Update app.py

app.py

@@ -3,63 +3,81 @@ import os
 import shutil
 import asyncio
 import librosa
-import librosa.display
 import soundfile as sf
 import numpy as np
-import time
 import zipfile
 import tempfile
-import matplotlib.pyplot as plt
 import matplotlib
 matplotlib.use('Agg')
 
+# ---------------------------
+# UI helpers
+# ---------------------------
+
 def update_output_visibility(choice):
     if "2 Stems" in choice:
-        return {
-            vocals_output: gr.update(visible=True),
-            drums_output: gr.update(visible=False),
-            bass_output: gr.update(visible=False),
-            other_output: gr.update(visible=True, label="Instrumental (No Vocals)")
-        }
-    elif "4 Stems" in choice:
-        return {
-            vocals_output: gr.update(visible=True),
-            drums_output: gr.update(visible=True),
-            bass_output: gr.update(visible=True),
-            other_output: gr.update(visible=True, label="Other")
-        }
+        return (
+            gr.update(visible=True),
+            gr.update(visible=False),
+            gr.update(visible=False),
+            gr.update(visible=True, label="Instrumental (No Vocals)")
+        )
+    else:  # 4 stems
+        return (
+            gr.update(visible=True),
+            gr.update(visible=True),
+            gr.update(visible=True),
+            gr.update(visible=True, label="Other")
+        )
+
+# ---------------------------
+# Stem separation (Demucs)
+# ---------------------------
 
 async def separate_stems(audio_file_path, stem_choice, progress=gr.Progress(track_tqdm=True)):
-    if audio_file_path is None: raise gr.Error("No audio file uploaded!")
+    # outputs: [vocals_out, drums_out, bass_out, other_out, status_log]
+    if audio_file_path is None:
+        raise gr.Error("No audio file uploaded!")
     log_history = "Starting separation...\n"
-    yield { status_log: log_history, progress_bar: progress(0, desc="Starting...", visible=True) }
+    yield (gr.update(), gr.update(), gr.update(), gr.update(), log_history)
+
     try:
         progress(0.05, desc="Preparing audio file...")
-        log_history += "Preparing audio file...\n"; yield { status_log: log_history, progress_bar: progress(0.05, desc="Preparing...") }
+        log_history += "Preparing audio file...\n"
+        yield (gr.update(), gr.update(), gr.update(), gr.update(), log_history)
+
         original_filename_base = os.path.basename(audio_file_path).rsplit('.', 1)[0]
         stable_input_path = f"stable_input_{original_filename_base}.wav"
+        # Ensure a .wav input for Demucs (demucs can read many formats, but filepath stability helps)
         shutil.copy(audio_file_path, stable_input_path)
 
         model_arg = "--two-stems=vocals" if "2 Stems" in stem_choice else ""
         output_dir = "separated"
-        if os.path.exists(output_dir): shutil.rmtree(output_dir)
+        if os.path.exists(output_dir):
+            shutil.rmtree(output_dir)
 
-        command = f"python3 -m demucs {model_arg} -o \"{output_dir}\" \"{stable_input_path}\""
-        log_history += f"Running Demucs command: {command}\n(This may take a minute or more depending on track length)\n";
-        yield { status_log: log_history, progress_bar: progress(0.2, desc="Running Demucs...") }
+        command = f"python -m demucs {model_arg} -o \"{output_dir}\" \"{stable_input_path}\""
+        log_history += f"Running Demucs command: {command}\n"
+        log_history += "(This may take a minute or more depending on track length)\n"
+        yield (gr.update(), gr.update(), gr.update(), gr.update(), log_history)
 
+        progress(0.2, desc="Running Demucs...")
         process = await asyncio.create_subprocess_shell(
-            command, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE)
+            command, stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE
+        )
         stdout, stderr = await process.communicate()
 
         if process.returncode != 0:
-            raise gr.Error(f"Demucs failed. Error: {stderr.decode()[:500]}")
+            raise gr.Error(f"Demucs failed. Error: {stderr.decode(errors='ignore')[:800]}")
 
