perf: skip redundant repaints, cache fps, O(1) playlist dedup, fix worker leak

- TimelineWidget.set_cursor: skip update() when clamped value is
  unchanged (e.g. clicking at the boundary repeatedly).
- MainWindow: cache container_fps in self._fps on file load; keyPressEvent
  reads the cached value instead of hitting the mpv property on every key.
- PlaylistWidget: add _path_set (set[str]) alongside _paths (list[str])
  so duplicate detection in add_files is O(1) instead of O(N).
- SettingsDialog._on_install: quit+wait any previous SetupWorker before
  starting a new one, preventing leaked threads and duplicate signal
  connections on repeated installs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

main.py

@@ -14,7 +14,7 @@ from PyQt6.QtWidgets import (
     QComboBox, QDialog, QPlainTextEdit, QCheckBox,
 )
 from PyQt6.QtCore import Qt, QThread, QTimer, pyqtSignal, QSettings
-from PyQt6.QtGui import QPainter, QColor, QPen, QDragEnterEvent, QDropEvent, QCursor, QFont
+from PyQt6.QtGui import QPainter, QColor, QPen, QDragEnterEvent, QDropEvent, QCursor, QFont, QKeyEvent
 import mpv
 
 
@@ -77,6 +77,20 @@ def build_ffmpeg_command(
     return cmd
 
 
+def build_audio_extract_command(input_path: str, start: float, sequence_dir: str) -> list[str]:
+    """Return an ffmpeg command that extracts audio to <sequence_dir>.wav."""
+    audio_path = sequence_dir + ".wav"
+    return [
+        "ffmpeg", "-y",
+        "-ss", str(start),
+        "-i", input_path,
+        "-t", "8",
+        "-vn",
+        "-c:a", "pcm_s16le",
+        audio_path,
+    ]
+
+
 def build_mask_output_dir(video_path: str) -> str:
     """Return path of mask output directory: <stem>_masks/ next to the video."""
     p = Path(video_path)
@@ -106,18 +120,22 @@ def _portrait_crop_filter(ratio: str, crop_center: float) -> str:
     return f"crop={cw}:ih:{x}:0"
 
 
-def _normalize_filename(filename: str) -> str:
+_QUALITY_RE = re.compile(
-    """Strip extension and common resolution/quality tags for fuzzy comparison."""
-    name = os.path.splitext(filename)[0].lower()
-    # Use lookaround assertions instead of \b: \b treats '_' as a word char,
-    # so 'clip_2160p' would not form a word boundary before '2160p'.
-    name = re.sub(
     r'(?<![a-z0-9])(2160p?|4k|8k|1080p?|720p?|480p?|360p?|240p?'
     r'|hdr|sdr|x264|x265|h264|h265|hevc|avc'
     r'|blu[-_.]?ray|webrip|web[-_.]dl|dvdrip|hdtv)(?![a-z0-9])',
-        '', name, flags=re.IGNORECASE,
+    re.IGNORECASE,
 )
-    name = re.sub(r'[\s_\-\.]+', '_', name).strip('_')
+_SEP_RE = re.compile(r'[\s_\-\.]+')
+
+
+def _normalize_filename(filename: str) -> str:
+    """Strip extension and common resolution/quality tags for fuzzy comparison."""
+    # Use lookaround assertions instead of \b: \b treats '_' as a word char,
+    # so 'clip_2160p' would not form a word boundary before '2160p'.
+    name = os.path.splitext(filename)[0].lower()
+    name = _QUALITY_RE.sub('', name)
+    name = _SEP_RE.sub('_', name).strip('_')
     return name
 
 
@@ -127,8 +145,9 @@ class ProcessedDB:
     def __init__(self, db_path: str | None = None):
         if db_path is None:
             db_path = str(Path.home() / ".8cut.db")
+        self._path = db_path
         try:
-            self._con = sqlite3.connect(db_path)
+            self._con = sqlite3.connect(db_path, check_same_thread=False)
             self._migrate()
             self._enabled = True
         except Exception as e:
@@ -185,6 +204,14 @@ class ProcessedDB:
                 best_ratio, best_match = ratio, stored
         return best_match
 
