> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pureframe.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Exact Timestamps

> What timestamp_start and timestamp_end actually represent, and their real precision.

Every segment carries `timestamp_start` and `timestamp_end` in seconds, marking where in the source video that match occurs. Precision depends on which signal produced the segment.

## Frame and scene segments

Frames are extracted at fixed intervals (every 5 seconds) — a `frame` match's timestamps are anchored to that grid, not to the exact sub-second moment something appeared. `scene` segments are bounded by detected shot boundaries, which can be tighter than 5 seconds if the video cuts quickly, but aren't frame-perfect either.

In practice: treat a `frame` or `scene` timestamp as "within a few seconds of this point," not a frame-accurate cue. If your use case needs sub-second seeking, seek slightly before `timestamp_start` in your player rather than exactly to it.

## Transcript segments

`transcript` timestamps come from Whisper's speech segmentation, which is generally tighter — segment boundaries follow natural pauses in speech rather than a fixed grid. This makes transcript matches more reliable for "jump to exactly where this was said" than visual matches are for "jump to exactly where this appeared."

## Using timestamps to seek video

`video_url` is a presigned URL to the full video file, not a pre-clipped segment — append a fragment or use your player's API to seek to `timestamp_start`:

```html theme={null}
<video src="{video_url}#t={timestamp_start}"></video>
```

Most browsers respect the `#t=` media fragment for MP4. If you need a pre-trimmed clip rather than a seek point, you'll need to trim it client-side or in your own pipeline — Pureframe AI doesn't generate clip files.