import argparse
import os
import subprocess
from glob import glob


def create_arg_parser():
    parser = argparse.ArgumentParser()
    parser.add_argument('--dir', type=str, default='./')
    parser.add_argument('--dryrun', type=bool, default=False)
    args = parser.parse_args()  
    return args


def extract_frame(file_path, save_dir, dryrun=False):
    basename = os.path.basename(file_path)
    basename_without_ext = os.path.splitext(basename)[0]
    cmd = r'ffmpeg -i {} -r 2 -vcodec png -filter:v "crop=w=960:h=1280:x=0:y=0" {}/{}_%04d.png'.format(
        file_path, save_dir, basename_without_ext)
    print('Execute:', cmd)
    if not dryrun:
        subprocess.run(cmd)


def main():
    """
    dir/
    ├ sample01/
    ├   ├ file01.mp4
    ├   └ file02.mp4
    ├ sample02/
    └ sample03/
    """
    args = create_arg_parser()
    dir_list = glob(os.path.join(args.dir, '*'))
    if len(dir_list) == 0:
        raise ValueError('No directories')
    
    for i_dir in dir_list:
        mov_file_list = glob(os.path.join(i_dir, '*.mp4'))
        if len(mov_file_list) == 0:
            print('No files:', i_dir)
        
        for i_mov_file in mov_file_list:
            extract_frame(i_mov_file, i_dir, dryrun=False)         
 
    print('全て終了しました')



if __name__ == '__main__':
    main()