,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.2, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Unstable Machine Core": {
+            # Description: (SFX) Maximum depth and distortion create a chaotic, atonal noise, simulating a machine on the verge of exploding.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.5, 'vibrato_rate': 1.0, 'vibrato_depth': 50,
+            'smooth_notes': False, 'continuous_vibrato': True, 'bass_boost_level': 0.5, 'noise_level': 0.3, 'distortion_level': 0.4, 'fm_modulation_depth': 0.5, 'fm_modulation_rate': 10
+        },
+        "Hardcore Gabber Kick": {
+            # Description: (Experimental) Maximum bass boost and distortion create an overwhelmingly powerful, clipped kick drum sound.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.1, 'vibrato_rate': 0, 'vibrato_depth': 0,
+            'smooth_notes': False, 'continuous_vibrato': False, 'bass_boost_level': 0.8, 'noise_level': 0.2, 'distortion_level': 0.5, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        # --- Utility ---
+        "Generic Chiptune Loop": {
+            # Description: A well-balanced, pleasant square wave lead that serves as a great starting point for custom sounds.
+            'waveform_type': 'Square', 'pulse_width': 0.25, 'envelope_type': 'Plucky (AD Envelope)', 'decay_time_s': 0.2, 'vibrato_rate': 5.5, 'vibrato_depth': 4,
+            'smooth_notes': True, 'continuous_vibrato': True, 'bass_boost_level': 0.25, 'noise_level': 0.0, 'distortion_level': 0.0, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        },
+        "Dark/Boss Atmosphere": {
+            # Description: An aggressive sawtooth with heavy bass and distortion, perfect for tense or menacing background music.
+            'waveform_type': 'Sawtooth', 'pulse_width': 0.5, 'envelope_type': 'Sustained (Full Decay)', 'decay_time_s': 0.35, 'vibrato_rate': 7.0, 'vibrato_depth': 12,
+            'smooth_notes': False, 'continuous_vibrato': False, 'bass_boost_level': 0.4, 'noise_level': 0.15, 'distortion_level': 0.25, 'fm_modulation_depth': 0.0, 'fm_modulation_rate': 0.0
+        }
+    }
 
     app = gr.Blocks(theme=gr.themes.Base())
     
@@ -1041,16 +1282,98 @@ if __name__ == "__main__":
                     value="44100"
                 )
 
