Transparent video for editors: ProRes 4444 and WebM with alpha

What "transparent" means in a video file

An ordinary video stores three numbers for every dot of the picture: how red, how green and how blue it is. A transparent video stores a fourth, called alpha, which says how see-through that dot is. Where alpha says "fully see-through", whatever lies underneath shows: your interview, your product shot, your web page.

The everyday MP4 file cannot carry alpha. That is why a transparent file is always a separate file, in a format built for it.

The two kinds, and which to pick

ProRes 4444 with alpha (.mov), for editing

This is the file an editor wants. Premiere, Final Cut, DaVinci Resolve and After Effects open it, put it on a track above your footage, and the background is simply not there. The quality holds up through editing and exporting again.

It is large, as editing files are, and some video players do not show it properly. That is normal: do not judge the file by double-clicking it. Open it in your editing program.

WebM with alpha (.webm), for the web

This is the file for a web page: much smaller, and played by the browser itself, so an animation can sit over your own background, photo or colour. Chrome, Edge and Firefox show the see-through parts. Some browsers, Safari among them, may not, so check the page on the devices your audience uses before it goes live.

When you need one, and when you do not

You need a transparent file when the animation is only one layer of something bigger:

• Titles, numbers and drawings laid over a person talking to camera.
• Callouts over a product video you already filmed.
• An animation at the top of a web page, over the page's own background.
• A layer your editor wants to time and position by hand.

You do not need one when the film is shown as it is, on a website, in a feed or in a presentation. Then the normal video file is simpler, smaller and plays everywhere.

How it works in Nine

On a finished film's page there is a part called Transparent, the animation on its own, with two buttons: Transparent, for editing (.mov) and Transparent, for the web (.webm). The background is left out and everything else stays. It is the picture only, with no sound, at the sharpness you chose for the video file.

• Which plans. Transparent files are part of Film + Transparent and the plans above it, up to 30 a month. After that, each file costs credits.
• The price is shown first. The price in credits stands on the button before you press. When the file is included in your plan, the button says how many are left this month.
• Sharpness. 1080p, and 2K or 4K on the plans that have them.
• Your edits come along. If you saved a version in the chamber, with other colours or a tall frame, the transparent file is that version. See editing a film yourself.

Some films cannot have one. A film drawn over your own video, and a film whose background is part of its picture, cannot be separated from it cleanly. The page says so in a sentence instead of showing the buttons.

If the layer is for a person talking, the Production and Studio plans can also make the film from that video directly: the film keeps the person and their voice, and puts what they say beside them.

How to do it in Nine

1. Open a finished film from Your films.
2. If you want other colours or another shape, change it in the chamber first and press Save.
3. On the film's page, choose how sharp under How sharp.
4. Under Transparent, the animation on its own, read the price on the button, then press Transparent, for editing (.mov) or Transparent, for the web (.webm).
5. When it is ready, put the .mov on a track above your footage in your editing program, or the .webm on your page.