Screen + camera

Upload a screen recording and a camera recording together, with both audio tracks mixed. Record both in the same session so they line up. Choose a layout:

• Picture-in-picture (default): the camera in a corner of the screen. {"type": "pip", "position": "bottom-right", "size": "medium"}; position is bottom-right, bottom-left, top-right or top-left, size is small, medium or large. "pip" means bottom-right, medium.
• Side by side: screen (~70%) and camera (~30%) next to each other on a dark background. {"type": "side-by-side", "screen": "left"} or "right".

POST /videos
{ "fileName": "screen.webm", "sizeBytes": 209715200,
  "layout": { "type": "pip", "position": "top-left", "size": "small" },
  "camera": { "fileName": "camera.webm", "sizeBytes": 52428800 } }

Changed your mind? Reprocess with another layout; nothing is uploaded again.

The response adds camera.partSize and camera.partCount. Request the camera's part URLs with "file": "camera", upload both files, then call complete once.