-                # --- NEW: 8-bit Synthesizer Settings ---
+                # --- 8-bit Synthesizer Settings ---
+                #
+                # =================================================================================
+                # === 8-Bit Synthesizer Parameter Guide ===
+                # =================================================================================
+                #
+                # --- Basic Tone Shaping ---
+                #
+                # Waveform Type: The fundamental timbre of the sound.
+                #   - Square: The classic, bright, somewhat hollow sound of the NES. Its tone is heavily modified by Pulse Width.
+                #   - Sawtooth: Aggressive, buzzy, and rich. Great for intense leads or gritty basslines.
+                #   - Triangle: Soft, pure, and flute-like. Often used for basslines or gentler melodies.
+                #
+                # Pulse Width (Square Wave Only): Modifies the character of the Square wave.
+                #   - Low (near 0.1) or High (near 0.9): Creates a thin, sharp, or nasal sound. A common choice for classic leads.
+                #   - Mid (near 0.5): A "perfect" square wave. The sound is full, round, and most robust.
+                #
+                # Envelope Type: Shapes the volume of each note over its duration.
+                #   - Plucky (AD): Creates a percussive, short sound that attacks instantly and then fades. Ideal for fast melodies and arpeggios.
+                #   - Sustained (Full Decay): Creates a held-out sound that lasts for the note's full duration. Ideal for pads and atmospheric sounds.
+                #
+                # Decay Time (s): Controls how long a note's sound lasts (in the Plucky envelope).
+                #   - Low: Very short, staccato notes.
+                #   - High: Longer, more resonant notes that can bleed into each other.
+                #
+                # Bass Boost Level: Mixes in a sub-octave (a square wave one octave lower).
+                #   - Low (or 0): The pure, original waveform.
+                #   - High: Adds significant weight, thickness, and power to the sound.
+                #
+                # --- Modulation & Performance ---
+                #
+                # Vibrato Rate (Hz): The SPEED of the pitch wobble.
+                #   - Low: A slow, gentle wavering effect.
+                #   - High (8Hz+): A fast, frantic buzzing or trembling effect. Can create "ring-mod" style sounds at extreme values.
+                #
+                # Vibrato Depth (Hz): The INTENSITY of the pitch wobble.
+                #   - Low (or 0): A very subtle effect, or no vibrato at all.
+                #   - High: An extreme, dramatic pitch bend. Can sound chaotic or like a siren at extreme values.
+                #
+                # Smooth Notes (Checkbox):
+                #   - Enabled: Applies a tiny fade-in/out to reduce clicking artifacts. Makes the sound slightly softer but cleaner.
+                #   - Disabled: More abrupt, harsh note onsets. Can be desirable for an aggressive sound.
+                #
+                # Continuous Vibrato (Checkbox):
+                #   - Enabled: The vibrato is smooth and connected across a musical phrase, creating a "singing" or legato effect.
+                #   - Disabled: The vibrato resets on each new note, creating a bouncy, per-note, staccato effect (key for the "Mario" style).
+                #
+                # --- FX & Advanced Synthesis ---
+                #
+                # Noise Level: Mixes in white noise with the main waveform.
+                #   - Low (or 0): No noise.
+                #   - High: Adds "air," "grit," or a "hissing" quality. Essential for simulating percussion or creating wind-like sound effects.
+                #
+                # Distortion Level: Applies a wave-shaping algorithm to make the sound harsher.
+                #   - Low (or 0): The clean, original sound.
+                #   - High: Progressively crushes and saturates the waveform, creating a very aggressive, "fuzzy" or "broken" tone.
+                #
+                # FM Depth (Frequency Modulation): Controls the intensity of the frequency modulation.
+                #   - Low (or 0): No FM effect.
+                #   - High: The main frequency is more heavily altered by the FM Rate, creating complex, bell-like, metallic, or dissonant tones.
+                #
+                # FM Rate (Frequency Modulation): Controls the speed of the modulating oscillator.
+                #   - Low: Creates a slow, vibrato-like or "wobbling" FM effect.
+                #   - High: Creates fast modulation, resulting in bright, complex, often metallic harmonics and sidebands.
+                # =================================================================================
+                #
                 with gr.Accordion("8-bit Synthesizer Settings", open=False, visible=False) as synth_8bit_settings:
+                    # --- ADDED: Preset selector dropdown ---
+                    s8bit_preset_selector = gr.Dropdown(
+                        choices=["Custom"] + list(S8BIT_PRESETS.keys()),
+                        value="Custom",
+                        label="Style Preset",
+                        info="Select a preset to auto-fill the settings below. Choose 'Custom' for manual control.\nFor reference and entertainment only. These presets are not guaranteed to be perfectly accurate."
+                    )
+                    
                     s8bit_waveform_type = gr.Dropdown(['Square', 'Sawtooth', 'Triangle'], value='Square', label="Waveform Type")
+                    s8bit_pulse_width = gr.Slider(0.01, 0.99, value=0.5, step=0.01, label="Pulse Width (Square Wave Only)")
                     s8bit_envelope_type = gr.Dropdown(['Plucky (AD Envelope)', 'Sustained (Full Decay)'], value='Plucky (AD Envelope)', label="Envelope Type")
-                    s8bit_decay_time_s = gr.Slider(0.01, 0.5, value=0.1, step=0.01, label="Decay Time (s)")
-                    s8bit_pulse_width = gr.Slider(0.01, 0.99, value=0.5, step=0.01, label="Pulse Width")
+                    s8bit_decay_time_s = gr.Slider(0.01, 0.6, value=0.1, step=0.01, label="Decay Time (s)")
                     s8bit_vibrato_rate = gr.Slider(0, 20, value=5, label="Vibrato Rate (Hz)")
                     s8bit_vibrato_depth = gr.Slider(0, 50, value=0, label="Vibrato Depth (Hz)")
                     s8bit_bass_boost_level = gr.Slider(minimum=0.0, maximum=1.0, value=0.0, step=0.1, label="Bass Boost Level", info="Adjusts the volume of the sub-octave. 0 is off.")
-
+                    s8bit_smooth_notes = gr.Checkbox(value=True, label="Smooth Notes", info="Applies a tiny fade-in/out to notes to reduce clicking.")
+                    s8bit_continuous_vibrato = gr.Checkbox(value=True, label="Continuous Vibrato", info="Prevents vibrato from resetting on each note.")
+                    
+                    # --- New accordion for advanced effects ---
+                    with gr.Accordion("Advanced Synthesis & FX", open=False):
+                        s8bit_noise_level = gr.Slider(minimum=0.0, maximum=1.0, value=0.0, step=0.05, label="Noise Level", info="Mixes in white noise. Great for percussion or adding 'air'.")
+                        s8bit_distortion_level = gr.Slider(minimum=0.0, maximum=0.9, value=0.0, step=0.05, label="Distortion Level", info="Applies wave-shaping distortion for a grittier, harsher sound.")
+                        s8bit_fm_modulation_depth = gr.Slider(minimum=0.0, maximum=1.0, value=0.0, step=0.05, label="FM Depth", info="Depth of Frequency Modulation. Creates complex, metallic, or bell-like tones.")
+                        s8bit_fm_modulation_rate = gr.Slider(minimum=0.0, maximum=500.0, value=0.0, step=1.0, label="FM Rate", info="Rate of Frequency Modulation. Higher values create brighter, more complex harmonics.")
+                        
                 # --- Original Advanced Options (Now tied to Piano-Specific) ---
                 with gr.Accordion("Advanced MIDI Rendering Options", open=False) as advanced_rendering_options:
                     render_with_sustains = gr.Checkbox(label="Apply sustain pedal effects (if present)", value=True)
@@ -1079,8 +1402,8 @@ if __name__ == "__main__":
                     output_midi = gr.File(label="Download Processed MIDI File", file_types=[".mid"])
                     output_midi_md5 = gr.Textbox(label="Output MIDI MD5 Hash")
                 output_midi_summary = gr.Textbox(label="MIDI metadata summary", lines=4)
-
-        # --- Define all input components for the click event ---
+                
+        # Define all input components for the click event, excluding the preset selector which is not a direct input to the final processing.
         all_inputs = [
             input_file, 
             enable_stereo_processing,
@@ -1091,13 +1414,23 @@ if __name__ == "__main__":
             render_with_sustains, merge_misaligned_notes, custom_render_patch, render_align,
             render_transpose_value, render_transpose_to_C4, render_output_as_solo_piano, render_remove_drums,
             s8bit_waveform_type, s8bit_envelope_type, s8bit_decay_time_s, 
-            s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth, s8bit_bass_boost_level
+            s8bit_pulse_width, s8bit_vibrato_rate, s8bit_vibrato_depth, s8bit_bass_boost_level,
+            s8bit_smooth_notes, s8bit_continuous_vibrato,
+            s8bit_noise_level, s8bit_distortion_level, s8bit_fm_modulation_depth, s8bit_fm_modulation_rate
         ]
         all_outputs = [
             output_midi_md5, output_midi_title, output_midi_summary, 
             output_midi, output_audio, output_plot, output_song_description
         ]
         
