# How do I turn a 16:9 video into 9:16 without cutting off the speaker?

Canonical page: https://remixviral.ai/en/solutions/horizontal-to-vertical-video | Last updated: 2026-11-13 | By RemixViral (https://remixviral.ai)

Cropping a 1920x1080 frame to 9:16 keeps only about 31.6 percent of its width, so choose the layout by where the speaker sits. Use a centred crop for a centred speaker, a shifted crop for an off-centre one, a blurred-background fit for slides or wide shots, and a stacked layout for two side-by-side speakers. Then watch every clip.

## Why the speaker gets cut off

A 16:9 frame is wide and a 9:16 frame is tall, so reframing is not a resize, it is a choice about which part of the picture to throw away. Take a 1920x1080 source. A 9:16 window as tall as the source is 1080 x 9 / 16 = 607.5 pixels wide (ffmpeg truncates that to 607). That is 607 / 1920 = 0.316, so about 31.6 percent of the width survives and about 68 percent is discarded. The window is then scaled up to 1080x1920, an enlargement of roughly 1.8 times, which is why a crop looks softer than the original.

Cut the middle third of a frame and anything outside it disappears: a presenter standing to one side, a guest at the edge, a slide, a chart, text that runs across the screen. A centred crop is only safe when the subject is centred and stays there. Interviews, panels and screen recordings usually break that assumption.

A crop made by a fixed formula also cannot follow motion. If the speaker walks across the stage during the clip, a window placed at one x position will cut them off partway through, however carefully you chose it at the start. That is the main limit of every method below, so the final step is always to watch the result.

## Four layouts, with commands that work (no special tool needed)

All of these use ffmpeg on a video you own and are the commands from our tested ffmpeg post, run there against a 1920x1080 test source: each exited with code 0 and ffprobe reported h264, 1080x1920, yuv420p. They cut 10 seconds starting at 5 seconds; change -ss and -t to your moment. The free [aspect ratio calculator](https://remixviral.ai/en/tools/aspect-ratio-calculator) does the width arithmetic for other source sizes.

1. **Centre crop: when the speaker is in the middle and stays there.** Keep a full-height vertical strip from the middle of the frame and scale it to 1080x1920. For a 1920x1080 source the strip is about 607 pixels wide. This is the right pick for a talking head filmed straight on, and the wrong one for anything with the subject off-centre.

   ```
   ffmpeg -ss 5 -i input.mp4 -t 10 \
     -vf "crop=ih*9/16:ih:(iw-ih*9/16)/2:0,scale=1080:1920,setsar=1" \
     -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p \
     -c:a aac -b:a 128k -movflags +faststart clip.mp4
   ```

2. **Shifted crop: when the speaker is off-centre but stays put.** Replace the centring expression with a fixed x offset in pixels, the left edge of the window. Step 4 below shows how to choose the number. Example with x = 300 on a 1920-wide source (the window then covers pixels 300 to 907).

   ```
   ffmpeg -ss 5 -i input.mp4 -t 10 \
     -vf "crop=ih*9/16:ih:300:0,scale=1080:1920,setsar=1" \
     -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p \
     -c:a aac -b:a 128k -movflags +faststart clip.mp4
   ```

3. **Blurred-background fit: when you cannot afford to lose any of the frame.** Keep the whole 16:9 frame in the middle of the 9:16 canvas and fill the space above and below with a blurred, enlarged copy of the same video. Nothing is cropped, but the picture is smaller (1080 pixels wide, about 608 tall in the centre), so on-screen text is smaller too. Good for slides, screen recordings, wide shots and group scenes.

   ```
   ffmpeg -ss 5 -i input.mp4 -t 10 \
     -filter_complex "[0:v]split=2[bg][fg];\
   [bg]scale=1080:1920:force_original_aspect_ratio=increase,crop=1080:1920,boxblur=30:5[bgb];\
   [fg]scale=1080:-2[fgs];\
   [bgb][fgs]overlay=(W-w)/2:(H-h)/2,setsar=1[v]" \
     -map "[v]" -map 0:a \
     -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p \
     -c:a aac -b:a 128k -movflags +faststart clip.mp4
   ```

4. **Stacked layout: two people side by side.** Crop the left and right halves of the frame and stack them, speaker A on top and speaker B below. It assumes each person sits inside their own half of a 1920x1080 frame, which you must check. Each tile becomes 1080x960, so the two together are exactly 1080x1920. Adjust the y value of 113 to move the windows up or down.

   ```
   ffmpeg -ss 5 -i input.mp4 -t 10 \
     -filter_complex "[0:v]split=2[a][b];\
   [a]crop=960:854:0:113,scale=1080:960[top];\
   [b]crop=960:854:960:113,scale=1080:960[bot];\
   [top][bot]vstack=inputs=2,setsar=1[v]" \
     -map "[v]" -map 0:a \
     -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p \
     -c:a aac -b:a 128k -movflags +faststart clip.mp4
   ```

5. **Find the x offset for an off-centre speaker.** First read the source size, then grab a frame from the moment you are clipping, estimate where the speaker's face is horizontally, and subtract half the window width (about 304 pixels for 1080p) so the face lands in the middle of the window. Keep x between 0 and the frame width minus 607. Example: a face centred at pixel 480 gives x = 480 - 304 = 176. Preview the crop on one frame before you render the clip, and check a frame from the end of the clip too, in case the person moves.

