Removing `no_webcam.py` and relying on default error image for the CI

examples/python-dataflow/dataflow_without_webcam.yml

@@ -1,25 +0,0 @@
-nodes:
-  - id: no_webcam
-    custom:
-      source: ./no_webcam.py
-      inputs:
-        tick:
-          source: dora/timer/millis/100
-          queue_size: 100
-      outputs:
-        - image
-
-  - id: object_detection
-    custom:
-      source: ./object_detection.py
-      inputs:
-        image: no_webcam/image
-      outputs:
-        - bbox
-
-  - id: plot
-    custom:
-      source: ./plot.py
-      inputs:
-        image: no_webcam/image
-        bbox: object_detection/bbox

examples/python-dataflow/no_webcam.py

@@ -1,28 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-
-import time
-import urllib.request
-
-import cv2
-import numpy as np
-from dora import Node
-
-req = urllib.request.urlopen("https://ultralytics.com/images/zidane.jpg")
-
-arr = np.asarray(bytearray(req.read()), dtype=np.uint8)
-node = Node()
-
-start = time.time()
-
-while time.time() - start < 20:
-    # Wait next dora_input
-    event = node.next()
-    match event["type"]:
-        case "INPUT":
-            print("received input", event["id"])
-            node.send_output("image", arr.tobytes())
-        case "STOP":
-            print("received stop")
-        case other:
-            print("received unexpected event:", other)

examples/python-dataflow/webcam.py

@@ -1,15 +1,20 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+import os
 import time
-
+import numpy as np
 import cv2
 
 from dora import Node
 
 node = Node()
 
-video_capture = cv2.VideoCapture(0)
+CAMERA_INDEX = int(os.getenv("CAMERA_INDEX", 0))
+CAMERA_WIDTH = 640
+CAMERA_HEIGHT = 480
+video_capture = cv2.VideoCapture(CAMERA_INDEX)
+font = cv2.FONT_HERSHEY_SIMPLEX
 
 start = time.time()
 
@@ -20,12 +25,23 @@ while time.time() - start < 10:
     match event["type"]:
         case "INPUT":
             ret, frame = video_capture.read()
-            if ret:
-                node.send_output(
-                    "image",
-                    cv2.imencode(".jpg", frame)[1].tobytes(),
-                    event["metadata"],
+            if not ret:
+                frame = np.zeros((CAMERA_HEIGHT, CAMERA_WIDTH, 3), dtype=np.uint8)
+                cv2.putText(
+                    frame,
+                    "No Webcam was found at index %d" % (CAMERA_INDEX),
+                    (int(30), int(30)),
+                    font,
+                    0.75,
+                    (255, 255, 255),
+                    2,
+                    1,
                 )
+            node.send_output(
+                "image",
+                cv2.imencode(".jpg", frame)[1].tobytes(),
+                event["metadata"],
+            )
         case "STOP":
             print("received stop")
             break

examples/python-operator-dataflow/dataflow_without_webcam.yml

@@ -1,23 +0,0 @@
-nodes:
-  - id: no_webcam
-    custom:
-      source: ./no_webcam.py
-      inputs:
-        tick: dora/timer/millis/100
-      outputs:
-        - image
-
-  - id: object_detection
-    operator:
-      python: object_detection.py
-      inputs:
-        image: no_webcam/image
-      outputs:
-        - bbox
-
-  - id: plot
-    operator:
-      python: plot.py
-      inputs:
-        image: no_webcam/image
-        bbox: object_detection/bbox

examples/python-operator-dataflow/no_webcam.py

@@ -1,43 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-
-import time
-import urllib.request
-
-import cv2
-import numpy as np
-import pyarrow as pa
-
-from dora import Node
-
-print("Hello from no_webcam.py")
-
-
-CAMERA_WIDTH = 640
-CAMERA_HEIGHT = 480
-
-# Preprocessing the image
-req = urllib.request.urlopen(
-    "https://img0.baidu.com/it/u=2940037857,1417768899&fm=253&fmt=auto&app=138&f=PNG?w=724&h=500"
-)  # This image works in china better
-arr = np.asarray(bytearray(req.read()), dtype=np.uint8)
-image = cv2.imdecode(arr, -1)[:, :, :3]
-image = cv2.resize(image, (CAMERA_WIDTH, CAMERA_HEIGHT))
-
-# Numpy -> Arrow
-image = pa.array(image.flatten().view(np.uint8))
-node = Node()
-
-start = time.time()
-
-while time.time() - start < 20:
-    # Wait next dora_input
-    event = node.next()
-    match event["type"]:
-        case "INPUT":
-            print("received input", event["id"])
-            node.send_output("image", image)
-        case "STOP":
-            print("received stop")
-        case other:
-            print("received unexpected event:", other)

examples/python-operator-dataflow/webcam.py

@@ -13,7 +13,7 @@ from dora import DoraStatus
 
 CAMERA_WIDTH = 640
 CAMERA_HEIGHT = 480
-CAMERA_INDEX = os.getenv("CAMERA_INDEX", 0)
+CAMERA_INDEX = int(os.getenv("CAMERA_INDEX", 0))
 
 font = cv2.FONT_HERSHEY_SIMPLEX