video_tool.py

import ffmpeg


def convert_video_to_audio(input_file, output_file, start_time, end_time):
    (
        ffmpeg
        .input(input_file, ss=start_time, to=end_time)
        .output(output_file, format="wav", acodec='pcm_s16le')
        .run(overwrite_output=True)
    )


def add_subtitle_to_video(input_file, subtitle_file, output_file, start_time, end_time):
    (
        ffmpeg
        .input(input_file, ss=start_time, to=end_time)
        .output(output_file, vf='subtitles=' + subtitle_file, preset='ultrafast', acodec='copy')
        .run(overwrite_output=True)
    )