+        # Define the output components for the preset updater function.
+        s8bit_updater_outputs = [
+            s8bit_waveform_type, s8bit_pulse_width, s8bit_envelope_type,
+            s8bit_decay_time_s, s8bit_vibrato_rate, s8bit_vibrato_depth,
+            s8bit_smooth_notes, s8bit_continuous_vibrato, s8bit_bass_boost_level,
+            s8bit_noise_level, s8bit_distortion_level, s8bit_fm_modulation_depth, s8bit_fm_modulation_rate
+        ]
+        
         # --- Event Handling ---
         submit_btn.click(
             process_and_render_file, 
@@ -1116,6 +1449,17 @@ if __name__ == "__main__":
             inputs=[transcription_method, soundfont_bank],
             outputs=[general_transcription_settings, synth_8bit_settings]
         )
+        
+        # --- Event listener for the preset selector ---
+        # When the preset dropdown changes, it calls the `apply_8bit_preset` function.
+        # The input to the function is the selected preset name.
+        # The outputs are all the individual 8-bit setting components that need to be updated.
+        s8bit_preset_selector.change(
+            fn=apply_8bit_preset,
+            inputs=[s8bit_preset_selector],
+            outputs=s8bit_updater_outputs
+        )
+
 
     # Launch the Gradio app
     app.queue().launch(inbrowser=True, debug=True)