If you are describing the quality and size of a download or stream: 720p High Definition File Size: 999MB
"Just finished the export: Ready to upload!" 720p [999MB]
Here are a few ways to "put together" that text depending on where you plan to use it: For a File Name or Media Library If you are describing the quality and size
If you are naming a video file or organizing a digital collection: Video_Project_Final_720p_999MB.mp4 For a Technical Specification 720p [999MB]