-        log_history += "Demucs finished. Locating stem files...\n"; yield { status_log: log_history, progress_bar: progress(0.8, desc="Locating stems...") }
-        stable_filename_base = os.path.basename(stable_input_path).rsplit('.', 1)[0]
+        log_history += "Demucs finished. Locating stem files...\n"
+        progress(0.8, desc="Locating stems...")
+        yield (gr.update(), gr.update(), gr.update(), gr.update(), log_history)
 
+        stable_filename_base = os.path.basename(stable_input_path).rsplit('.', 1)[0]
         subfolders = [f.name for f in os.scandir(output_dir) if f.is_dir()]
-        if not subfolders: raise gr.Error("Demucs output folder structure not found!")
+        if not subfolders:
+            raise gr.Error("Demucs output folder structure not found!")
         model_folder_name = subfolders[0]
         stems_path = os.path.join(output_dir, model_folder_name, stable_filename_base)
 
@@ -67,197 +85,328 @@ async def separate_stems(audio_file_path, stem_choice, progress=gr.Progress(trac
             raise gr.Error(f"Demucs output directory was not found! Looked for: {stems_path}")
 
         vocals_path = os.path.join(stems_path, "vocals.wav") if os.path.exists(os.path.join(stems_path, "vocals.wav")) else None
-        drums_path = os.path.join(stems_path, "drums.wav") if os.path.exists(os.path.join(stems_path, "drums.wav")) else None
-        bass_path = os.path.join(stems_path, "bass.wav") if os.path.exists(os.path.join(stems_path, "bass.wav")) else None
-        other_filename = "no_vocals.wav" if "2 Stems" in stem_choice else "other.wav"
-        other_path = os.path.join(stems_path, other_filename) if os.path.exists(os.path.join(stems_path, other_filename)) else None
-
-        os.remove(stable_input_path)
-
-        log_history += "✅ Stem separation complete!\n";
-        yield {
-            status_log: log_history,
-            progress_bar: progress(1, desc="Complete!", visible=False), # Hide progress bar when done
-            vocals_output: gr.update(value=vocals_path),
-            drums_output: gr.update(value=drums_path),
-            bass_output: gr.update(value=bass_path),
-            other_output: gr.update(value=other_path)
-        }
+        drums_path  = os.path.join(stems_path, "drums.wav")  if os.path.exists(os.path.join(stems_path, "drums.wav"))  else None
+        bass_path   = os.path.join(stems_path, "bass.wav")   if os.path.exists(os.path.join(stems_path, "bass.wav"))   else None
+        other_name  = "no_vocals.wav" if "2 Stems" in stem_choice else "other.wav"
+        other_path  = os.path.join(stems_path, other_name)   if os.path.exists(os.path.join(stems_path, other_name))   else None
+
+        try:
+            os.remove(stable_input_path)
+        except Exception:
+            pass
+
+        log_history += "✅ Stem separation complete!\n"
+        yield (
+            gr.update(value=vocals_path),
+            gr.update(value=drums_path),
+            gr.update(value=bass_path),
+            gr.update(value=other_path),
+            log_history
+        )
+
     except Exception as e:
-        print(f"An error occurred during separation: {e}")
-        yield { status_log: log_history + f"❌ ERROR: {e}", progress_bar: gr.update(visible=False) } # Hide progress bar on error
+        err = f"❌ ERROR: {e}"
+        print(f"Separation error: {e}")
+        yield (gr.update(), gr.update(), gr.update(), gr.update(), log_history + err)
+
+# ---------------------------
+# Slicing (BPM override + Quantized grid)
+# ---------------------------
+
+def _grid_beats_per_step(grid_label: str) -> float:
+    # "1/16 (Sixteenth)" -> "1/16"
+    tok = grid_label.split(" ")[0].strip()
+    mapping = {"1/1": 4.0, "1/2": 2.0, "1/4": 1.0, "1/8": 0.5, "1/16": 0.25}
+    return mapping.get(tok, 0.25)
+
+def _load_audio_any(stem_input):
+    """
+    Accepts a filepath string OR (sr, numpy_array) and returns (sr, mono_float_array).
+    We use filepath everywhere in this app to keep memory stable.
+    """
+    if stem_input is None:
+        return None, None
+    if isinstance(stem_input, str):
+        y, sr = librosa.load(stem_input, sr=None, mono=False)
+    else:
+        sr, y = stem_input
+    y = librosa.util.buf_to_float(y)
+    y_mono = librosa.to_mono(y) if y.ndim > 1 else y
+    return sr, y_mono
+
+def slice_stem_real(
+    stem_input,
+    loop_choice,
+    sensitivity,
+    stem_name,
+    progress_fn=None,
+    bpm_override_val: int = 0,
+    quantize: bool = True,
+    grid_label: str = "1/16 (Sixteenth)",
+):
+    sr, y_mono = _load_audio_any(stem_input)
+    if sr is None or y_mono is None:
+        return None, None
 
