Runway video check: what survives in the file
Runway output is video, and video carries its provenance in different places than a still image does. AICheck365 reads the MP4/MOV container first — ftyp, the box tree, udta/meta/ilst, encoder, tool and software fields — then looks for known tool strings in the bitstream, checks the download file name, and only samples frames when everything above comes back empty. The whole pass runs in your browser, which matters more for video than for images.
Short answer: container fields first, frames only as a fallback
Start from the original MP4 or MOV and read the container tool and encoder fields, then any SEI marker in the video bitstream. The download file name can carry a platform pattern worth noting. None of these are signed the way a C2PA manifest is, so each is a clue to be corroborated against where the file actually came from — and all of them are removed by a single re-encode.
Sample status and evidence profile
| Bundled Runway sample | Not bundled yet. This page does not claim a reproduced Runway test until a licensed original can be published alongside the other samples. |
|---|---|
| Related bundled video | A Google Veo MP4 is included and exercises the same container, SEI and frame paths, though the credentials it carries are Google's rather than Runway's. |
| Evidence level | Unsigned container metadata and file-name patterns: readable and useful, but materially weaker than a verifiable C2PA manifest. |
Signals to Check
| MP4/MOV container metadata | ftyp brand, box tree, udta/meta/ilst, encoder, tool, software and ©too entries are read where present, each reported with the box path it came from. |
|---|---|
| SEI markers | Known tool strings inside the video bitstream. They can survive a remux but usually disappear on re-encoding, making them a mid-to-weak clue. |
| File name | Download names sometimes carry a platform pattern or job identifier. Useful context, trivially renamed. |
| Sampled frame watermarks | When the container yields nothing, frames from several timestamps are checked against known visible marks and invisible patterns. Not a general AI classifier. |
Why an empty result is so common on shared clips
Video is transcoded far more aggressively than images, so evidence attrition is fast. A social platform re-encode typically removes container tool fields and SEI markers in one pass, leaving a file that plays identically and carries nothing readable. An editor that re-exports the timeline does the same, and a screen recording keeps none of the original container at all. This is why a blank result on a Runway clip is genuinely uninformative rather than exculpatory — and why finding the first published copy is usually worth more than any amount of frame-by-frame inspection.
Where Runway sits relative to platforms that sign
Some platforms attach C2PA Content Credentials to their output, which produces evidence that can be cryptographically verified and shown to be intact or broken. Descriptive container fields are a different category: readable, informative about which tool wrote the file, but editable by anyone with a metadata utility. When results from the two categories disagree, the signed layer wins — and when only the unsigned layer is present, the honest framing is that the file suggests an origin rather than proves one.
Limits
- Container fields, SEI markers and file names are unsigned: they can be edited, removed or copied onto another file.
- Transcoding by video platforms and messaging apps, re-exports and screen recordings remove them routinely.
- No bundled Runway sample is published yet, so this page describes field coverage rather than a reproduced test result.
- Frame analysis only matches currently known patterns and cannot replace source verification or professional forensics.
Start with the MP4/MOV metadata inspector, then open the full detector when you need the frame watermark fallback.
FAQ
How do I check whether a video came from Runway?
Load the original MP4 or MOV into the metadata inspector and read the container encoder and tool fields first. The check is free, runs in your browser without uploading the file, and reports each hit with the box path it came from.
Does Runway add C2PA Content Credentials?
Do not count on it. The dependable signals here are unsigned container metadata, SEI markers and the file name. If a signed manifest does appear, it was most likely added by a later step in the pipeline.
Why did the check find nothing on my clip?
Almost always because the file was re-encoded. Uploading to a video platform, re-exporting from an editor or screen-recording removes container fields and SEI markers while leaving the footage looking the same.
Are videos uploaded for checking?
No. Container parsing runs locally through Rust compiled to WebAssembly, and frame extraction, when it is needed, also runs on your machine.
Sources and verification records
- AICheck365 public sample records — Which video samples are bundled, their provenance, test dates and known limits.
- ISO/IEC 14496-12 (ISO base media file format) — The standard behind the MP4/MOV box structure this parser walks.
- AI video detection guide — The full container, bitstream and frame layering in one place.
- AICheck365 methodology — How video evidence layers, confidence tiers and limits are defined.