How to Override ASS Subtitle Fonts in mpv?

This article provides a straightforward guide on how to force the mpv media player to ignore the embedded fonts within an Advanced SubStation Alpha (.ass) subtitle file and use your preferred system fonts instead. You will learn the exact configuration lines needed for your mpv.conf file, understand how these settings interact with subtitle styles, and discover how to handle potential rendering issues.

Step 1: Locate Your mpv Configuration File

To apply a permanent change, you need to edit your main configuration file, mpv.conf. Its location depends on your operating system:

• Windows: %APPDATA%\mpv\mpv.conf (e.g., C:\Users\YourName\AppData\Roaming\mpv\mpv.conf)
• Linux/macOS: ~/.config/mpv/mpv.conf

If the file or the mpv folder does not exist, simply create them manually as plain text.

Step 2: Add the Override Commands

Open mpv.conf in a text editor like Notepad, VS Code, or Nano, and add the following lines to completely override embedded styles and fonts:

# Force mpv to ignore embedded ASS styles and fonts
sub-ass-override=force

# Specify your preferred replacement font
sub-font="Arial"

# Optional: Adjust font size if the replacement looks too large or small
sub-font-size=50

Understanding the sub-ass-override Options

The sub-ass-override property is the crucial mechanism here. It accepts a few different values depending on how aggressive you want the override to be:

• force: Completely strips away the subtitle’s internal styling (fonts, colors, positions, and animations) and applies your default mpv subtitle styling instead.
• scale: Applies your custom subtitle font size adjustments while attempting to preserve the original font types and positions.
• yes: Overrides basic styling but respects custom font signs or complex typesetting where possible (though it can still break intricate layouts).

Using sub-ass-override=force is the most reliable way to guarantee that your custom sub-font selection is always used.

Step 3: Verify and Troubleshoot

Save the configuration file and open a video with ASS subtitles to test the changes. If your custom font is still not displaying, check for these common issues:

• Font Name Match: Ensure the font name in sub-font="Font Name" matches the exact system name of your installed font.
• Secondary Configuration Files: Check if you have directory-specific or file-specific profiles (like input.conf or script configurations) that might be conflicting with your mpv.conf settings.
• On-the-Fly Testing: You can test these settings in your terminal before committing them to the config file by running: mpv --sub-ass-override=force --sub-font="YourFont" video.mkv