Make video preview

video.py

# Creates previews for videos - random short snippets of 2 seconds each
# pip install moviepy==1.0.3
# use python video.py <input_video_path> <output_video_name> <duration_in_seconds>

from moviepy.video.compositing.concatenate import concatenate_videoclips
from moviepy.editor import VideoFileClip
import sys
import random
import argparse


def create_preview(input_video: str, output_video: str, duration: float) -> None:
    """
    Create a preview video from the input video with the specified duration and save it to the output video file.

    Args:
    input_video (str): The path to the input video file.
    output_video (str): The path to save the output preview video file.
    duration (float): The duration of the preview video in seconds.
    """
    video = VideoFileClip(input_video)
    total_duration = video.duration
    clips = []
    current_duration = 0

    while current_duration < duration:
        start_time = random.uniform(0, total_duration - 2)
        clip = video.subclip(start_time, start_time + 2)
        if current_duration + clip.duration > duration:
            clip = clip.subclip(0, duration - current_duration)
        clips.append((start_time, clip))
        current_duration += clip.duration

    clips.sort(key=lambda clip: clip[0])
    clips = [clip[1] for clip in clips]
    preview = concatenate_videoclips(clips)
    preview.write_videofile(output_video)


def parse_args(args: list[str]) -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        prog="preview", description="Makes short preview from video"
    )
    parser.add_argument("input_video_path", type=str)
    parser.add_argument("output_video_name", type=str, nargs="?")
    parser.add_argument("duration", type=float, nargs="?", default=20.0)

    return parser.parse_args(args)


def main():
    args = parse_args(sys.argv[1:])
    if not args.output_video_name:
        output_name = args.input_video_path.rsplit(".", 1)[0]
        args.output_video_name = f"{output_name}_preview.mp4"

    create_preview(args.input_video_path, args.output_video_name, args.duration)


if __name__ == "__main__":
    main()