   ```
   ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=p=0 input.mp4
   ffmpeg -ss 5 -i input.mp4 -frames:v 1 frame.png
   ffmpeg -ss 5 -i input.mp4 -frames:v 1 -vf "crop=ih*9/16:ih:176:0" preview.png
   ```

## What a fixed crop cannot do

None of the four layouts follows a moving subject. Following a speaker means analysing the video to find faces or voices over time and moving the window, which is a different job from a crop filter. We do not document face tracking or speaker following in RemixViral, so we do not claim it: treat the layout as a starting point and check each clip.

If a clip has movement that a fixed window cannot hold, shorten the clip to the part where the subject stays put, switch to the blurred-background fit for that clip, or reframe by hand in an editor that supports keyframes.

### Which layout for which footage

| Layout | Use it when | What it gives up |
|---|---|---|
| Centre crop | One speaker, centred, mostly still | About 68 percent of the width of a 16:9 frame; anything off-centre |
| Shifted crop | One speaker, off-centre, mostly still | The same 68 percent; the speaker is lost if they walk out of the window |
| Blurred-background fit | Slides, screen shares, wide shots, groups | Picture size: the frame is 1080 pixels wide and about 608 tall inside a 1920-tall canvas |
| Stacked | Two speakers side by side, each in their own half | Vertical room per person; it fails if a person crosses the middle line |

## When to use RemixViral

RemixViral reframes for you as part of cutting clips from a video you upload. In a job you choose the layout: auto, crop (fill) or stack (split), and the output aspect: 9:16, 1:1 or 16:9. Captions are burned in, and you review and export each clip in the dashboard.

Use it when:

- You want many vertical clips from one long recording without writing a command per clip.
- You want a choice between a filled crop and a stacked split layout per job, rather than one fixed formula.
- You will review each clip: look at the first and last second for a cut-off face before exporting.

It is not the right tool when:

- You need guaranteed subject tracking through movement: we do not document face tracking or speaker following. Use an editor with keyframed reframing or tracking for that footage.
- You need a frame-accurate crop you position yourself: RemixViral has no timeline editor; use ffmpeg as above, or a video editor.
- You have one clip to reframe: the commands above take a minute and cost nothing.

## Ask your AI assistant to do it

After a clip job has finished, an AI assistant can read the ranked clips and tell you which are worth watching first for framing problems. It cannot see the video, so you still look at each clip.

```text
Assign to RemixViral: use list_clip_jobs to find my latest finished clip job, then get_clip_job to read its ranked clips. For each of the top five, list start and end seconds, score and reason, and flag any whose reason mentions a second speaker, a slide or a demo, because those are the ones most likely to need a stacked or fit layout. Do not create anything. Show me what you did so I can approve which clips I check first.
```

Connection steps and the full tool list: https://remixviral.ai/en/mcp

## Frequently asked questions

### How much of a 16:9 video is left after cropping to 9:16?

For a 1920x1080 frame, a full-height 9:16 window is 1080 x 9 / 16 = 607.5 pixels wide, so about 607 of 1920 pixels, roughly 31.6 percent of the width. The rest is discarded, and the window is scaled up about 1.8 times to reach 1080x1920.

### Can I turn 16:9 into 9:16 without cropping anything?

Yes, with a fit layout: the whole frame sits in the middle of a 9:16 canvas and the empty space above and below is filled, for example with a blurred copy of the video. The trade-off is a smaller picture, so small text becomes harder to read.

### Does RemixViral follow the speaker with face tracking?

We do not document face tracking or speaker following, so we do not claim it. You can choose a layout (auto, crop or stack) per job and review every clip before exporting.

### Which layout should I use for a podcast with two people?

If both are visible side by side, a stacked layout puts one above the other and keeps both in frame. If only one person is on screen at a time, a crop is usually fine. Check the clip around speaker changes either way.

## Sources

- [FFmpeg Filters Documentation (crop, scale, overlay, vstack)](https://ffmpeg.org/ffmpeg-filters.html) (read 2026-11-13)

## Related

- [ffmpeg commands: 16:9 video to vertical 9:16 Shorts](https://remixviral.ai/en/blog/ffmpeg-commands-horizontal-to-vertical-shorts)
- [Aspect ratio calculator](https://remixviral.ai/en/tools/aspect-ratio-calculator)
- [How do I turn a long video into YouTube Shorts with AI?](https://remixviral.ai/en/solutions/long-video-to-youtube-shorts)
- [What size, frame rate and bitrate should I export at?](https://remixviral.ai/en/solutions/video-export-settings-shorts-reels-tiktok)

All problems and solutions: https://remixviral.ai/en/solutions | machine-readable list: https://remixviral.ai/solutions.json