If you want to turn the spoken words in 821.mp4 into a text document or captions, you can use these common methods:

: Use tools like ExifTool to extract technical text data (like camera settings, date, and GPS) embedded in the file. How to Create Bold Text for Captions Using Poppins Font

: Opening an MP4 in a Hex editor will show you the binary data in text form, though it will be unreadable to humans.

: Use light text on a dark background (or vice versa) and avoid placing text over "busy" parts of the video frame.

If you literally want to see the "text" that makes up the binary file for technical debugging:

: If you have a Microsoft 365 account, you can use the Transcribe feature in Word online to upload an MP4 and get a full text readout.