salmutt/jellyfin-pretranscode repository overview

⁠Jellyfin Pre-Transcode Plugin

A Jellyfin plugin that automatically pre-transcodes the next episode when you reach the credits, so it starts playing instantly with zero buffering delay.

⁠How It Works

1. Credits Detection — When you're watching a TV episode, the plugin monitors your playback position. It detects credits using chapter markers (if available) or a configurable time threshold (default: 90% of runtime).

2. Next Episode Resolution — Once credits are detected, the plugin finds the next episode in the series, handling season boundaries automatically.

3. Background Transcoding — The next episode is transcoded in the background using FFmpeg at below-normal CPU priority, so it doesn't impact your current stream.

4. Direct-Play Injection — The cached MP4 is registered as a direct-play media source via Jellyfin's IMediaSourceProvider API. The client sees it as the preferred source and plays it instantly with zero transcode delay.

5. Seamless Resume — When the cached segment ends, the client resumes from the original source at the correct position. Jellyfin transcodes from that point forward with -ss seeking.

⁠Installation

⁠Docker (recommended)

Use the pre-built Jellyfin image with the plugin included:

docker pull salmutt/jellyfin-pretranscode:latest

Or in a docker-compose.yml:

services:
  jellyfin:
    image: salmutt/jellyfin-pretranscode:latest
    ports:
      - 8096:8096
    volumes:
      - ./config:/config
      - ./media:/media
    restart: unless-stopped

⁠From Release

1. Download the latest Jellyfin.Plugin.PreTranscode.dll from the releases page⁠
2. Create a directory: <jellyfin-data>/plugins/PreTranscode/
3. Copy the DLL into that directory
4. Restart Jellyfin

⁠From Source

git clone https://github.com/SalMutt/jellyfin-pretranscode.git
cd jellyfin-pretranscode

dotnet build Jellyfin.Plugin.PreTranscode -c Release

cp Jellyfin.Plugin.PreTranscode/bin/Release/net9.0/Jellyfin.Plugin.PreTranscode.dll \
   <jellyfin-data>/plugins/PreTranscode/

⁠Configuration

After installation, go to Dashboard > Plugins > Pre-Transcode in the Jellyfin web UI.

⁠API Endpoints

The plugin exposes REST endpoints for monitoring and management:

⁠Requirements

• Jellyfin Server 10.11+
• .NET 9.0 runtime (included with Jellyfin)
• FFmpeg (included with Jellyfin)
• NVIDIA GPU with NVENC support (optional, for hardware-accelerated transcoding)

⁠Building & Testing

# Build
dotnet build

# Run tests
dotnet test

# Publish release
dotnet publish Jellyfin.Plugin.PreTranscode -c Release

⁠License

Apache License 2.0. See LICENSE⁠ for details.