68 lines
1.7 KiB
Python
68 lines
1.7 KiB
Python
import abc
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from pathlib import Path
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import cv2
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def create_video_writer(video_cap: cv2.VideoCapture, output_filename: Path) -> cv2.VideoWriter:
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# grab the width, height, and fps of the frames in the video stream.
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frame_width = int(video_cap.get(cv2.CAP_PROP_FRAME_WIDTH))
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frame_height = int(video_cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
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fps = int(video_cap.get(cv2.CAP_PROP_FPS))
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# initialize the FourCC and a video writer object
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fourcc = cv2.VideoWriter_fourcc(*'mp4v')
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writer = cv2.VideoWriter(str(output_filename.absolute()),
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fourcc,
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fps,
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(frame_width, frame_height))
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return writer
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class VideoWriter(abc.ABC):
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@abc.abstractmethod
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def write_frame(self, frame) -> None:
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pass
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@abc.abstractmethod
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def close(self) -> None:
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pass
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class NoopVideoWriter(VideoWriter):
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def write_frame(self, frame) -> None:
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pass
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def close(self) -> None:
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pass
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class MP4VVideoWriter(VideoWriter):
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def __init__(self, video_writer: cv2.VideoWriter) -> None:
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self._video_writer = video_writer
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def write_frame(self, frame) -> None:
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self._video_writer.write(frame)
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def close(self) -> None:
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self._video_writer.release()
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cv2.destroyAllWindows()
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@classmethod
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def from_frame(cls, input_: Path, output: Path) -> VideoWriter:
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video_cap = cv2.VideoCapture(str(input_))
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try:
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return cls(create_video_writer(video_cap, output))
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finally:
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video_cap.release()
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class MP4VVideoWriterWithFrame(MP4VVideoWriter):
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def write_frame(self, frame) -> None:
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super().write_frame(frame)
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cv2.imshow("Frame", frame)
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