Digital New Year’s fireworks: a small tutorial

Whomever you want to do a favor, the animals, the environment, your criminal record, or your wallet. Using a beamer to get a “digital” firework might be a good alternative to the “real thing” for you. Playing a YouTube video over a beamer is easy – but adding a countdown to your favorite video and positioning everything just right could be a challenge. That’s why I decided to write down how I do it.

How it’s done

• Install OBS Studio
• Pick a video background like this one and download it
  • Streaming it and using the browser window as a source works as well, but this method is susceptible to internet problems and might have worse performance in general
  • If you are on Linux, try youtube-dl or yt-dlp
  • Alternative video suggestions: 1
• Choose a website to display your countdown. I suggest using the “countdown until tomorrow“ from onlineclock.net
  • In contrast to their countdown to the new year specifically, you can set the background to black, which will allow you to select your own in a moment.
• In OBS, add the video sources:
  • Add a video source for the background
    • If your video is not very long, enable the loop option
  • Add a window source for the timer
    • Make sure this comes before the video source in the sources list
    • Right-click on this source and choose Blending Mode → Additive to (effectively) make the black background of the timer window transparent, so you can see your background video behind
  • Arrange the sources on the canvas to your liking (by dragging them)
  • If necessary, crop the sources via right-click → Transform → Edit Transform or Ctrl+E
• Connect your beamer and set it to extend (instead of mirror) your display
• Right-click the active scene on the bottom left and choose Fullscreen Projector (scene), followed by the video output that goes to the beamer
• The timer will disappear after it reaches zero, leaving the background video intact

How it could be improved

• My beamer isn’t particularly bright and is rather distant from the building it’s projecting on. While sufficient in the dark night, a better beamer or better positioning would improve the viewing experience.
• One could use a Bluetooth speaker, for example, to add to the realism.
• By mapping the features of the targeted building (such as windows, doors, roof…), laser-show-like effects could be achieved.