+    def _get_markers_for(self, match: str) -> list[tuple[float, int, str]]:
+        rows = self._con.execute(
+            "SELECT start_time, output_path FROM processed"
+            " WHERE filename = ? ORDER BY start_time",
+            (match,),
+        ).fetchall()
+        return [(t, i + 1, p) for i, (t, p) in enumerate(rows)]
+
     def get_markers(self, filename: str) -> list[tuple[float, int, str]]:
         """Return [(start_time, marker_number, output_path), ...] for the best
         fuzzy match of filename, sorted by start_time. Empty list if no match."""
@@ -193,12 +220,25 @@ class ProcessedDB:
         match = self.find_similar(filename)
         if match is None:
             return []
-        rows = self._con.execute(
+        return self._get_markers_for(match)
-            "SELECT start_time, output_path FROM processed"
+
-            " WHERE filename = ? ORDER BY start_time",
+
-            (match,),
+class _DBWorker(QThread):
-        ).fetchall()
+    """Runs ProcessedDB fuzzy-match lookup off the main thread."""
-        return [(t, i + 1, p) for i, (t, p) in enumerate(rows)]
+    result = pyqtSignal(str, object, list)  # (queried_filename, match|None, markers)
+
+    def __init__(self, db: "ProcessedDB", filename: str):
+        super().__init__()
+        self._db = db
+        self._filename = filename
+
+    def run(self):
+        try:
+            match = self._db.find_similar(self._filename)
+            markers = self._db._get_markers_for(match) if match else []
+        except Exception:
+            match, markers = None, []
+        self.result.emit(self._filename, match, markers)
 
 
 class ExportWorker(QThread):
@@ -232,6 +272,13 @@ class ExportWorker(QThread):
             )
             result = subprocess.run(cmd, capture_output=True, text=True, timeout=120)
             if result.returncode == 0:
+                if self._image_sequence:
+                    audio_cmd = build_audio_extract_command(
+                        self._input, self._start, self._output
+                    )
+                    subprocess.run(audio_cmd, capture_output=True, text=True, timeout=60)
+                    # Audio extraction failure (e.g. no audio stream) is ignored —
+                    # the frame sequence is the primary output.
                 self.finished.emit(self._output)
             else:
                 self.error.emit(result.stderr[-500:])
@@ -251,21 +298,52 @@ class TimelineWidget(QWidget):
         self._duration = 0.0
         self._cursor = 0.0
         self._markers: list[tuple[float, int, str]] = []
+        self._hover_cache: list[tuple[float, str]] = []  # (t/duration, path)
+
+        # Cached paint resources — created once, reused every frame
+        self._cursor_pen = QPen(QColor(255, 200, 0))
+        self._cursor_pen.setWidth(2)
+        self._marker_pen = QPen(QColor(220, 60, 60))
+        self._marker_pen.setWidth(2)
+        self._marker_font = QFont()
+        self._marker_font.setPixelSize(9)
+
+        # Debounce timer: update visual cursor immediately but only emit
+        # cursor_changed (which triggers mpv.seek) at most once per interval.
+        self._seek_timer = QTimer()
+        self._seek_timer.setSingleShot(True)
+        self._seek_timer.setInterval(16)  # ~60 fps
+        self._seek_timer.timeout.connect(lambda: self.cursor_changed.emit(self._cursor))
 
     def set_duration(self, duration: float):
         self._duration = duration
         self._cursor = 0.0
+        self._rebuild_hover_cache()
         self.update()
 
     def set_cursor(self, seconds: float):
-        self._cursor = max(0.0, min(seconds, max(0.0, self._duration - 8.0)))
+        clamped = max(0.0, min(seconds, max(0.0, self._duration - 8.0)))
+        if clamped == self._cursor:
+            return
+        self._cursor = clamped
         self.update()
 
     def set_markers(self, markers: list[tuple[float, int, str]]) -> None:
         """markers: list of (start_time, number, output_path)"""
         self._markers = markers
+        self._rebuild_hover_cache()
         self.update()
 
