kindly check this script and fix it as per it's potential tasks. guess my task from this script and make the script accordingly. here is the script=# @title Crop videos of folder by marking all videos
# Install necessary packages
!pip install opencv-python-headless ffmpeg-python -q

import os
import cv2
import ffmpeg
from google.colab import drive
import ipywidgets as widgets
from IPython.display import display, clear_output
import matplotlib.pyplot as plt

# Mount Google Drive
drive.mount('/content/drive')

# Function to browse directories in Google Drive
def browse_subfolders(base_folder='/content/drive/My Drive'):
    """Returns a list of subfolder paths."""
    folder_list = [base_folder]
    for dirname, _, _ in os.walk(base_folder):
        folder_list.append(dirname)
    return folder_list

# Dropdown for folder selection
drive_folder = '/content/drive/My Drive'
folder_dropdown = widgets.Dropdown(
    options=browse_subfolders(drive_folder),
    description='Select Folder:',
    layout=widgets.Layout(width='100%')
)
display(folder_dropdown)

files_list = []
current_file_index = 0
crop_settings = {}

x_start_slider = widgets.IntSlider(value=0, min=0, max=100, layout=widgets.Layout(width='50%'), description="Start X (%)")
y_start_slider = widgets.IntSlider(value=0, min=0, max=100, layout=widgets.Layout(width='50%'), description="Start Y (%)")
x_end_slider = widgets.IntSlider(value=100, min=0, max=100, layout=widgets.Layout(width='50%'), description="End X (%)")
y_end_slider = widgets.IntSlider(value=100, min=0, max=100, layout=widgets.Layout(width='50%'), description="End Y (%)")

image_widget = widgets.Output()

def set_slider_max_values(video_path):
    cap = cv2.VideoCapture(video_path)
    ret, frame = cap.read()
    cap.release()

    if not ret:
        print("Error reading video frame.")
        return None, None  # Return None to indicate failure

    height, width = frame.shape[:2]
    return width, height

def update_folder_path(change):
    global drive_folder, files_list, crop_settings
    drive_folder = change.new
    print(f'Selected folder: {drive_folder}')
    files_list = [os.path.join(drive_folder, f) for f in os.listdir(drive_folder) if f.lower().endswith(('.mp4', '.avi', '.mov', '.mkv'))]
    if not files_list:
        print("No video files found in the selected folder.")
        return
    else:
        print(f"Found {len(files_list)} video files.")

    current_file_index = 0
    crop_settings = {file: (0, 0, 100, 100) for file in files_list}
    update_sliders_for_current_file()
    show_preview()

folder_dropdown.observe(update_folder_path, names='value')

def update_sliders_for_current_file():
    if files_list:  # Check if the list is not empty
        current_file = files_list[current_file_index]
        start_x, start_y, end_x, end_y = crop_settings[current_file]
        x_start_slider.value = start_x
        y_start_slider.value = start_y
        x_end_slider.value = end_x
        y_end_slider.value = end_y
    else:
        print("No video files available to set sliders.")

def show_preview(*args):
    clear_output(wait=True)
    if not files_list:
        print("No video files available to preview.")
        return

    display(folder_dropdown, x_start_slider, y_start_slider, x_end_slider, y_end_slider, set_button, next_button, crop_all_button)

    current_file = files_list[current_file_index]
    
    cap = cv2.VideoCapture(current_file)
    ret, frame = cap.read()
    cap.release()

    if not ret:
        print(f"Error reading video: {current_file}")
        return

    width, height = frame.shape[1], frame.shape[0]
    frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
    fig, ax = plt.subplots(figsize=(4, 3))
    ax.imshow(frame_rgb)
    ax.set_title(f'Crop area for: {os.path.basename(current_file)}')
    start_x = int(x_start_slider.value / 100 * width)
    start_y = int(y_start_slider.value / 100 * height)
    end_x = int(x_end_slider.value / 100 * width)
    end_y = int(y_end_slider.value / 100 * height)
    crop_area = [(start_x, start_y), (end_x, end_y)]
    rect = plt.Rectangle(crop_area[0], crop_area[1][0] - crop_area[0][0], crop_area[1][1] - crop_area[0][1],
                         linewidth=1, edgecolor='r', facecolor='none')
    ax.add_patch(rect)
    plt.show()

def set_crop_for_current_file():
    if files_list:  # Check if there are videos to set
        current_file = files_list[current_file_index]
        crop_settings[current_file] = (x_start_slider.value, y_start_slider.value, x_end_slider.value, y_end_slider.value)
        print(f"Set crop for {os.path.basename(current_file)}: {crop_settings[current_file]}")

def next_video(*args):
    global current_file_index
    if current_file_index < len(files_list) - 1:
        current_file_index += 1
        update_sliders_for_current_file()
        show_preview()

def crop_videos():
    if not files_list:
        print("No videos to crop.")
        return

    print("Starting crop...")
    for input_file in files_list:
        file_dir, file_name = os.path.split(input_file)
        file_base, file_ext = os.path.splitext(file_name)
        output_file = os.path.join(file_dir, f"{file_base}_cropped{file_ext}")

        crop_info = crop_settings[input_file]
        start_x_percent, start_y_percent, end_x_percent, end_y_percent = crop_info

        width, height = set_slider_max_values(input_file)
        
        if width is None or height is None:
            print(f"Skipping {input_file} due to read error.")
            continue
        
        start_x = int(start_x_percent / 100 * width)
        start_y = int(start_y_percent / 100 * height)
        end_x = int(end_x_percent / 100 * width)
        end_y = int(end_y_percent / 100 * height)

        crop_width = end_x - start_x
        crop_height = end_y - start_y

        if crop_width <= 0 or crop_height <= 0:
            print(f"Invalid crop dimensions for {input_file}")
            continue

        try:
            streams = ffmpeg.input(input_file)
            video_stream = streams.video.filter('crop', x=start_x, y=start_y, out_w=crop_width, out_h=crop_height)
            (
                ffmpeg
                .output(video_stream, streams.audio, output_file, vcodec='libx264', acodec='aac', audio_bitrate='192k')
                .run(overwrite_output=True)
            )
            print(f"Cropped and saved as: {output_file}")
        except ffmpeg.Error as e:
            print("File conversion failed")
            print(e.stdout.decode('utf8'))
            print(e.stderr.decode('utf8'))
        except Exception as e:
            print(f"Unexpected error: {str(e)}")

set_button = widgets.Button(description="Set Crop for Current Video")
set_button.on_click(lambda b: set_crop_for_current_file())

next_button = widgets.Button(description="Next Video")
next_button.on_click(lambda b: next_video())

crop_all_button = widgets.Button(description="Start Cropping All Videos")
crop_all_button.on_click(lambda b: crop_videos())

# Automatically update the preview when sliders are adjusted
x_start_slider.observe(show_preview, names='value')
y_start_slider.observe(show_preview, names='value')
x_end_slider.observe(show_preview, names='value')
y_end_slider.observe(show_preview, names='value')