Pro workflow
.MDT file recovery: rescue footage after a camera power loss
Your camera lost power mid-take — cable tripped, battery died, body overheated — and instead of an MP4 there's a mysterious .mdt file on the card. Don't delete it and don't format the card: that file usually is your footage, one step away from being a video again.
What an .mdt file actually is
Cameras don't write a finished MP4 continuously. They stream encoded frames to the card and write the finalizing structures — the index, the container closure — when you press stop. Interrupt that (power loss on a Panasonic LUMIX GH-series body is the classic case) and the unfinalized data is left behind, often surfaced as an .mdt file. Inside is the real H.264/HEVC stream your sensor captured; what's missing is the container that makes players recognize it.
First, protect the card: stop recording to it, don't format it, and copy the .mdt file (and a healthy clip from the same session) to your computer before attempting anything.
Recovery steps, in order
- Let the camera try first. Reinsert the card into the same camera and power it on. Many bodies detect the unfinalized take and offer their own repair. If it works, you're done — this path is free and lossless.
- Copy everything to your PC. The .mdt file plus at least one healthy clip recorded with the same settings (resolution, frame rate, codec). That healthy clip matters — it's your reference.
- Rename a copy to .mp4 and test. Occasionally the file is closer to complete than expected. Try playing it in VLC and probing it with MediaInfo.
- Try an FFmpeg stream copy:
ffmpeg -i clip.mp4 -c copy fixed.mp4. If FFmpeg reports invalid data found, the index is missing — expected for a power-loss file. - Rebuild with the reference clip. The reference-file method reconstructs the container from your healthy clip's structure. This is the step that turns the .mdt data back into playable video.
For working videographers
If this was a client shoot — an interview, a ceremony, a one-time event — work only on copies and keep the original card untouched until you've verified the recovery. And going forward: dual-slot relay recording doesn't protect against power loss (both cards get unfinalized files), but a battery grip and locked power cables do.
Rebuild the container locally — client footage never leaves your machine
StreamSalvage repairs unfinalized recordings on your own PC using a reference clip from the same camera. Free preview of the result, $29 one-time, no upload — no client footage on third-party servers.
Download StreamSalvage for WindowsFrequently asked questions
What is an .mdt file on my camera's SD card?
It's the leftover of an interrupted recording. Cameras like Panasonic LUMIX models write video data to a temporary structure and finalize it into an MP4/MOV when recording stops. If power is lost first, the unfinalized data remains on the card — often with an .mdt extension — containing your actual footage without a playable container.
Can the camera itself recover an .mdt file?
Sometimes. Put the card back in the same camera and power it on — many models detect the unfinalized recording and offer to repair it. Try this before anything else; it's the manufacturer's own recovery path and it's free.
How do I recover an .mdt file on a PC?
Copy it off the card, then treat it as an unfinalized MP4: rename a copy to .mp4, try an FFmpeg stream copy, and if that fails use reference-file repair with a healthy clip from the same camera and settings. The raw frames are usually intact — they just need a rebuilt container.
Will I lose footage recovering an .mdt file?
Usually only the last few seconds before power was lost — frames still in the camera's buffer that never reached the card. Everything written before the interruption is typically recoverable.