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import cv2
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class VideoProcessing:
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"""@brief A class for loading, reading, and managing video streams using OpenCV.
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@details
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This class provides basic functionality for working with video files:
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- Loading a video from a file path.
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- Reading frames sequentially.
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- Releasing system resources after use.
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It is designed for modular integration with image-processing workflows,
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enabling real-time or frame-by-frame analysis from video inputs.
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"""
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def __init__(self, video_path=None):
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"""@brief Initialize the VideoProcessing object.
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@details
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Optionally takes a video file path at initialization. If provided,
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the constructor automatically loads the video for reading.
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@param video_path (optional) The file path to the video file to load.
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"""
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self.cap = None
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if video_path:
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self.load_video(video_path)
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def load_video(self, video_path):
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"""@brief Load a video file for processing.
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@details
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Opens a video file using OpenCV’s `VideoCapture`. If another video is
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already loaded, it is safely released before opening the new one.
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@param video_path The file path to the video file to load.
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@throws ValueError If the video cannot be opened successfully.
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"""
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if self.cap is not None:
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self.cap.release()
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self.cap = cv2.VideoCapture(video_path)
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if not self.cap.isOpened():
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raise ValueError(f"Cannot open video file: {video_path}")
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def get_next_frame(self):
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"""@brief Retrieve the next frame from the video stream.
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@details
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Reads the next available frame from the video. If the end of the video
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is reached or the video is not properly loaded, returns `None`.
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@return The next video frame as a NumPy array, or `None` if no frame is available.
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@throws RuntimeError If no video is loaded before calling this function.
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"""
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if self.cap is None:
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raise RuntimeError("No video loaded. Call load_video() first.")
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ret, frame = self.cap.read()
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if not ret:
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return None # End of video or error
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return frame
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def release(self):
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"""@brief Release the video capture resource.
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@details
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Safely releases the OpenCV `VideoCapture` object to free up system resources.
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This should always be called when video processing is complete.
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"""
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if self.cap is not None:
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self.cap.release()
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self.cap = None
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