-def slice_stem_real(stem_audio_data, loop_choice, sensitivity, stem_name, progress_fn=None):
-    if stem_audio_data is None: return None, None
-    sample_rate, y_int = stem_audio_data; y = librosa.util.buf_to_float(y_int)
-    y_mono = librosa.to_mono(y.T) if y.ndim > 1 else y
     if progress_fn: progress_fn(0.1, desc="Detecting BPM...")
-    tempo, beats = librosa.beat.beat_track(y=y_mono, sr=sample_rate)
-    bpm = 120 if tempo is None else np.round(tempo); bpm_int = int(bpm.item())
-    if bpm_int == 0: bpm_int = 120; print("BPM detection failed, defaulting to 120 BPM.")
-    print(f"Detected BPM for {stem_name}: {bpm_int}")
-    output_files = []; loops_dir = tempfile.mkdtemp()
+    tempo, _ = librosa.beat.beat_track(y=y_mono, sr=sr)
+    det_bpm = int(np.round(tempo)) if tempo and tempo > 0 else 120
+    bpm = int(bpm_override_val) if bpm_override_val and bpm_override_val > 0 else det_bpm
+    if bpm <= 0:
+        bpm = 120
+
+    output_files = []
+    loops_dir = tempfile.mkdtemp()
+
     if "One-Shots" in loop_choice:
         if progress_fn: progress_fn(0.3, desc="Finding transients...")
-        onset_frames = librosa.onset.onset_detect(y=y_mono, sr=sample_rate, delta=sensitivity, wait=1, pre_avg=1, post_avg=1, post_max=1)
+        onset_frames = librosa.onset.onset_detect(
+            y=y_mono, sr=sr, delta=sensitivity, wait=1, pre_avg=1, post_avg=1, post_max=1
+        )
         onset_samples = librosa.frames_to_samples(onset_frames)
+
+        # Quantize onsets to musical grid if enabled
+        if quantize and len(onset_samples) > 0:
+            beats_per_step = _grid_beats_per_step(grid_label)
+            samples_per_beat = sr * (60.0 / bpm)
+            step = max(1, int(round(samples_per_beat * beats_per_step)))
+            q = np.clip(np.round(onset_samples / step) * step, 0, len(y_mono) - 1).astype(int)
+            q = np.unique(q)  # dedupe after snapping
+            onset_samples = q
+
         if progress_fn: progress_fn(0.5, desc="Slicing one-shots...")
+
         if len(onset_samples) > 0:
             num_onsets = len(onset_samples)
+            min_len = max(1, int(0.02 * sr))  # 20ms min slice guard
             for i, start_sample in enumerate(onset_samples):
-                end_sample = onset_samples[i+1] if i+1 < num_onsets else len(y)
-                slice_data = y[start_sample:end_sample]
+                end_sample = onset_samples[i+1] if i+1 < num_onsets else len(y_mono)
+                if end_sample - start_sample < min_len:
+                    continue
+                slice_data = y_mono[start_sample:end_sample]
                 filename = os.path.join(loops_dir, f"{stem_name}_one_shot_{i+1:03d}.wav")
-                sf.write(filename, slice_data, sample_rate, subtype='PCM_16')
+                sf.write(filename, slice_data, sr, subtype='PCM_16')
                 output_files.append(filename)
                 if progress_fn and num_onsets > 1:
                     progress_fn(0.5 + (i / (num_onsets - 1) * 0.5), desc=f"Exporting slice {i+1}/{num_onsets}...")
     else:
-        bars = int(loop_choice.split(" ")[0]); seconds_per_beat = 60.0 / bpm_int; seconds_per_bar = seconds_per_beat * 4
-        loop_duration_seconds = seconds_per_bar * bars; loop_duration_samples = int(loop_duration_seconds * sample_rate)
-        if progress_fn: progress_fn(0.4, desc=f"Slicing into {bars}-bar loops...")
-        num_loops = len(y) // loop_duration_samples
-        if num_loops == 0: print(f"Audio for {stem_name} is too short for {bars}-bar loops at {bpm_int} BPM."); return None, None
+        # Grid-true by construction; honor BPM override
+        bars = int(loop_choice.split(" ")[0])
+        seconds_per_beat = 60.0 / bpm
+        seconds_per_bar = seconds_per_beat * 4
+        loop_duration_seconds = seconds_per_bar * bars
+        loop_duration_samples = int(loop_duration_seconds * sr)
+        if progress_fn: progress_fn(0.4, desc=f"Slicing into {bars}-bar loops @ {bpm} BPM...")
+        num_loops = len(y_mono) // loop_duration_samples
+        if num_loops == 0:
+            return None, None
         for i in range(num_loops):
-            start_sample = i * loop_duration_samples; end_sample = start_sample + loop_duration_samples
-            slice_data = y[start_sample:end_sample]
-            filename = os.path.join(loops_dir, f"{stem_name}_{bars}bar_loop_{i+1:03d}_{bpm_int}bpm.wav")
-            sf.write(filename, slice_data, sample_rate, subtype='PCM_16')
+            start_sample = i * loop_duration_samples
+            end_sample = start_sample + loop_duration_samples
+            slice_data = y_mono[start_sample:end_sample]
+            filename = os.path.join(loops_dir, f"{stem_name}_{bars}bar_loop_{i+1:03d}_{bpm}bpm.wav")
+            sf.write(filename, slice_data, sr, subtype='PCM_16')
             output_files.append(filename)
             if progress_fn and num_loops > 1:
                 progress_fn(0.4 + (i / (num_loops - 1) * 0.6), desc=f"Exporting loop {i+1}/{num_loops}...")
-    if not output_files: return None, None
+
+    if not output_files:
+        return None, None
     return output_files, loops_dir
 
