Plex Pre-roll randomizer: Grabs 10 prerolls from a directory full of videos, being 6 < 30s, 2 30-40s, 2 of the rest

setup_prerolls.py

#!/usr/bin/python3
import os
import random
import subprocess
import shutil

SRC_DIR = os.getenv('SRC_DIR', '/mnt/user/appdata/plex/source_prerolls')
DEST_DIR = os.getenv('DEST_DIR', '/mnt/user/appdata/plex/prerolls')

def get_duration(filename):
    cmd = [
        'docker', 'run', '--rm', '-v', f'{SRC_DIR}:/videos', '--entrypoint', 'ffprobe', 
        'linuxserver/ffmpeg', '-v', 'error', '-show_entries', 'format=duration', 
        '-of', 'default=noprint_wrappers=1:nokey=1', f'/videos/{filename}'
    ]
    result = subprocess.run(cmd, capture_output=True, text=True)
    return float(result.stdout.strip())

def get_files():
    categorized_files = { 'short': [], 'medium': [], 'long': [] }

    for file in os.listdir(SRC_DIR):
        if file.endswith('.mp4'):
            duration = get_duration(file)
            if duration <= 30:
                categorized_files['short'].append(file)
            elif 30 < duration <= 40:
                categorized_files['medium'].append(file)
            else:
                categorized_files['long'].append(file)

    return categorized_files

def copy_files():
    categorized_files = get_files()
    selected_files = []

    for cat, count in [('short', 6), ('medium', 2), ('long', 2)]:
        selected_files += random.sample(categorized_files[cat], count)

    for i, file in enumerate(selected_files, 1):
        shutil.copy(os.path.join(SRC_DIR, file), os.path.join(DEST_DIR, f'video{i}.mp4'))

if __name__ == "__main__":
    copy_files()