webcam: set width, height, fps; flip image; use av reformat

Author: andiradulescu

tools/webcam/camera.py

@@ -1,6 +1,5 @@
-# TODO: remove the cv2 dependency, it's only used here
+import av
 import cv2 as cv
-import numpy as np
 
 class Camera:
   def __init__(self, cam_type_state, stream_type, camera_id):
@@ -12,23 +11,29 @@ def __init__(self, cam_type_state, stream_type, camera_id):
     self.stream_type = stream_type
     self.cur_frame_id = 0
 
+    print(f"Opening {cam_type_state} at {camera_id}")
+
     self.cap = cv.VideoCapture(camera_id)
+
+    self.cap.set(cv.CAP_PROP_FRAME_WIDTH, 1920.0)
+    self.cap.set(cv.CAP_PROP_FRAME_HEIGHT, 1080.0)
+    self.cap.set(cv.CAP_PROP_FPS, 30.0)
+
     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):
-    yuv = cv.cvtColor(bgr, cv.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
+    frame = av.VideoFrame.from_ndarray(bgr, format='bgr24')
+    return frame.reformat(format='nv12').to_ndarray()
 
   def read_frames(self):
     while True:
-      sts , frame = self.cap.read()
-      if not sts:
+      ret, frame = self.cap.read()
+      if not ret:
         break
+      # Rotate the frame 180 degrees (flip both axes)
+      frame = cv.flip(frame, -1)
       yuv = Camera.bgr2nv12(frame)
       yield yuv.data.tobytes()
     self.cap.release()

tools/webcam/camerad.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3
 import threading
 import os
+import platform
 from collections import namedtuple
 
 from msgq.visionipc import VisionIpcServer, VisionStreamType
@@ -25,8 +26,7 @@ def __init__(self):
 
     self.cameras = []
     for c in CAMERAS:
-      cam_device = f"/dev/video{c.cam_id}"
-      print(f"opening {c.msg_name} at {cam_device}")
+      cam_device = f"/dev/video{c.cam_id}" if platform.system() != "Darwin" else c.cam_id
       cam = Camera(c.msg_name, c.stream_type, cam_device)
       self.cameras.append(cam)
       self.vipc_server.create_buffers(c.stream_type, 20, cam.W, cam.H)