Plex Prerolls Randomizer

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()

I've always been fond of those random MTV ads and have wanted to add some prerolls on Plex for a while, but I've always found that most of the prerolls online could be more varied, shorter, etc.

So, I had the idea to do MTV-style prerolls. The accompanying script will help you do that, too.

Here's how it works:

You have a folder (SRC_DIR) with random short videos that you think are funny. I strongly recommend downloading all the videos from @psychotronica_ on Twitter, as they are perfect for this.

Weekly (or at the interval you set the script to run), it will pick 10 videos in the SRC_DIR: 6 with 30 seconds or less, 2 with 40 seconds or less and 2 longer than 40 seconds. I'm trying to prevent long videos from being shown to users all the time, but you may be "lucky" to get one of these long ones.

It will output to the DEST_DIR you set in the script. Then all you have to do is add the list of prerolls with the names the script creates, in my case:

/config/prerolls/video1.mp4;/config/prerolls/video2.mp4;/config/prerolls/video3.mp4;/config/prerolls/video4.mp4;/config/prerolls/video5.mp4;/config/prerolls/video6.mp4;/config/prerolls/video7.mp4;/config/prerolls/video8.mp4;/config/prerolls/video9.mp4;/config/prerolls/video10.mp4;

Semicolons make Plex pick one of the prerolls at random.

That's it! I hope someone finds it useful. Occasionally, one of my friends says there is some weird video playing before watching a movie. I pretend I'm unaware of what they are talking about and ask them to describe what they see. It's a very entertaining experience that, unfortunately, doesn't last long as I can't keep my poker face up for too long.