External Download Server

The External Download Server feature allows you to offload video downloads to a secondary server, saving bandwidth on your main WordPress server. This is particularly useful for high-traffic websites.

How It Works

When enabled, download requests are routed through an external PHP script hosted on your secondary server. The download is processed securely with:

• AES-256-CBC Encryption - Download URLs are encrypted to prevent tampering

• HMAC Signature Verification - Requests are signed using your Token Security Key

• Link Expiration - Download links automatically expire for security

• Platform-Optimized Streaming - Different download strategies for each platform

Setup Instructions

Step 1: Generate Token Security Key

1. Go to Visolix Video Downloader → Settings → General

2. Click Generate Token button next to "Token Security Key"

3. Click Save Settings

[!IMPORTANT] The Token Security Key is required for secure communication between your WordPress site and the external server.

Step 2: Download the External Script

1. Go to Visolix Video Downloader → Settings → External Download Server

2. Click the Download visolix-dl.php button

3. The downloaded file is pre-configured with your Token Security Key

Step 3: Upload to External Server

1. Upload visolix-dl.php to your external server (VPS or dedicated server)

2. Ensure the file is accessible via HTTP/HTTPS (e.g., https://dl.example.com/visolix-dl.php)

Server Requirements

Requirement	Minimum
PHP Version	8.0+
PHP Extensions	OpenSSL, cURL
Memory Limit	256MB+
Execution Time	Unlimited (recommended)

Step 4: Configure Plugin Settings

1. Go to Visolix Video Downloader → Settings → External Download Server

2. Enter your External Server URL (e.g., https://dl.example.com/visolix-dl.php)

3. Select which Platforms should use the external downloader

4. Click Save Settings

Enabled Platforms

You can choose which platforms use the external download server. Unselected platforms will continue to download through your main WordPress server.

Supported Platforms:

• Instagram

• TikTok

• Facebook

• Snapchat (non-HLS only)

• ShareChat

• Moj

• Telegram

• Ok.ru (Odnoklassniki)

Limitations

[!WARNING] HLS Streams Not Supported

The external download server does not support HLS/m3u8 video streams (e.g., Snapchat stories). These downloads require FFmpeg and will always be processed through your main WordPress server, regardless of platform settings.

Security Features

Feature	Description
Encrypted Payloads	Download URLs are AES-256-CBC encrypted
HMAC Signatures	Requests are verified using SHA-256 HMAC
Link Expiration	Download links expire after a set time
Platform Headers	Platform-specific headers prevent access issues

Environment Variables (Optional)

Instead of hardcoding the secret key, you can use environment variables on your external server:

# Add to your server environment
export VISOLIX_SECRET_KEY="your_token_security_key_here"

The script will automatically use this if the key is not hardcoded.

Troubleshooting

Downloads Not Starting

1. Verify the External Server URL is correct and accessible

2. Ensure the Token Security Key matches in both plugin settings and the PHP script

3. Check that the external server has cURL and OpenSSL extensions enabled

403 Forbidden Errors

• The download link may have expired

• The Token Security Key might not match between plugin and external script

• Regenerate the Token Security Key and re-download the script

Slow Downloads

• Ensure your external server has sufficient bandwidth

• Check if your external server has output buffering disabled

• Verify max_execution_time is set to 0 (unlimited)

Best Practices

1. Use HTTPS - Always use HTTPS for your external server URL

2. Dedicated Server - Use a VPS or dedicated server with good bandwidth

3. CDN Compatible - Place the external server geographically close to your users

4. Monitor Usage - Track bandwidth usage on your external server

5. Regular Updates - Re-download the script after plugin updates for latest optimizations