Define the destination first.
Start with the required aspect ratio, resolution, caption safe areas and player behavior. A 16:9 broadcast and a 9:16 portrait output have different geometry. The output resolution also depends on the source; reframing does not recover detail that was never captured.
Choose a layout before exporting.
For a single subject, a tracked portrait crop may be enough. For an interview, showing two speakers in stacked regions may communicate more than alternating tight crops. For a demonstration, preserve both the presenter and the relevant object.
Create the edit, then recompose.
Choose the right excerpt, ensure the opening makes sense without the full program, then adapt the composition. A trailer, teaser, social clip and complete vertical episode have different editorial goals even if they all use 9:16.
Review on a phone.
Check faces, action, lower thirds, captions and transitions at the actual viewing size. Look for unwanted jumps, missing context and unreadable graphics. Keep the original asset and source timestamps attached to the output for later revisions.
Why a simple converter struggles with broadcast footage.
Consumer converters usually apply one crop window, centered or following a face. That suits a single person talking to camera. Broadcast pictures add burned-in lower thirds, scoreboards and logos near the edges, presenters standing beside the graphic they explain, and panels of several speakers. A full-height 9:16 window keeps about a third of a 16:9 frame, so one of those elements is often lost. Vertical players also cover part of the picture: Meta's guidance for Reels ads suggests keeping at least 14% of the top, 35% of the bottom and 6% of each side free of text and logos. A broadcaster's workflow therefore needs layout rules per shot type, graphics moved clear of the interface, live as well as recorded sources, and a review step before publishing. Our guide to social video aspect ratios lists each platform's documented formats and safe zones.