-async def slice_all_and_zip_real(vocals, drums, bass, other, loop_choice, sensitivity, progress=gr.Progress(track_tqdm=True)):
+# ---------------------------
+# Batch wrapper
+# ---------------------------
+
+async def slice_all_and_zip_real(vocals, drums, bass, other, loop_choice, sensitivity,
+                                 bpm_over, quantize_on, grid_sel,
+                                 progress=gr.Progress(track_tqdm=True)):
+    # outputs: [status_log, download_zip_file]
     log_history = "Starting batch slice...\n"
-    yield { status_log: log_history, progress_bar: progress(0, desc="Starting...", visible=True) }
-    await asyncio.sleep(0.1)
+    yield (log_history, gr.update(visible=False))
+
+    await asyncio.sleep(0.05)
     stems_to_process = {"vocals": vocals, "drums": drums, "bass": bass, "other": other}
+    present = {k: v for k, v in stems_to_process.items() if v}
+    if not present:
+        raise gr.Error("No stems to process! Please separate stems first.")
+
     zip_path = "Loop_Architect_Pack.zip"
-    num_stems = sum(1 for data in stems_to_process.values() if data is not None)
-    if num_stems == 0: raise gr.Error("No stems to process! Please separate stems first.")
     all_temp_dirs = []
     try:
         with zipfile.ZipFile(zip_path, 'w') as zf:
-            processed_count = 0
-            for name, data in stems_to_process.items():
-                if data is not None:
-                    log_history += f"--- Slicing {name} stem ---\n"; yield { status_log: log_history }
-                    def update_main_progress(p, desc=""):
-                        overall_progress = (processed_count + p) / num_stems
-                        progress(overall_progress, desc=f"Slicing {name}: {desc}", visible=True)
-
-                    sliced_files, temp_dir = slice_stem_real((data[0], data[1]), loop_choice, sensitivity, name, progress_fn=update_main_progress)
-
-                    if sliced_files:
-                        log_history += f"Generated {len(sliced_files)} slices for {name}.\n"; yield { status_log: log_history }
-                        all_temp_dirs.append(temp_dir)
-                        for loop_file in sliced_files:
-                            arcname = os.path.join(name, os.path.basename(loop_file))
-                            zf.write(loop_file, arcname)
-                    else:
-                        log_history += f"No slices generated for {name}.\n"; yield { status_log: log_history }
-
-                    processed_count += 1
-                    yield { status_log: log_history, progress_bar: progress(processed_count / num_stems, desc=f"Finished {name}", visible=True) }
-
-        log_history += "Packaging complete!\n";
-        yield {
-            status_log: log_history + "✅ Pack ready for download!",
-            progress_bar: progress(1, desc="Pack Ready!", visible=False),
-            download_zip_file: gr.update(value=zip_path, visible=True)
-        }
+            processed, total = 0, len(present)
+            for name, data in present.items():
+                log_history += f"--- Slicing {name} stem ---\n"
+                yield (log_history, gr.update(visible=False))
+
+                def update_main_progress(p, desc=""):
+                    progress((processed + max(0.01, p)) / total, desc=f"{name}: {desc}")
+
+                sliced_files, temp_dir = slice_stem_real(
+                    data, loop_choice, sensitivity, name,
+                    progress_fn=update_main_progress,
+                    bpm_override_val=int(bpm_over),
+                    quantize=bool(quantize_on),
+                    grid_label=grid_sel
+                )
+                if temp_dir:
+                    all_temp_dirs.append(temp_dir)
+                if sliced_files:
+                    log_history += f"Generated {len(sliced_files)} slices for {name}.\n"
+                    for loop_file in sliced_files:
+                        zf.write(loop_file, os.path.join(name, os.path.basename(loop_file)))
+                else:
+                    log_history += f"No slices generated for {name}.\n"
+
+                processed += 1
+                yield (log_history, gr.update(visible=False))
+
+        log_history += "Packaging complete! ✅ Pack ready for download.\n"
+        yield (log_history, gr.update(value=zip_path, visible=True))
+
     except Exception as e:
-         print(f"An error occurred during slice all: {e}")
-         yield { status_log: log_history + f"❌ ERROR: {e}", progress_bar: gr.update(visible=False) }
+        err = f"❌ ERROR: {e}"
+        print(f"Batch slice error: {e}")
+        yield (log_history + err, gr.update(visible=False))
     finally:
         for d in all_temp_dirs:
             if d and os.path.exists(d):
                 shutil.rmtree(d)
 