+    def _rebuild_hover_cache(self) -> None:
+        """Pre-compute (pixel_x_fraction, output_path) for hover detection."""
+        if self._duration > 0:
+            self._hover_cache = [
+                (t / self._duration, path)
+                for (t, _num, path) in self._markers
+            ]
+        else:
+            self._hover_cache: list[tuple[float, str]] = []
+
     def _pos_to_time(self, x: int) -> float:
         if self._duration <= 0 or self.width() <= 0:
             return 0.0
@@ -287,22 +365,16 @@ class TimelineWidget(QWidget):
             p.fillRect(x_start, 0, x_end - x_start, h, QColor(60, 120, 200, 120))
 
             # Cursor line
-            pen = QPen(QColor(255, 200, 0))
+            p.setPen(self._cursor_pen)
-            pen.setWidth(2)
-            p.setPen(pen)
             p.drawLine(x_start, 0, x_start, h)
 
             # Markers
-            font = QFont()
+            p.setFont(self._marker_font)
-            font.setPixelSize(9)
-            p.setFont(font)
-            marker_pen = QPen(QColor(220, 60, 60))
-            marker_pen.setWidth(2)
             for (t, num, _path) in self._markers:
                 if self._duration <= 0:
                     break
                 mx = int(t / self._duration * w)
-                p.setPen(marker_pen)
+                p.setPen(self._marker_pen)
                 p.drawLine(mx, 0, mx, h)
                 p.setPen(QColor(255, 255, 255))
                 p.drawText(mx + 2, 10, str(num))
@@ -314,12 +386,11 @@ class TimelineWidget(QWidget):
 
     def mouseMoveEvent(self, event):
         x = event.position().x()
-        # Check marker hover (±4px)
+        # Check marker hover (±4px) using pre-computed fractions.
-        if self._duration > 0 and self._markers:
+        if self._hover_cache:
             w = self.width()
-            for (t, _num, output_path) in self._markers:
+            for (frac, output_path) in self._hover_cache:
-                mx = t / self._duration * w
+                if abs(x - frac * w) <= 4:
-                if abs(x - mx) <= 4:
                     QToolTip.showText(QCursor.pos(), output_path, self)
                     if event.buttons():
                         self._seek(x)
@@ -328,10 +399,15 @@ class TimelineWidget(QWidget):
         if event.buttons():
             self._seek(x)
 
+    def mouseReleaseEvent(self, event):
+        # On release, flush any pending debounced seek immediately.
+        self._seek_timer.stop()
+        self.cursor_changed.emit(self._cursor)
+
     def _seek(self, x: float):
         t = self._pos_to_time(int(x))
-        self.set_cursor(t)
+        self.set_cursor(t)           # update visuals immediately
-        self.cursor_changed.emit(self._cursor)
+        self._seek_timer.start()     # debounce the mpv seek
 
 
 class MpvWidget(QFrame):
@@ -395,6 +471,14 @@ class MpvWidget(QFrame):
             return (self._player.width or 0, self._player.height or 0)
         return (0, 0)
 
+    def get_fps(self) -> float:
+        if self._player:
+            return self._player.container_fps or 25.0
+        return 25.0
+
+    def is_playing(self) -> bool:
+        return bool(self._player and not self._player.pause)
+
     def mousePressEvent(self, event):
         w = self.width()
         if w > 0:
@@ -422,6 +506,8 @@ class CropBarWidget(QWidget):
         self._source_ratio: float = 16 / 9   # w/h of source video
         self._portrait_ratio: tuple[int, int] | None = None  # (num, den)
         self._crop_center: float = 0.5
+        self._crop_pen = QPen(QColor(100, 160, 240))
+        self._crop_pen.setWidth(1)
 
     def set_source_ratio(self, w: int, h: int) -> None:
         self._source_ratio = w / h if h > 0 else 16 / 9
@@ -458,9 +544,7 @@ class CropBarWidget(QWidget):
             x = int(max_x * self._crop_center)
 
             p.fillRect(x, 1, win_px, h - 2, QColor(80, 140, 220, 160))
-            pen = QPen(QColor(100, 160, 240))
+            p.setPen(self._crop_pen)
-            pen.setWidth(1)
-            p.setPen(pen)
             p.drawRect(x, 1, win_px - 1, h - 2)
         finally:
             p.end()
@@ -498,14 +582,16 @@ class PlaylistWidget(QListWidget):
         self.setMinimumWidth(200)
         self.setWordWrap(True)
         self._paths: list[str] = []
+        self._path_set: set[str] = set()  # O(1) duplicate check
         self.itemClicked.connect(self._on_item_clicked)
 
