fix check video type cv2.VideoCapture and add unittest

Link: https://code.alibaba-inc.com/Ali-MaaS/MaaS-lib/codereview/11181951

modelscope/pipeline_inputs.py

@@ -38,10 +38,10 @@ INPUT_TYPE = {
 
 def check_input_type(input_type, input):
     expected_type = INPUT_TYPE[input_type]
-    if expected_type == 'cv2.VideoCapture':
+    if input_type == InputType.VIDEO:
         # special type checking using class name, to avoid introduction of opencv dependency into fundamental framework.
-        assert type(input).__name__ == 'VideoCapture',\
-            f'invalid input type for {input_type}, expected cv2.VideoCapture but got {type(input)}\n {input}'
+        assert type(input).__name__ == 'VideoCapture' or isinstance(input, expected_type),\
+            f'invalid input type for {input_type}, expected {expected_type} but got {type(input)}\n {input}'
     else:
         assert isinstance(input, expected_type), \
             f'invalid input type for {input_type}, expected {expected_type} but got {type(input)}\n {input}'

tests/pipelines/test_body_3d_keypoints.py

@@ -39,9 +39,7 @@ class Body3DKeypointsTest(unittest.TestCase, DemoCompatibilityCheck):
         if not cap.isOpened():
             raise Exception('modelscope error: %s cannot be decoded by OpenCV.'
                             % (self.test_video))
-        pipeline_input = self.test_video
-        self.pipeline_inference(
-            body_3d_keypoints, pipeline_input=pipeline_input)
+        self.pipeline_inference(body_3d_keypoints, pipeline_input=cap)
 
     @unittest.skipUnless(test_level() >= 0, 'skip test in current test level')
     def test_demo_compatibility(self):