-# --- Create the full Gradio Interface ---
+# ---------------------------
+# Gradio UI
+# ---------------------------
+
 with gr.Blocks(theme=gr.themes.Default(primary_hue="blue", secondary_hue="red")) as demo:
-    gr.Markdown("# 🎵 Loop Architect")
+    gr.Markdown("# 🎵 Loop Architect — SALT PRØPHET Edition")
+
     with gr.Row():
         with gr.Column(scale=1):
-            gr.Markdown("### 1. Separate Stems")
+            gr.Markdown("### 1) Separate Stems")
             audio_input = gr.Audio(type="filepath", label="Upload a Track")
-            stem_options = gr.Radio(["4 Stems (Vocals, Drums, Bass, Other)", "2 Stems (Vocals + Instrumental)"], label="Separation Type", value="4 Stems (Vocals, Drums, Bass, Other)")
-            submit_button = gr.Button("Separate Stems")
-
-            with gr.Accordion("Slicing Options", open=True):
-                loop_options_radio = gr.Radio(["One-Shots (All Transients)", "4 Bar Loops", "8 Bar Loops"], label="Slice Type", value="One-Shots (All Transients)")
-                sensitivity_slider = gr.Slider(minimum=0.01, maximum=0.5, value=0.05, step=0.01, label="One-Shot Sensitivity", info="Lower values = more slices")
-
-            gr.Markdown("### 3. Create Pack")
+            stem_options = gr.Radio(
+                ["4 Stems (Vocals, Drums, Bass, Other)", "2 Stems (Vocals + Instrumental)"],
+                label="Separation Type",
+                value="4 Stems (Vocals, Drums, Bass, Other)"
+            )
+            submit_button = gr.Button("Separate Stems", variant="secondary")
+
+            with gr.Accordion("2) Slicing Options", open=True):
+                loop_options_radio = gr.Radio(
+                    ["One-Shots (All Transients)", "4 Bar Loops", "8 Bar Loops"],
+                    label="Slice Type",
+                    value="One-Shots (All Transients)"
+                )
+                sensitivity_slider = gr.Slider(
+                    minimum=0.01, maximum=0.5, value=0.05, step=0.01,
+                    label="One-Shot Sensitivity", info="Lower values = more slices"
+                )
+                bpm_override = gr.Slider(
+                    minimum=0, maximum=240, value=0, step=1,
+                    label="BPM Override (0 = auto-detect)"
+                )
+                quantize_toggle = gr.Checkbox(
+                    label="Quantize One-Shots to Grid", value=True
+                )
+                grid_select = gr.Dropdown(
+                    choices=["1/1 (Whole)", "1/2 (Half)", "1/4 (Quarter)", "1/8 (Eighth)", "1/16 (Sixteenth)"],
+                    value="1/16 (Sixteenth)",
+                    label="Grid Resolution"
+                )
+
+            gr.Markdown("### 3) Create Pack")
             slice_all_button = gr.Button("Slice All Stems & Create Pack", variant="primary")
             download_zip_file = gr.File(label="Download Your Loop Pack", visible=False)
 
