Add causal person fusion and MuVAP stage-3 baselines

third_party/MuVAP/preprocess/asd/video.py

@@ -0,0 +1,84 @@
+"""Reading face crops off a source video.
+
+Shared by the dataset adapters that pack from video rather than from
+pre-extracted frames.
+"""
+
+import cv2
+import numpy as np
+
+
+def crop_face(frame, bbox, gray=True, dim=(112, 112)):
+    if bbox is None:
+        return np.full(dim if gray else (dim[1], dim[0], 3), 128, dtype=np.uint8)
+
+    x1, y1, x2, y2 = int(bbox[0]), int(bbox[1]), int(bbox[2]), int(bbox[3])
+
+    if x1 >= x2 or y1 >= y2:
+        return np.full(dim if gray else (dim[1], dim[0], 3), 128, dtype=np.uint8)
+
+    h, w = frame.shape[:2]
+    cx, cy = (x1 + x2) // 2, (y1 + y2) // 2
+    size = max(x2 - x1, y2 - y1)
+    half = size // 2
+
+    x1s, y1s = cx - half, cy - half
+    x2s, y2s = x1s + size, y1s + size
+
+    x1c, y1c = max(0, x1s), max(0, y1s)
+    x2c, y2c = min(w, x2s), min(h, y2s)
+
+    if x1c >= x2c or y1c >= y2c:
+        return np.full(dim if gray else (dim[1], dim[0], 3), 128, dtype=np.uint8)
+
+    cropped = frame[y1c:y2c, x1c:x2c]
+
+    if gray:
+        cropped = cv2.cvtColor(cropped, cv2.COLOR_BGR2GRAY)
+        border_val = 128
+    else:
+        cropped = cv2.cvtColor(cropped, cv2.COLOR_BGR2RGB)
+        border_val = (128, 128, 128)
+
+    pad_top, pad_left = y1c - y1s, x1c - x1s
+    pad_bottom, pad_right = y2s - y2c, x2s - x2c
+
+    if pad_top > 0 or pad_bottom > 0 or pad_left > 0 or pad_right > 0:
+        cropped = cv2.copyMakeBorder(
+            cropped,
+            pad_top,
+            pad_bottom,
+            pad_left,
+            pad_right,
+            cv2.BORDER_CONSTANT,
+            value=border_val,
+        )
+
+    return cv2.resize(cropped, dim)
+
+
+def load_visual(video_path, start_frame=0, target_frames=None):
+    """Decode a native-FPS video interval without changing its timeline."""
+    if start_frame < 0:
+        raise ValueError("start_frame cannot be negative")
+    if target_frames is not None and target_frames < 0:
+        raise ValueError("target_frames cannot be negative")
+
+    cap = cv2.VideoCapture(str(video_path))
+    if not cap.isOpened():
+        raise FileNotFoundError(f"could not open video: {video_path}")
+
+    fps = float(cap.get(cv2.CAP_PROP_FPS))
+    if fps <= 0:
+        cap.release()
+        raise ValueError(f"video has an invalid frame rate: {video_path}")
+
+    cap.set(cv2.CAP_PROP_POS_FRAMES, start_frame)
+    frames = []
+    while target_frames is None or len(frames) < target_frames:
+        ok, frame = cap.read()
+        if not ok:
+            break
+        frames.append(frame)
+    cap.release()
+    return frames, fps