Pan and scan a 1.85:1 trailer to vertical: one crop per shot

To turn a 1.85:1 film trailer into a vertical cut, treat each shot as its own crop. Video filter takes a crop rectangle as fractions, so one shot can sit at x: 0.1 and the next at x: 0.55, following the action. Use video trim to cut each shot, video filter to crop it, and Timeline 1.0 to join them. A centre crop of a 1.85:1 frame keeps only 30.4 percent of the width, so the choice of offset is the editorial decision.

The width and the range of x

For 9:16 from 1.85:1, the crop width is 0.5625 / 1.85 = 0.304054. At 1998x1080 that is 607.5, which rounds down to 606 px. The offset can run from 0 (left edge) to 1 - 0.304054 = 0.695946 (right edge); centre is 0.347973. The program also requires x + width <= 1, or the request fails with video_filter_crop_out_of_bounds.

Job plan for a three-shot cut

Each shot is two jobs. A trim at $0.02 and a filter at $0.02 is $0.04 per shot, so three shots are $0.12 before assembly. The filter's source must be 300 seconds or shorter, and a single trim output covers the shot. The trim happens first and writes a new MP4, which the filter then reads.

• Trim shot A: start and duration, precision: exact for a frame-accurate in-point.
• Trim shot B and C the same way, with their own ranges.
• Filter each with its own crop x, plus scale=1080:1920 in the filtergraph.
• Put the three outputs into timeline_create video[], with source_in 0 on each.

Timeline assembly

Timeline needs an audio spine and ordered slots, so a trailer with its own soundtrack can come in through audio detach, which returns a wav by default. Slot starts must increase and the first must be 0. A fade of up to 1 second can sit between slots after the first, capped at half the shorter neighbour. Pan-and-scan cuts usually read better as hard cuts, so skip the transition.

{
  "video_url": "https://media.sume.com/artifacts/artf_demo/shot-b-trimmed.mp4",
  "ops": [
    { "op": "crop", "x": 0.55, "y": 0, "width": 0.304054, "height": 1 }
  ],
  "filtergraph": "scale=1080:1920"
}

A caution on rights

Cropping a film changes the framing the filmmaker chose. Only work on footage you hold the rights to, and keep the original delivery next to the vertical cut so the editorial change is documented.