Predator

A simple desktop app for grabbing videos and audio from YouTube and Instagram. Built with Go and Wails (web tech frontend), using yt-dlp under the hood to do the heavy lifting.

Table of Contents

• Features
• Getting Started
• How to Use
• Keyboard Shortcuts
• Technical Details
• Requirements
• Troubleshooting
• Contributing
• License

Features

Video Downloads

• Multiple resolutions - From 144p up to 4K (2160p)
• Best quality option - Automatically picks the highest available
• Smart codec handling - Uses H.264 video + AAC audio for maximum compatibility
• WebM support - Available with VP9/AV1 + Opus for better quality

Audio Downloads

• Multiple formats - MP3, M4A, Opus, or WAV
• High quality output - Uses best available source and converts to your chosen format
• MP3: V0 quality (~245kbps)
• M4A: AAC 192kbps
• WAV: 16-bit PCM 44.1kHz stereo

Platform Support

• YouTube - Videos, shorts, live streams
• Instagram - Reels, posts, stories, TV videos

User Experience

• Playlist support - Download entire playlists or select specific videos
• File size preview - See file sizes before downloading
• Live progress - Real-time speed, ETA, and percentage tracking
• Cancel anytime - Clean cancellation with automatic temp file cleanup
• Auto-retry - Failed downloads retry up to 3 times automatically
• Duplicate detection - Warns if content was already downloaded
• Custom download folder - Set once, remembers forever
• Download history - View past downloads, filter by type, open file location

Getting Started

You'll need Go 1.24 or newer installed.

# Clone the repository
git clone https://github.com/Aswanidev-vs/Predator.git
cd Predator

# Install dependencies
go mod download

Running the App

Development mode:

wails dev

Build for production:

wails build

First time setup: The app will ask to download yt-dlp and ffmpeg automatically. Just say yes - it handles everything and caches them locally. No need to install anything else manually.

How to Use

1. Open the app - It'll show the main download tab
2. Set your download folder - Click "Change Download Location" (or it'll use the current folder)
3. Paste a URL - YouTube or Instagram links both work
4. Pick your format:
   • For video: Choose resolution (144p to 4K, or "best")
   • For audio: Pick format (MP3, M4A, Opus, WAV)
5. Hit download - Watch the progress bar do its thing

Pro tips:

• Playlists show a modal where you can select specific videos to download
• Click the folder icon in history to open where a file is saved
• The app auto-updates yt-dlp to the latest version on each download

Technical Details

Video Format

• Container: MP4 (with WebM option)
• Video codec: H.264 (avc1) for maximum device compatibility
• Audio codec: AAC (m4a) for best audio quality
• Fallback handling: If preferred codec isn't available, automatically falls back to next best option

Audio Format

• Uses best available source (webm/opus or m4a/aac) and converts to your chosen format using ffmpeg

File Locations

• Downloads: User-selected folder or PREDATOR_OUTPUT_DIR environment variable
• History: ~/.predator/history.json (keeps last 100 items)
• Settings: ~/.predator/settings.json
• Dependencies: ~/.cache/yt-dlp/ (yt-dlp, ffmpeg, ffprobe)

Performance

• Concurrent downloads: Max 3 at a time to not overwhelm your connection
• Progress updates: Every 200ms for smooth progress bars
• Speed smoothing: Uses exponential moving average for stable speed display

Cleanup

• Cancelled downloads automatically clean up .part and temp files
• Failed downloads after max retries also trigger cleanup

Requirements

• Go 1.24+
• Internet connection
• yt-dlp and ffmpeg (auto-installed on first run)

Troubleshooting

"ffmpeg not found" error

The app will prompt you to download ffmpeg on first run. If you skip it, you can:

1. Install ffmpeg manually from ffmpeg.org
2. Or delete ~/.cache/yt-dlp/ and restart the app - it'll ask again

Slow downloads

• Check your internet connection
• YouTube might be throttling (try a different resolution)
• Max 3 concurrent downloads - close other apps using bandwidth

Download fails with "format not available"

• Try a lower resolution
• The video might be region-locked or unavailable
• Try using "best" option for auto-selection of best available

"Permission denied" errors

• Check if your download folder is writable
• Try a different download location

Contributing

Contributions are welcome! Please read the CONTRIBUTING.md file for guidelines.

Legal Stuff

This tool is for educational and personal use only.

• Respect copyright laws and YouTube's Terms of Service
• Only download content you own or have permission to download
• Don't use this to redistribute copyrighted material
• The authors aren't responsible for how you use this tool

Basically: be cool, don't pirate stuff you shouldn't.

License

MIT License - see LICENSE file.

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Built with Wails + Go + vanilla JS. No React, no bloat.