What kind of file do you have?
| Extension | What it is | Can the checker repair it? |
|---|---|---|
.avi | A standard container, often Motion-JPEG or H.264 video with PCM or ADPCM sound | Yes |
.mp4, .mov | A standard container, H.264 or H.265 | Yes |
.dav | Dahua's own format | No; use Dahua's player or converter first |
.264, .h264, .h265 | A raw video stream, no container | No |
.asf, .mkv, .ts, .ps | Other containers | Not yet |
If the export tool offers AVI or MP4, export again in that format: a clean export from the recorder beats any repair.
When an AVI or MP4 won't play
The usual causes are a power cut while the recorder was writing, a USB stick removed before the export finished, or a card pulled from a camera mid-recording. The footage up to that moment is in the file; the index that tells a player where it is never got written.
- Copy the file to your computer.
- Open it in the checker on this page. It reads the file in your browser and uploads nothing, which matters for footage of people and places.
- The free check tells you whether it found the pictures and sound. For AVI, it rebuilds the index from the file's own frame headers.
- Watch the free 15-second preview, then download the full video for $4.99, or with a plan. If it doesn't play, write to support@nasrtech.dev and we'll look at it with you.
The Video Repair program for Windows does the same offline and handles folders of clips with the Technician licence, for installers and repair shops.
What we have tested
Dash-cam MP4 files from 70mai and Tesla came back with every frame identical, and since 29 October 2026 the engine also reads dash-cam MP4 files that carry MP3 sound. AVI repair in the Windows program was fixed on 16 October 2026 (version 1.0.2). We haven't had a file from a security DVR or NVR to test yet, so the free check and preview are the test for yours.
