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MegaDownloader’s main interface provides a simple workflow for downloading media from YouTube and other supported platforms using yt-dlp.

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Main Interface Overview

The main panel (MainPanel.java:30) is the primary interface for downloading media. It features:
  • URL input field - Text field for pasting video URLs (urlField)
  • Download button - Initiates the download process
  • Audio-only checkbox - Extract audio as MP3 instead of video
  • Progress bar - Real-time download progress tracking
  • Play button - Opens the last downloaded file
  • Advanced options - Custom yt-dlp arguments

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Downloading Videos

1

Paste the Video URL

Copy a YouTube or supported platform URL and paste it into the URL field at the center of the main panel (MainPanel.java:358).The field has a tooltip: “Paste Video URL”
2

Click Download

Click the Download button to start the download process (MainPanel.java:362).The application will:
  • Validate the URL is not empty
  • Check that yt-dlp path is configured
  • Retrieve the download directory from config
  • Start a background download using SwingWorker
3

Monitor Progress

Once the download starts:
  • The Download button changes to “Downloading…” and becomes disabled
  • A progress bar appears showing real-time percentage completion (MainPanel.java:382-384)
  • The progress bar parses yt-dlp output to extract percentage values (MainPanel.java:630-637)
4

Download Completion

When the download completes successfully:
  • A success dialog appears: “Download completed successfully!”
  • The “Play Last Downloaded File” button becomes visible (MainPanel.java:665)
  • The URL field displays: “Insert new URL to download new video”
  • If M3U playlist creation is enabled, a playlist file is generated
The download runs in a background SwingWorker thread (MainPanel.java:546) to prevent the UI from freezing during long downloads.

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Download Configuration

The download process uses several configuration options:

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yt-dlp Path

The application reads the yt-dlp executable path from config.txt (MainPanel.java:174-191): 
path:"C:\\path\\to\\yt-dlp.exe"
If not configured, you’ll see an error: “yt-dlp path not configured. Please go to Edit > Preferences to set the path.”

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Download Directory

Media files are saved to the configured download directory (MainPanel.java:199-216): 
downloadDir:"C:\\Users\\YourName\\Downloads"
The output template is: %(title)s.%(ext)s (MainPanel.java:565)

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Speed Limiting

If the speed limiter is enabled in Preferences, downloads are rate-limited using yt-dlp’s --limit-rate option (MainPanel.java:559-562): 
yt-dlp --limit-rate 1000K <url>

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Playing Downloaded Files

After a successful download, the Play Last Downloaded File button appears (MainPanel.java:386-395).
1

Click the Play button

The button opens the most recently downloaded file using your system’s default media player.
2

System Integration

The application uses Java’s Desktop API to open the file (MainPanel.java:714-717):
Desktop.getDesktop().open(lastDownloadedFile);
If the file doesn’t exist or Desktop operations aren’t supported, you’ll see an error message.

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Advanced Options

The Advanced toggle button (tglAdvancedOptions) reveals a custom arguments panel for power users (MainPanel.java:785-796).

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Using Custom Arguments

1

Click Advanced ▼

Click the Advanced ▼ button to expand the custom arguments panel.The button changes to Advanced ▲ when expanded.
2

Enter Custom yt-dlp Arguments

Enter any valid yt-dlp command-line arguments in the text area (txtAreaCustomArgs).Example:
--format "bestvideo[height<=720]+bestaudio/best"
3

Download with Custom Args

When you click Download, the custom arguments are parsed and appended to the yt-dlp command (MainPanel.java:577-588).Arguments are split by spaces while respecting quoted strings.
Custom arguments are useful for:
  • Selecting specific video quality/format
  • Adding subtitles (--write-subs)
  • Downloading playlists with custom filters
  • Any other yt-dlp feature not exposed in the UI

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Error Handling

The download process includes comprehensive error handling:

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Common Errors

Error: “Please enter a valid video URL”Cause: The URL field is empty or contains placeholder textSolution: Paste a valid video URL
Error: “yt-dlp path not configured. Please go to Edit > Preferences to set the path.”Cause: The config.txt file doesn’t contain a valid yt-dlp pathSolution: Go to Preferences and set the yt-dlp location
Error: “Download failed with exit code: X”Cause: yt-dlp process exited with a non-zero exit codeSolution: Check the console output for yt-dlp error messages. Common causes:
  • Invalid URL
  • Video unavailable or region-locked
  • Network connectivity issues
  • Disk space issues

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Progress Tracking

The download progress is tracked by parsing yt-dlp’s stdout output (MainPanel.java:597-639): 
if (line.contains("[download]") && line.contains("%")) {
    String percentStr = line.substring(line.indexOf("]") + 1, line.indexOf("%")).trim();
    double percent = Double.parseDouble(percentStr);
    publish((int) percent);
}
The progress bar updates in real-time as yt-dlp reports download percentage.

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Keyboard Shortcuts

  • ESC - Exit the application (MainPanel.java:158-168)
  • Enter (in URL field) - Trigger URL field action

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Next Steps

Extract Audio

Learn how to download audio-only files as MP3

Manage Downloads

Browse, search, and manage your downloaded media

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