🚀 YT-Smart-Assistant

Current Version: V1.0.3
(This is a massive milestone update)

https://github.com/user-attachments/assets/3e530969-429c-429b-94b0-dd165222e63d

📖 Introduction (简介)

YT-Smart-Assistant is a high-performance, privacy-focused media management tool. Unlike simple downloaders, it acts as an intelligent "Media Archiver", bridging the gap between browser interactions and high-end processing. YT-Smart-Assistant (YT智能助手) 是一个基于 Deno 全栈架构的流媒体智能归档助手。它不仅仅是一个下载器，更是一个部署在本地的“媒体归档管家”，通过油猴脚本与本地后端的配合，实现 4K 视频分析、字幕自动修复与无损封装。

🛡️ Security & Privacy (Zero Trust Architecture)

[!IMPORTANT] We build for safety. This project follows a "Paranoid-First" approach to ensure your data stays yours.

• 🔒 100% Localhost: The entire stack runs strictly on 127.0.0.1. Zero data is sent to third-party servers.
• 🛡️ XSS Immune: Strictly no innerHTML usage. All UI rendering uses secure text-node methods to prevent malicious metadata injection.
• 🚫 No Auto-Updates: There are no background update checks or "phoning home" scripts. You are in total control of your version.
• 📦 Bring Your Own Binaries: You manage your core dependencies (yt-dlp, ffmpeg). Update them manually via official sources whenever you want.
• ⚖️ The Bottom Line: If there is a "security" alert, it is a vulnerability within your browser or local OS, not this tool.

✨ Key Features

🎥 Core Downloading

• 🔍 Smart Analysis: Automatically filters out low-res garbage (144p/240p). Highest quality (4K/8K + AV1) is always prioritized at the top.
• ✂️ Precise Slicing: Supports frame-perfect time-range downloads.
• 🎯 Subtitle Slicing (Unique): Automatically repairs and slices subtitle tracks to match your specific video clip. No more out-of-sync captions.

🧠 Intelligent Subtitle Pipeline NEW

• 🔄 Auto-Fix: Built-in algorithms fix timestamp overlaps and merge fragmented lines.
• 🔥 Hot-Search Logic: Uses modification-time heuristics to locate files, ignoring OS filename character mangling (e.g., ? becoming _).
• 📦 Clean Muxing: Strips junk tracks (und, orig), keeping only high-quality English and Chinese tracks with correct metadata.
• 🧹 Zero-Trace: Instantly deletes .srt, .orig, and .tmp files after muxing.

🎨 Advanced UX

• 🖥️ UI Scaling: A dynamic slider to resize the interface for any screen size (from 13" laptops to 4K monitors).
• ⚡ Command Injection: Dedicated input for raw yt-dlp arguments. Injected with highest priority to override default behaviors.

🛠️ Tech Stack

• Backend: [Deno] (TypeScript) - Secure & modern runtime.
• Frontend: Tampermonkey / GreaseMonkey (JavaScript).
• Core Engine: yt-dlp & ffmpeg.

🚀 Installation

Step 1: Backend Setup

1. Go to the Releases page.
2. Download the latest YT-Assistant-Full.zip.
3. Unzip to any folder.

Step 2: Browser Setup

1. Install the Tampermonkey extension for your browser (Chrome, Edge, or Firefox).
2. Ensure "Allow access to file URLs" is enabled in Tampermonkey settings (if loading locally).

📁 File Structure

Maintain the following files in the same directory:

Root/
├── YT-Smart-Assistant.bat  <-- Run this!
├── script.user.js          <-- Install this in Tampermonkey
├── server.bundle.js
├── deno.exe
├── ffmpeg.exe
├── ffprobe.exe
└── yt-dlp.exe

🎮 Usage

• Launch Backend: Double-click YT-Smart-Assistant.bat. Keep the terminal open: 🚀 Service started at: http://localhost:6969.

• Install Frontend: Drag and drop script.user.js into your Tampermonkey Dashboard and click Install.

• Download: Open any YouTube video. Adjust settings on the floating panel and click "🚀 Download Now".

⚙️ Configuration & Troubleshooting

[TIPS] * Reset for New Video: If you want to analyze a different video or clear the current results, simply click the "Broom" (🧹) icon at the top of the panel to reset the analyzer and start fresh.

• Don't forget to load cookies! By default, the engine uses Firefox cookies. Ensure you are logged into YouTube in Firefox.

• Using Chrome/Edge? Open Advanced Settings (⚙️) in the UI and change the browser source.

🌐 Proxy & VPN (Clash / V2Ray)

Ensure "System Proxy" is enabled in your VPN client.

If downloads fail, try enabling TUN Mode.

You can manually input --proxy "http://127.0.0.1:PORT" in the UI command box.

⚠️ Disclaimer

This project is for educational and technical research purposes only. Please respect copyright laws and platform Terms of Service. The author assumes no responsibility for any misuse.

本项目仅用于技术研究与教育目的。请遵守相关法律法规及平台服务条款，切勿用于侵犯版权的行为。