its the issue with opencv_videoio_ffmpeg<version>.dll file.
i just copied opencv_videoio_ffmpeg454_64.dll (belongs to opencv-python==4.5.4.60) and replaced that with my version (opencv_videoio_ffmpeg4110_64.dll) and renamed it to opencv_videoio_ffmpeg454_64.dll.
my issue got resolved.

you can find this dll file inside the Lib/site-packages/cv2