Video editing API
Edit video with a JSON file.
Llumi Cut takes your photos, clips, audio and a timeline, and hands back an MP4 ready to publish. Transitions, titles, effects, voice-over, subtitles and social formats. No editing app involved.
- 13transitions
- 12image effects
- 20audio tracks per video
- 3formats: 16:9, 9:16 and 1:1
- −16LUFS loudness target
What it does
Everything you'd do by hand in an editor, written down once and repeatable a thousand times.
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Photos and clips in one edit
Start a clip at any second, change its speed from 0.25× to 4×, or crop it to fill the frame.
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Sound from many sources
Song, voice-over, sound effects and each clip's own audio. The music ducks by itself when someone speaks.
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Animated titles
Titles, lower thirds and credits with nine positions, nine fonts, coloured boxes and six animations.
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Layers and split screen
Transparent logos, picture-in-picture, split screen and grids of several videos.
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Transitions and effects
Thirteen transitions, Ken Burns on stills, twelve colour looks and brightness, contrast and saturation.
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A format for every channel
Landscape for YouTube, vertical for Reels, Shorts and TikTok, square for feed posts.
How it works
Three HTTP calls. Renders run in a queue and you can check progress at any time.
Upload your media
Each photo, clip or audio file goes up in one request and comes back with an ID.
Send the timeline
A JSON file with shots, sound, titles and layers. It's validated before it's queued.
Download the result
An H.264/AAC MP4, the soundtrack as WAV, SRT and WebVTT subtitles and a technical report.
{
"title": "Summer sale",
"duration": 12,
"width": 1920,
"aspect": "9:16",
"transition": "fade",
"image_motion": "auto",
"clips": [
{"asset_id": "8f1c…", "duration": 6, "fit": "cover"},
{"asset_id": "2b7e…", "duration": 6, "effects": ["warm"]}
],
"audio_tracks": [
{"asset_id": "c41a…", "volume": 0.8, "duck": true, "fade_out": 2},
{"asset_id": "9d03…", "start": 1}
],
"texts": [
{"text": "-30 %", "start": 0.5, "end": 5, "size": 200, "animation": "pop"}
]
}13 examples, really rendered
Every video came out of the API from a JSON timeline. The media are test assets.
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Example 01 · 1280×720 · 18 s
Photo slideshow with music
Six photos with alternating Ken Burns moves, crossfades, music that fades in and out, a title and an end card.
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Example 02 · 1280×720 · 15 s
Chained video clips
One clip trimmed to start at second 1, one at double speed and one in slow motion, each keeping its own sound.
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Example 03 · 1280×720 · 20 s
Photos and video mixed
Photos and clips alternate, each change with a different transition, music starting mid-track.
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Example 04 · 1280×720 · 18 s
Voice-over with music
Three voice lines with subtitles. The music dips by itself while someone talks and comes back after.
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Example 05 · 1280×720 · 20 s
Titles and text
Nine positions, six animations, several fonts, coloured boxes, free placement and end credits.
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Example 06 · 1280×720 · 26 s
Image effects
Twelve looks plus brightness, contrast and saturation, each one labelled.
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Example 07 · 1280×720 · 26 s
Transition gallery
All thirteen transitions between shots, one after another.
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Example 08 · 1280×720 · 15 s
Picture-in-picture
A main video, a bordered inset video with sound, a photo on top and a transparent logo.
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Example 09 · 1280×720 · 12 s
Split screen
Two videos side by side, then a grid of four at once.
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Example 10 · 1080×1920 · 15 s
Vertical 9:16
For Reels, Shorts and TikTok: full-screen crop, large titles, voice and logo.
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Example 11 · 1080×1080 · 12 s
Square 1:1
A square post with a custom colour in the letterbox bars.
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Example 12 · 1280×720 · 26 s
Song with pauses
Two pauses of true digital silence over a frozen shot with a question on screen.
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Example 13 · 1920×1080 · 30 s
Everything together
All of the above in one 30-second 1080p video.
What people use it for
Online shops
A video per product from its photos, with price and logo, every time the catalogue changes.
Training and education
Lessons with voice, subtitles and pauses so learners can answer before moving on.
Property and lettings
Walkthroughs built from listing photos, with music and the key details on screen.
Social media at scale
The same piece in 16:9, 9:16 and 1:1 from a single timeline.
Products that generate video
Your app sends the JSON and gets the MP4 back, without relying on a third-party editing service.
Technical sheet
- Output
- MP4 H.264 + AAC 192 kbps, 24 or 30 fps
- Resolution
- 640, 1280 or 1920 px on the long side · 16:9, 9:16 and 1:1
- Length
- 3 to 600 seconds, exact to the frame
- Shots
- Up to 150, each up to 60 s
- Sound
- Up to 20 tracks, automatic ducking, normalised to −16 LUFS
- Titles and layers
- Up to 100 titles and 20 layers per video
- Deliverables
- video.mp4, audio.wav, song.wav, subtitles.srt, subtitles.vtt, qc.json
- Operations
- Persistent queue, idempotency, cancellation, retries and automatic clean-up
Frequently asked questions
Do I need video editing skills?
No. You describe the edit in JSON: which shot comes first, how long it lasts, what plays and which titles appear. The editor does the rest.
Which formats does it accept?
PNG and JPG images, MP4 video and WAV, MP3, OGG and FLAC audio. PNGs keep their transparency, so they work for logos.
How long does a render take?
In our tests, 8 to 70 seconds for videos of 12 to 30 seconds. It depends on resolution, number of shots and effects.
Where does it run?
On a server with FFmpeg: ours or yours. Your files aren't sent to third-party services to be edited.
Can I build it into my app?
Yes. It's an HTTP API with token authentication, idempotency and job status you can poll. The documentation is at /docs/.
How much does it cost?
It depends on how many videos you need and where it runs. Tell us what you need and we'll reply within one working day.
Want to try it with your own videos?
Tell us what you want to generate and how many videos a month. We'll reply within one working day.
info@nordicbyte.co.uk