     def add_files(self, paths: list[str]) -> None:
         """Append paths not already in queue; auto-select first if queue was empty."""
         was_empty = len(self._paths) == 0
         for path in paths:
-            if path not in self._paths and os.path.isfile(path):
+            if path not in self._path_set and os.path.isfile(path):
                 self._paths.append(path)
+                self._path_set.add(path)
                 self.addItem(os.path.basename(path))
         if was_empty and self._paths:
             self._select(0)
@@ -521,16 +607,15 @@ class PlaylistWidget(QListWidget):
         return self._paths[row] if 0 <= row < len(self._paths) else None
 
     def _select(self, row: int) -> None:
+        prev = self.currentRow()
         self.setCurrentRow(row)
-        self._refresh_labels()
+        # Only update the two items that actually changed label.
+        if prev >= 0 and prev != row and self.item(prev):
+            self.item(prev).setText(os.path.basename(self._paths[prev]))
+        if self.item(row):
+            self.item(row).setText(f"▶ {os.path.basename(self._paths[row])}")
         self.file_selected.emit(self._paths[row])
 
-    def _refresh_labels(self) -> None:
-        current = self.currentRow()
-        for i in range(self.count()):
-            name = os.path.basename(self._paths[i])
-            self.item(i).setText(f"▶ {name}" if i == current else name)
-
     def _on_item_clicked(self, item: QListWidgetItem) -> None:
         self._select(self.row(item))
 
@@ -666,6 +751,11 @@ class SettingsDialog(QDialog):
         self.masks_visibility_changed.emit(checked)
 
     def _on_install(self):
+        if self._worker and self._worker.isRunning():
+            return
+        if self._worker:
+            self._worker.quit()
+            self._worker.wait()
         self._btn_install.setEnabled(False)
         self._log.clear()
         self._worker = SetupWorker()
@@ -724,6 +814,8 @@ class MainWindow(QMainWindow):
         self._export_worker: ExportWorker | None = None
         self._last_export_path: str = ""
         self._mask_worker: MaskWorker | None = None
+        self._db_worker: _DBWorker | None = None
+        self._fps: float = 25.0  # cached on file load via get_fps()
 
         # Widgets
         self._playlist = PlaylistWidget()
@@ -779,6 +871,16 @@ class MainWindow(QMainWindow):
         self._cmb_portrait.setCurrentIndex(idx if idx >= 0 else 0)
         self._cmb_portrait.currentTextChanged.connect(self._on_portrait_ratio_changed)
 
+        self._cmb_format = QComboBox()
+        self._cmb_format.addItems(["MP4", "WebP sequence"])
+        saved_fmt = self._settings.value("export_format", "MP4")
+        idx = self._cmb_format.findText(saved_fmt)
+        self._cmb_format.setCurrentIndex(idx if idx >= 0 else 0)
+        self._cmb_format.currentTextChanged.connect(
+            lambda v: self._settings.setValue("export_format", v)
+        )
+        self._cmb_format.currentTextChanged.connect(self._update_next_label)
+
         self._crop_bar = CropBarWidget()
         self._crop_bar.set_crop_center(self._crop_center)
         self._crop_bar.set_portrait_ratio(
@@ -831,6 +933,8 @@ class MainWindow(QMainWindow):
         export_row.addWidget(self._txt_resize)
         export_row.addWidget(QLabel("Portrait:"))
         export_row.addWidget(self._cmb_portrait)
+        export_row.addWidget(QLabel("Format:"))
+        export_row.addWidget(self._cmb_format)
         export_row.addWidget(self._lbl_next)
         export_row.addWidget(self._btn_export)
 
@@ -849,7 +953,7 @@ class MainWindow(QMainWindow):
         mask_row.addWidget(self._cmb_mask)
         mask_row.addWidget(self._btn_masks)
         mask_row.addStretch()
-        show_masks = QSettings("8cut", "8cut").value("show_masks_row", "true") == "true"
+        show_masks = self._settings.value("show_masks_row", "true") == "true"
         self._mask_row_widget.setVisible(show_masks)
 
         right_layout.addLayout(controls)
@@ -892,18 +996,36 @@ class MainWindow(QMainWindow):
         self._btn_play.setEnabled(True)
         self._btn_pause.setEnabled(True)
         self._btn_export.setEnabled(True)
+        self._fps = self._mpv.get_fps()
+        self._crop_bar.set_source_ratio(*self._mpv.get_video_size())
 
