webcam: remove other cv2 usage (#33236)

av
old-commit-hash: a8c0c158ad

tools/webcam/camera.py

@@ -11,6 +11,7 @@ class Camera:
     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

tools/webcam/camerad.py

@@ -26,7 +26,6 @@ class Camerad:
     self.cameras = []
     for c in CAMERAS:
       cam = Camera(c.msg_name, c.stream_type, c.cam_id)
-      assert cam.cap.isOpened(), f"Can't find camera {c}"
       self.cameras.append(cam)
       self.vipc_server.create_buffers(c.stream_type, 20, False, cam.W, cam.H)
 
@@ -47,11 +46,10 @@ class Camerad:
 
   def camera_runner(self, cam):
     rk = Ratekeeper(20, None)
-    while cam.cap.isOpened():
-      for yuv in cam.read_frames():
-        self._send_yuv(yuv, cam.cur_frame_id, cam.cam_type_state, cam.stream_type)
-        cam.cur_frame_id += 1
-        rk.keep_time()
+    for yuv in cam.read_frames():
+      self._send_yuv(yuv, cam.cur_frame_id, cam.cam_type_state, cam.stream_type)
+      cam.cur_frame_id += 1
+      rk.keep_time()
 
   def run(self):
     threads = []