webcam: back to opencv (#35522)

* Revert "webcam: remove other cv2 usage (#33236)"

This reverts commit 0cade54015.

* Revert "remove cv2 usage (#33101)"

This reverts commit 144e9e271c.

* Revert "remove opencv-python-headless (#33082)"

This reverts commit 488e08507a.

* update uv.lock

* keep av bgr2nv12

* rename

pyproject.toml

@@ -107,6 +107,7 @@ dev = [
   "dbus-next",
   "dictdiffer",
   "matplotlib",
+  "opencv-python-headless",
   "parameterized >=0.8, <0.9",
   "pyautogui",
   "pygame",

tools/webcam/camera.py

@@ -1,4 +1,5 @@
 import av
+import cv2 as cv
 
 class Camera:
   def __init__(self, cam_type_state, stream_type, camera_id):
@@ -10,11 +11,9 @@ class Camera:
     self.stream_type = stream_type
     self.cur_frame_id = 0
 
-    self.container = av.open(camera_id)
-    assert self.container.streams.video, f"Can't open video stream for camera {camera_id}"
-    self.video_stream = self.container.streams.video[0]
-    self.W = self.video_stream.codec_context.width
-    self.H = self.video_stream.codec_context.height
+    self.cap = cv.VideoCapture(camera_id)
+    self.W = self.cap.get(cv.CAP_PROP_FRAME_WIDTH)
+    self.H = self.cap.get(cv.CAP_PROP_FRAME_HEIGHT)
 
   @classmethod
   def bgr2nv12(self, bgr):
@@ -22,8 +21,10 @@ class Camera:
     return frame.reformat(format='nv12').to_ndarray()
 
   def read_frames(self):
-    for frame in self.container.decode(self.video_stream):
-      img = frame.to_rgb().to_ndarray()[:,:, ::-1] # convert to bgr24
-      yuv = Camera.bgr2nv12(img)
+    while True:
+      ret, frame = self.cap.read()
+      if not ret:
+        break
+      yuv = Camera.bgr2nv12(frame)
       yield yuv.data.tobytes()
-    self.container.close()
+    self.cap.release()

uv.lock

@@ -1280,6 +1280,7 @@ dev = [
     { name = "dbus-next" },
     { name = "dictdiffer" },
     { name = "matplotlib" },
+    { name = "opencv-python-headless" },
     { name = "parameterized" },
     { name = "pyautogui" },
     { name = "pygame" },
@@ -1349,6 +1350,7 @@ requires-dist = [
     { name = "natsort", marker = "extra == 'docs'" },
     { name = "numpy", specifier = ">=2.0,<2.2" },
     { name = "onnx", specifier = ">=1.14.0" },
+    { name = "opencv-python-headless", marker = "extra == 'dev'" },
     { name = "parameterized", marker = "extra == 'dev'", specifier = ">=0.8,<0.9" },
     { name = "pre-commit-hooks", marker = "extra == 'testing'" },
     { name = "psutil" },