-        match = self._db.find_similar(os.path.basename(self._file_path))
+        # Run DB fuzzy match off the main thread — can be slow on large databases.
+        filename = os.path.basename(self._file_path)
+        self._db_worker = _DBWorker(self._db, filename)
+        self._db_worker.result.connect(self._on_db_result)
+        self._db_worker.start()
+
+    def _on_db_result(self, queried: str, match: object, markers: list) -> None:
+        # Discard stale results if the user loaded a different file already.
+        if os.path.basename(self._file_path) != queried:
+            return
         if match:
             self.statusBar().showMessage(f"⚠ Similar to already processed: {match}")
         else:
             self.statusBar().clearMessage()
-
+        self._timeline.set_markers(markers)
-        self._crop_bar.set_source_ratio(*self._mpv.get_video_size())
-        self._refresh_markers()
 
     def _refresh_markers(self) -> None:
-        markers = self._db.get_markers(os.path.basename(self._file_path))
+        filename = os.path.basename(self._file_path)
+        # After an export we already know the exact stored filename, so skip
+        # the expensive fuzzy match and query directly.
+        if self._db._enabled:
+            markers = self._db._get_markers_for(filename)
+            if not markers:
+                # First export for this file — fall back to fuzzy match once.
+                markers = self._db.get_markers(filename)
+        else:
+            markers = []
         self._timeline.set_markers(markers)
 
     def _on_portrait_ratio_changed(self, text: str) -> None:
@@ -936,6 +1058,57 @@ class MainWindow(QMainWindow):
         self._mpv.stop_loop()
         self._mpv.seek(self._cursor)
 
+    def _step_cursor(self, delta: float) -> None:
+        if not self._file_path:
+            return
+        dur = self._mpv.get_duration()
+        new_t = max(0.0, min(self._cursor + delta, max(0.0, dur - 8.0)))
+        # Update label and internal state immediately; route the seek through
+        # the timeline's debounce timer so rapid key repeats don't hammer mpv.
+        self._cursor = new_t
+        self._lbl_cursor.setText(f"cursor: {format_time(new_t)}")
+        self._timeline.set_cursor(new_t)
+        self._timeline._seek_timer.start()
+
+    def _jump_to_next_marker(self) -> None:
+        markers = sorted(self._timeline._markers, key=lambda m: m[0])
+        if not markers:
+            return
+        for (t, _num, _path) in markers:
+            if t > self._cursor + 0.1:
+                self._step_cursor(t - self._cursor)
+                return
+        self._step_cursor(markers[0][0] - self._cursor)  # wrap to first
+
+    def keyPressEvent(self, event: QKeyEvent) -> None:
+        focused = QApplication.focusWidget()
+        if isinstance(focused, (QLineEdit, QPlainTextEdit)):
+            super().keyPressEvent(event)
+            return
+
+        key = event.key()
+        shift = bool(event.modifiers() & Qt.KeyboardModifier.ShiftModifier)
+        frame = 1.0 / self._fps
+        step = 1.0 if shift else frame
+
+        if key in (Qt.Key.Key_Left, Qt.Key.Key_J):
+            self._step_cursor(-step)
+        elif key in (Qt.Key.Key_Right, Qt.Key.Key_L):
+            self._step_cursor(step)
+        elif key in (Qt.Key.Key_Space, Qt.Key.Key_P):
+            if self._mpv.is_playing():
+                self._on_pause()
+            else:
+                self._on_play()
+        elif key == Qt.Key.Key_K:
+            self._on_pause()
+        elif key == Qt.Key.Key_E:
+            self._on_export()
+        elif key == Qt.Key.Key_M:
+            self._jump_to_next_marker()
+        else:
+            super().keyPressEvent(event)
+
     # --- Export ---
 
     def _pick_folder(self):
@@ -950,11 +1123,12 @@ class MainWindow(QMainWindow):
         self._update_next_label()
 
     def _update_next_label(self):
-        path = build_export_path(
+        folder = self._txt_folder.text()
-            self._txt_folder.text(),
+        name = self._txt_name.text() or "clip"
-            self._txt_name.text() or "clip",
+        if self._cmb_format.currentText() == "WebP sequence":
-            self._export_counter,
+            path = build_sequence_dir(folder, name, self._export_counter)
-        )
+        else:
+            path = build_export_path(folder, name, self._export_counter)
         self._lbl_next.setText(f"→ {os.path.basename(path)}")
 
     def _on_export(self):
@@ -964,11 +1138,14 @@ class MainWindow(QMainWindow):
             self.statusBar().showMessage("Export already running…")
             return
 
-        output = build_export_path(
+        fmt = self._cmb_format.currentText()
-            self._txt_folder.text(),
+        image_sequence = fmt == "WebP sequence"
-            self._txt_name.text() or "clip",
+        folder = self._txt_folder.text()
-            self._export_counter,
+        name = self._txt_name.text() or "clip"
-        )
+        if image_sequence:
+            output = build_sequence_dir(folder, name, self._export_counter)
+        else:
+            output = build_export_path(folder, name, self._export_counter)
 
         raw = self._txt_resize.text().strip()
         try:
@@ -989,6 +1166,7 @@ class MainWindow(QMainWindow):
             short_side=short_side,
             portrait_ratio=portrait_ratio,
             crop_center=self._crop_center,
+            image_sequence=image_sequence,
         )
         self._export_worker.finished.connect(self._on_export_done)
         self._export_worker.error.connect(self._on_export_error)
@@ -996,6 +1174,8 @@ class MainWindow(QMainWindow):
 
     def _on_export_done(self, path: str):
         self._db.add(os.path.basename(self._file_path), self._cursor, path)
+        # For MP4 exports path is a file; for WebP sequence it is a directory.
+        # build_mask_output_dir handles both correctly via Path.stem.
         self._last_export_path = path
         self._export_counter += 1
         self._update_next_label()
@@ -1020,6 +1200,9 @@ class MainWindow(QMainWindow):
         if not self._last_export_path:
             self.statusBar().showMessage("No clip exported yet — export first.")
             return
+        if os.path.isdir(self._last_export_path):
+            self.statusBar().showMessage("Mask generation requires an MP4 export — switch format to MP4 and export first.")
+            return
         if self._mask_worker and self._mask_worker.isRunning():
             self.statusBar().showMessage("Mask generation already running…")
             return

tests/test_utils.py

@@ -1,5 +1,5 @@
 import tempfile, os
-from main import build_export_path, format_time, build_ffmpeg_command, build_mask_output_dir, build_sequence_dir
+from main import build_export_path, format_time, build_ffmpeg_command, build_mask_output_dir, build_sequence_dir, build_audio_extract_command
 from main import _normalize_filename, ProcessedDB
 
 
@@ -184,6 +184,29 @@ def test_mask_output_dir_nested():
     assert build_mask_output_dir("/a/b/c/shot_042.mp4") == "/a/b/c/shot_042_masks"
 
 
+# --- build_audio_extract_command ---
+
+def test_audio_extract_output_path():
+    cmd = build_audio_extract_command("/in/v.mp4", 0.0, "/out/clip_001")
+    assert cmd[-1] == "/out/clip_001.wav"
+
+def test_audio_extract_no_video():
+    cmd = build_audio_extract_command("/in/v.mp4", 0.0, "/out/clip_001")
+    assert "-vn" in cmd
+
+def test_audio_extract_lossless_codec():
+    cmd = build_audio_extract_command("/in/v.mp4", 0.0, "/out/clip_001")
+    assert "-c:a" in cmd
+    assert cmd[cmd.index("-c:a") + 1] == "pcm_s16le"
+
+def test_audio_extract_timing():
+    cmd = build_audio_extract_command("/in/v.mp4", 12.5, "/out/clip_001")
+    assert "-ss" in cmd
+    assert cmd[cmd.index("-ss") + 1] == "12.5"
+    assert "-t" in cmd
+    assert cmd[cmd.index("-t") + 1] == "8"
+
+
 def test_build_sequence_dir_basic():
     assert build_sequence_dir("/out", "clip", 1) == "/out/clip_001"