chore: import upstream snapshot with attribution

examples/python/nv12/README.md

@@ -0,0 +1,18 @@
+<!--[metadata]
+title = "NV12"
+tags = ["2D", "Image encoding", "YUV"]
+thumbnail = "https://static.rerun.io/nv12/3bffd358462a453c6358aa3cc4c8555b12fc0d35/480w.png"
+thumbnail_dimensions = [480, 480]
+-->
+
+This example displays an NV12 encoded video stream from a webcam in rerun.
+
+<img src="https://static.rerun.io/nv12/3bffd358462a453c6358aa3cc4c8555b12fc0d35/480w.png">
+
+
+## Run the code
+
+```bash
+pip install -e examples/python/nv12
+python -m nv12
+```

examples/python/nv12/nv12.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+"""Stream NV12 images from a webcam."""
+
+from __future__ import annotations
+
+import argparse
+import time
+
+import cv2
+import numpy as np
+
+import rerun as rr  # pip install rerun-sdk
+
+
+def bgr2nv12(bgr: cv2.typing.MatLike) -> cv2.typing.MatLike:
+    yuv = cv2.cvtColor(bgr, cv2.COLOR_BGR2YUV_I420)
+    uv_row_cnt = yuv.shape[0] // 3
+    uv_plane = np.transpose(yuv[uv_row_cnt * 2 :].reshape(2, -1), [1, 0])
+    yuv[uv_row_cnt * 2 :] = uv_plane.reshape(uv_row_cnt, -1)
+    return yuv
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="Example of using the Rerun visualizer to display NV12 images.")
+    rr.script_add_args(parser)
+    parser.add_argument(
+        "-t",
+        "--timeout",
+        type=float,
+        default=5,
+        help="Timeout in seconds, after which the script will stop streaming frames.",
+    )
+    args = parser.parse_args()
+
+    rr.script_setup(args, "rerun_example_nv12")
+
+    cap = cv2.VideoCapture(0)
+    if not cap.isOpened():
+        raise RuntimeError("This example requires a webcam.")
+    start_time = time.time()
+    print(f"Started streaming NV12 images for {args.timeout} seconds.")
+    while start_time + args.timeout > time.time():
+        ret, frame = cap.read()
+        if not ret:
+            time.sleep(0.01)
+            continue
+        rr.log(
+            "NV12",
+            rr.Image(
+                bytes=bytes(bgr2nv12(frame)),
+                width=frame.shape[1],
+                height=frame.shape[0],
+                pixel_format=rr.PixelFormat.NV12,
+            ),
+        )
+        time.sleep(0.01)
+    rr.script_teardown(args)
+
+
+if __name__ == "__main__":
+    main()

examples/python/nv12/pyproject.toml

@@ -0,0 +1,12 @@
+[project]
+name = "nv12"
+version = "0.1.0"
+readme = "README.md"
+dependencies = ["rerun-sdk>=0.10", "opencv-python", "numpy"]
+
+[project.scripts]
+nv12 = "nv12:main"
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"