backdropGen

backdropGen is an interactive CLI tool written in Go. It automates the creation of video "backdrops" or themes-short, lightweight video loops —designed for media servers like Jellyfin, Emby, or Plex.

It intelligently scans your movie library, picks a high-quality segment from your films, and compresses them into 10-second previews to enhance your library's UI.

---

Features

• Batch & Single Mode: Process an entire root directory with hundreds of movies or target one specific directory.
• Smart Video Selection: Automatically identifies the largest video file in a directory (the actual movie) to use as the source.
• Concurrency: Built with Go routines to process multiple videos simultaneously, utilizing your CPU efficiently.
• Interactive UI: Features a guided terminal interface with directory auto-completion (Tab-to-complete).
• Audio Control:
  • Always: Keep the movie's soundtrack.
  • Never: Strip audio for silent, atmospheric loops.
  • Random: A 30% chance for audio (adds variety).
• Optimized Encoding: Downscales 4K/1080p content to 720p and uses a high CRF to keep file sizes tiny (typically under 50MB).
• Maintenance: Includes a "Remove All" mode to recursively delete backdrops directorys if you want to refresh your library.

---

Getting Started

Prerequisites

• Go: 1.18 or higher.
• FFmpeg & FFprobe: Must be installed and accessible in your system $PATH.

Installation

1. Clone the repository:

   git clone https://github.com/FahimAnayet/backdropGen.git
   cd backdropGen

2. Install dependencies:

   go get github.com/AlecAivazis/survey/v2

3. Build the binary:

   go build -ldflags="-s -w" -o backdropGen backdropGen.go

---

Usage

Run the executable:

./backdropGen

Options

1. Choose an Option: Select between Batch Creation, Single Creation, or Removal.
2. Enter Path: Provide the path to your media. (e.g., /mnt/media/Movies or ~/Videos).
3. Audio Prefs: Select how you want the tool to handle sound.
4. Monitor Progress: A real-time progress bar tracks the batch processing.

Debugging

If a specific video is failing to process, run with the debug flag to generate a debug.log:

./backdropGen -d

---

File Structure

The tool follows the standard media server convention for themes:

Films/
└── Interstellar (2014)/
    ├── Interstellar.2160p.mkv
    └── backdrops/            <-- Created by backdropGen
        └── Theme.mp4         <-- 10-second, 720p clip

---

Technical Logic

• Segment Selection: The tool picks a random start time at least 2 minutes into the movie (to avoid studio logos) and at least 5 minutes before the end (to avoid credits).
• FFmpeg Specs: * Codec: libx264 (Ultrafast preset).
  • Resolution: Capped at 720p height (scale=-2:720).
  • Framerate: Normalized to 24fps.
  • Bitrate: Capped at 1M maxrate to ensure fast loading over network streams.