             gr.Markdown("### Status")
-            # --- THIS IS THE FIX --- Initialize without any arguments
-            progress_bar = gr.Progress()
-            status_log = gr.Textbox(label="Status Log", lines=10, interactive=False)
+            status_log = gr.Textbox(label="Status Log", lines=12, interactive=False)
 
         with gr.Column(scale=2):
             with gr.Accordion("Separated Stems", open=True):
                 with gr.Row():
-                    vocals_output = gr.Audio(label="Vocals", scale=4)
+                    vocals_output = gr.Audio(type="filepath", label="Vocals", scale=4)
                     slice_vocals_btn = gr.Button("Slice Vocals", scale=1)
                 with gr.Row():
-                    drums_output = gr.Audio(label="Drums", scale=4)
+                    drums_output = gr.Audio(type="filepath", label="Drums", scale=4)
                     slice_drums_btn = gr.Button("Slice Drums", scale=1)
                 with gr.Row():
-                    bass_output = gr.Audio(label="Bass", scale=4)
+                    bass_output = gr.Audio(type="filepath", label="Bass", scale=4)
                     slice_bass_btn = gr.Button("Slice Bass", scale=1)
                 with gr.Row():
-                    other_output = gr.Audio(label="Other / Instrumental", scale=4)
+                    other_output = gr.Audio(type="filepath", label="Other / Instrumental", scale=4)
                     slice_other_btn = gr.Button("Slice Other", scale=1)
-            gr.Markdown("### Sliced Loops / Samples (Preview)")
-            loop_gallery = gr.Gallery(label="Generated Loops Preview", columns=8, object_fit="contain", height="auto", preview=True)
 
-    # --- Define Event Listeners ---
-    def slice_and_display(stem_data, loop_choice, sensitivity, stem_name):
-        log_history = f"Slicing {stem_name}...\n"
-        # Make progress bar visible when starting
-        yield {
-            status_log: log_history,
-            progress_bar: gr.update(value=0, visible=True, label=f"Slicing {stem_name}...")
-        }
-
-        # Define how slice_stem_real updates the progress bar using gr.Progress directly
-        def update_single_progress(p, desc=""):
-             gr.Progress(track_tqdm=True)(p, desc=desc) # Pass progress updates
-
-        files, temp_dir = slice_stem_real(stem_data, loop_choice, sensitivity, stem_name, progress_fn=update_single_progress)
-
-        if temp_dir and os.path.exists(temp_dir):
-             shutil.rmtree(temp_dir)
+            gr.Markdown("### Sliced Files")
+            loops_files = gr.Files(label="Generated Loops / One-Shots")
 
-        yield {
-            loop_gallery: gr.update(value=files),
-            status_log: log_history + f"✅ Sliced {stem_name} into {len(files) if files else 0} pieces.",
-            progress_bar: gr.update(visible=False) # Hide progress bar when done
-        }
-
-    submit_event = submit_button.click(
+    # wire events
+    submit_button.click(
         fn=separate_stems,
         inputs=[audio_input, stem_options],
         outputs=[vocals_output, drums_output, bass_output, other_output, status_log]
     )
 
