crop_video.py

import cv2
import numpy as np
import argparse
from pathlib import Path

"""
Script for syncing two videos in time and making these equally long.
Provide the paths to the videos and the name of the output video as arguments.

Press "1" to move forward in the first video, "2" for the second video, and enter to
initiate saving.
"""


def main(args):
    """Loads two videos and generates an interface to crop these to equal length and syncing in time.

    Args:
        args (dict): _description_
    """

    path1 = Path.joinpath(
        Path(__file__).parents[0].resolve(), "videos_original/" + args.path_1
    )
    path2 = Path.joinpath(
        Path(__file__).parents[0].resolve(), "videos_original/" + args.path_2
    )
    vidname = args.name_out

    cap1 = cv2.VideoCapture(str(path1))
    nbr_frames1 = int(cap1.get(cv2.CAP_PROP_FRAME_COUNT)) - 1
    cap2 = cv2.VideoCapture(str(path2))
    nbr_frames2 = int(cap2.get(cv2.CAP_PROP_FRAME_COUNT)) - 1

    _, f1 = cap1.read()
    _, f2 = cap2.read()
    height, width, _ = f1.shape

    # Find a starting point
    while True:
        f = np.hstack((f1, f2))
        f = cv2.resize(f, (0, 0), fx=0.5, fy=0.5)
        cv2.imshow("", f)
        k = cv2.waitKey(0) & 0xFF
        if k == 49:  # 1 is pressed
            _, f1 = cap1.read()
            nbr_frames1 -= 1
        elif k == 50:  # 2 is pressed
            _, f2 = cap2.read()
            nbr_frames2 -= 1
        else:
            break

    # Create and save two equally long clips
    clip1 = cv2.VideoWriter(
        str(
            Path.joinpath(
                Path(__file__).parents[0].resolve(), "videos/" + vidname + "_1.mp4"
            )
        ),
        cv2.VideoWriter_fourcc(*"mp4v"),
        30.0,
        (width, height),
    )
    clip2 = cv2.VideoWriter(
        str(
            Path.joinpath(
                Path(__file__).parents[0].resolve(), "videos/" + vidname + "_2.mp4"
            )
        ),
        cv2.VideoWriter_fourcc(*"mp4v"),
        30.0,
        (width, height),
    )

    for _ in range(min([nbr_frames1, nbr_frames2])):
        _, f1 = cap1.read()
        _, f2 = cap2.read()
        clip1.write(f1)
        clip2.write(f2)
    clip1.release()
    clip2.release()
    cap1.release()
    cap2.release()
    cv2.destroyAllWindows()


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--path_1",
        type=str,
        required=True,
        help="path to the first video relative to root/videos_original.",
    )
    parser.add_argument(
        "--path_2",
        type=str,
        required=True,
        help="path to the second video relative to this root/videos_original.",
    )
    parser.add_argument(
        "--name_out",
        type=str,
        required=True,
        help="name of the output videos. These will be stored in videos/name_out_1.mp4 and videos/name_out_2.mp4",
    )

    args = parser.parse_args()
    main(args)