Fix it now
- