Add clap/onset auto-detection feature

Ports scripts/detect_claps.py (a librosa-based onset detector from an earlier session) into clap_detection.py, shared by both the CLI script and a new GUI feature: 'Detect All Claps' (whole-file scan) and 'Detect Next Clap' (from cursor, first result only), with results shown as clickable markers on a new MarkerStrip widget above the seek slider -- clicking one seeks the player to that exact timestamp. Caught a real correctness bug while testing against the out-of-sync fixture (not just the plain in-sync one): ffmpeg's default -vn audio extraction silently drops the audio stream's own start_time and renormalizes to t=0 -- which is exactly the offset this whole tool exists to fix, so losing it meant detected timestamps pointed at the wrong track's timing entirely. Fixed by probing the true start_time via ffprobe and re-inserting it as explicit silence (adelay) before analysis. Also dropped an earlier attempt at an ffmpeg -ss seek optimization for the from-cursor case, since combining it with the start_time fix meant two independent timestamp-origin corrections stacked on each other -- correct in theory, too easy to get subtly wrong in a tool where a silent wrong-timestamp bug is the worst possible failure mode. Full-file decode + filter in Python is slower but unambiguous. Verified with a smoke test that drives the real MainWindow buttons, confirms the detected marker lands near the fixture's known beep (t=5.350s, allowing for onset-detection lag), and simulates an actual QMouseEvent click on the marker to confirm click-to-seek works end-to-end.
2026-07-26 01:46:11 +02:00
parent f6e6f79a34
commit f7c15e924c
6 changed files with 468 additions and 1 deletions
@@ -0,0 +1,68 @@
+from typing import List
+
+from PyQt6.QtCore import Qt, QPointF, pyqtSignal
+from PyQt6.QtGui import QPainter, QColor, QPolygonF
+from PyQt6.QtWidgets import QWidget
+
+MARKER_COLOR = QColor(230, 126, 34)  # orange
+CLICK_TOLERANCE_PX = 8.0
+
+
+class MarkerStrip(QWidget):
+    """Thin strip drawn directly above the seek slider (same width, via a
+    shared parent layout) showing detected clap/onset markers as small
+    triangles. Clicking one seeks the player to that exact timestamp.
+    """
+
+    markerClicked = pyqtSignal(float)
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setFixedHeight(14)
+        self.setCursor(Qt.CursorShape.PointingHandCursor)
+        self._duration = 0.0
+        self._markers: List[float] = []
+
+    def set_duration(self, duration: float):
+        self._duration = duration
+        self.update()
+
+    def set_markers(self, markers: List[float]):
+        self._markers = sorted(markers)
+        self.update()
+
+    def markers(self) -> List[float]:
+        return list(self._markers)
+
+    def clear(self):
+        self._markers = []
+        self.update()
+
+    def _x_for_time(self, t: float) -> float:
+        if self._duration <= 0:
+            return 0.0
+        return (t / self._duration) * self.width()
+
+    def paintEvent(self, event):
+        if not self._markers or self._duration <= 0:
+            return
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.RenderHint.Antialiasing)
+        painter.setPen(Qt.PenStyle.NoPen)
+        painter.setBrush(MARKER_COLOR)
+        for t in self._markers:
+            x = self._x_for_time(t)
+            triangle = QPolygonF([
+                QPointF(x - 5, 0),
+                QPointF(x + 5, 0),
+                QPointF(x, 10),
+            ])
+            painter.drawPolygon(triangle)
+
+    def mousePressEvent(self, event):
+        if not self._markers or self._duration <= 0:
+            return
+        click_x = event.position().x()
+        closest = min(self._markers, key=lambda t: abs(self._x_for_time(t) - click_x))
+        if abs(self._x_for_time(closest) - click_x) <= CLICK_TOLERANCE_PX:
+            self.markerClicked.emit(closest)