DiskDrill recovered a video — but it won't open. Why?

You formatted an SD card by accident. Or the card suddenly showed up as “unused” and the system wanted to format it. You ran DiskDrill over it, and back came a folder with a hundred files: file000001.MP4, file000002.MP4, …

And now: not a single one of them will open.

This article explains why DiskDrill produces files like this and what you can actually do about it now — based on a real case I (Thomas) went through myself with a Sony FX3.

What DiskDrill really does

DiskDrill (just like PhotoRec, Recuva, R-Studio) does carving: it scans every sector of the SD card for file signatures — for example the ASCII bytes “ftyp” for an MP4 file. When it finds one, it reads on until it sees the next ftyp start or recognizes a logical endpoint, and saves everything in between as a “recovered” file.

The problem: on an SD card, the bytes of an MP4 file don’t necessarily sit together in one piece. Once a card has been filled and emptied a few times, the filesystem fragments. An original MP4 file can be spread across 50 scattered sectors. DiskDrill sees the start (ftyp), but then reads linearly until the next signature — pulling in bytes from other, long-deleted files along the way.

The result: the “recovered” file is partly your original MP4, partly junk or fragments of unrelated files.

Two damage patterns that show up almost every time

In every DiskDrill recovery I’ve seen, the same two problems come up:

Damage pattern A: moov atom missing

Same as any interrupted recording — DiskDrill couldn’t find the index at the end of the file, or it sits in a sector that wasn’t captured. The file has ftyp + mdat (often with zero-padding at the start), but no moov index.

See moov atom missing — guide for the generic fix.

Damage pattern B: uuid header mixed up

This one is DiskDrill-specific and sneaky. On Sony XAVC, Canon Cinema, DJI and a few other cameras, critical codec parameters live in the uuid box at the start of the file:

• Profile (e.g. Sony XAVC-I High 4:2:2 10-bit Profile 122 Level 5.1)
• Bitrate class (e.g. Sony Class 240 vs. Class 480)
• Color primaries and transfer function (BT.709, BT.2020, S-Log3, etc.)

When DiskDrill reads from the wrong sector, these bytes can come from a different file — say a 25p Class 240 file that had long been deleted.

A concrete example from my FX3 case: file000328.MP4 showed byte 7A 10 33 at offset 0x6e in the uuid box. That corresponds to Profile 122 Level 5.1 = 25p Class 240. But with a C2221.MP4 as reference (also 25p Class 240), untrunc only produced junk frames.

Only after three attempts and cross-checking the mdat frame structures did it become clear: the actual file was 50p Class 480 (7A 10 34), and the uuid header had been mixed in from a neighboring sector. With C2297.MP4 (50p Class 480) as reference, the repair worked immediately.

Lesson learned: on DiskDrill-recovered files, the uuid header can’t be trusted. You have to verify the frame rate from the mdat itself.

How to spot uuid damage

If untrunc or a repair tool produces a “recovered” video with any of the following problems, the uuid header is probably wrong:

• Picture is garbage, audio plays (or the other way around)
• Wrong frame rate (25 instead of 50, or vice versa — noticeable as unnaturally fast/slow motion)
• Color mapping is flat (HDR material looks like SDR)
• Picture cuts off abruptly after a few seconds

If any of these show up, try a different reference — a recording with a different bitrate class or frame rate.

Step by step: repairing a DiskDrill-recovered MP4

1. Sort the recovered files

DiskDrill typically spits out 100–500 files at once, many of them duplicates or empty fragments. A quick sort by size lets you isolate the valuable ones — anything under ~50 MB is probably a junk fragment.

2. Try several references

If you’re not 100% sure what settings the original recording used, gather 2–3 different intact recordings from the same camera in different settings (25p/50p, Class 240/480, S-Log3/Normal). Try the repair with all of them — the right match is the one where the result plays cleanly.

3. Use a tool with a verification preview

This is the decisive point. Never buy a repair blind — you need to see whether the result is correct. With Haven you see the finished video in a preview before you pay. If the reference doesn’t fit, you see it right away and can try the next one.

4. On audio drift: don’t give up

DiskDrill-recovered files almost always have audio drift after the container repair — sometimes 1000ms or more. Tools like untrunc hand that over without correction. Haven measures the drift automatically and shifts the audio track back frame-accurately.

More on this: Fixing audio drift in video

Device-specific guides for DiskDrill recovery

Depending on the camera, there are specific quirks:

• Sony FX3 after a card crash — uuid header tricks, MEDIAPRO structure
• GoPro crash on the slope — saving the recording — different problems, because GoPro doesn’t write a uuid with profile info
• Repairing Sony recordings — full Sony strategy

What professional data recovery does differently

If you’ve lost extremely important footage and DiskDrill can’t get any further, there are hardware forensics labs (Kroll Ontrack, Stellar Data Recovery Services, Aeroquartet Treasured). They do the following:

1. Read the card under a microscope or with a professional reader (no file carving, but a raw image)
2. Filesystem reconstruction (rebuilding FAT tables, analyzing allocation patterns)
3. Manual file repair, sector by sector

This typically costs 500–2000 EUR and takes 1–4 weeks. Worth it only if the footage has value on that order (a wedding, a commercial shoot).

For everything else: Haven + a reference handles 80%+ of DiskDrill-recovered files, and you see the result before you pay.

Get a recovered MP4 checked →