-    stem_options.change(fn=update_output_visibility, inputs=stem_options, outputs=[vocals_output, drums_output, bass_output, other_output])
+    stem_options.change(
+        fn=update_output_visibility,
+        inputs=stem_options,
+        outputs=[vocals_output, drums_output, bass_output, other_output]
+    )
 
-    slice_vocals_btn.click(fn=slice_and_display, inputs=[vocals_output, loop_options_radio, sensitivity_slider, gr.Textbox("vocals", visible=False)], outputs=[loop_gallery, status_log, progress_bar])
-    slice_drums_btn.click(fn=slice_and_display, inputs=[drums_output, loop_options_radio, sensitivity_slider, gr.Textbox("drums", visible=False)], outputs=[loop_gallery, status_log, progress_bar])
-    slice_bass_btn.click(fn=slice_and_display, inputs=[bass_output, loop_options_radio, sensitivity_slider, gr.Textbox("bass", visible=False)], outputs=[loop_gallery, status_log, progress_bar])
-    slice_other_btn.click(fn=slice_and_display, inputs=[other_output, loop_options_radio, sensitivity_slider, gr.Textbox("other", visible=False)], outputs=[loop_gallery, status_log, progress_bar])
+    def slice_and_display(stem_path, loop_choice, sensitivity, stem_name, bpm_over, quantize_on, grid_sel):
+        log_history = f"Slicing {stem_name}...\n"
+        def _p(p, desc=""):
+            gr.Progress(track_tqdm=True)(p, desc=desc)
+
+        files, temp_dir = slice_stem_real(
+            stem_path, loop_choice, sensitivity, stem_name,
+            progress_fn=_p,
+            bpm_override_val=int(bpm_over),
+            quantize=bool(quantize_on),
+            grid_label=grid_sel
+        )
+        if temp_dir and os.path.exists(temp_dir):
+            shutil.rmtree(temp_dir)
+
+        if files:
+            log_history += f"✅ Sliced {stem_name} into {len(files)} pieces."
+            return gr.update(value=files), log_history
+        else:
+            log_history += f"⚠️ No slices generated for {stem_name}."
+            return gr.update(value=None), log_history
+
+    slice_vocals_btn.click(
+        fn=slice_and_display,
+        inputs=[vocals_output, loop_options_radio, sensitivity_slider, gr.Textbox("vocals", visible=False),
+                bpm_override, quantize_toggle, grid_select],
+        outputs=[loops_files, status_log]
+    )
+    slice_drums_btn.click(
+        fn=slice_and_display,
+        inputs=[drums_output, loop_options_radio, sensitivity_slider, gr.Textbox("drums", visible=False),
+                bpm_override, quantize_toggle, grid_select],
+        outputs=[loops_files, status_log]
+    )
+    slice_bass_btn.click(
+        fn=slice_and_display,
+        inputs=[bass_output, loop_options_radio, sensitivity_slider, gr.Textbox("bass", visible=False),
+                bpm_override, quantize_toggle, grid_select],
+        outputs=[loops_files, status_log]
+    )
+    slice_other_btn.click(
+        fn=slice_and_display,
+        inputs=[other_output, loop_options_radio, sensitivity_slider, gr.Textbox("other", visible=False),
+                bpm_override, quantize_toggle, grid_select],
+        outputs=[loops_files, status_log]
+    )
 
-    slice_all_event = slice_all_button.click(
+    slice_all_button.click(
         fn=slice_all_and_zip_real,
-        inputs=[vocals_output, drums_output, bass_output, other_output, loop_options_radio, sensitivity_slider],
-        outputs=[download_zip_file, download_zip_file, status_log]
+        inputs=[vocals_output, drums_output, bass_output, other_output,
+                loop_options_radio, sensitivity_slider,
+                bpm_override, quantize_toggle, grid_select],
+        outputs=[status_log, download_zip_file]
     )
 
-# --- Launch the UI ---
-demo.launch()
+# Spaces calls launch() automatically
+demo.queue(concurrency_count=1, max_size=8).launch()