Guides Guide

Preserving CCTV footage correctly

Act before the recorder overwrites it: record the clock offset, export in native format and hash everything.

27 Sep 2026

Most DVR / NVR recorders overwrite footage after 7 to 30 days. Act quickly.

1. Before exporting

  • Photograph the recorder screen next to a phone showing the real time. This records the clock offset for the CCTV Time Corrector.
  • Note the recorder make and model, the channel / camera numbers and where each camera points.

2. Export

  • Export in the recorder's native format (e.g. .dav, .264) and, if available, in MP4. Native files keep original quality and metadata; MP4 is easier to review.
  • Export a few minutes before and after the incident.
  • Also export the player software the recorder offers, if any.

3. Integrity

  • Hash every exported file with the Hash Calculator and print the custody receipt.
  • Work only on copies.

4. Review

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