A transparent video background needs more than a checkerboard
An alpha channel describes transparency. A checkerboard in an editor is usually a way to display that transparency, not a background you want baked into the picture. Before exporting, check whether the checkerboard is only a viewing aid or an actual image layer.
A file that appears black in a player is not enough to determine whether transparency was preserved. Test it in a composition with another layer behind it.
Check format, codec and destination
The filename extension does not tell you everything about the encoded video. Verify that the selected codec and export settings support the transparency you need, then confirm that the destination can read them.
Apple identifies ProRes 4444 and 4444 XQ as ProRes variants that support alpha channels. That does not mean every file using a familiar container includes alpha, or that every destination accepts that codec.
A short export test
- Choose a few seconds containing movement around the subject’s edge.
- Export using the intended transparency settings in your editor.
- Import that exported file into a fresh composition.
- Place a light layer and then a dark layer beneath it.
- Inspect the outline and play the entire test.
- Test the same file in the final destination before exporting the full project.
Keep the source project until you have confirmed the delivery works. A successful preview inside the original editor is not the final test.
A common misunderstanding
Suppose a presenter is visible over a checkerboard. If that checkerboard was exported as picture content, placing another layer below the clip will not reveal the new scene. You have a video of a checkerboard, not the intended transparent region.
Similarly, a solid black background may be picture content or the player’s display of an empty area. Use a compositing test instead of guessing from the player window.
What the 3YTV sample shows
The sample portrait has a transparent image background, so the workspace can display different colors behind it. This is a still-image demonstration, not a transparent-video export.
3YTV does not encode alpha-channel video. Use the sample to understand the visual idea, and use your editing application’s documentation and export test to verify an actual deliverable.
Put your next step into practice
Open the 3YTV workspace to try the sample controls. For another part of the decision, read change a video background without losing the subject.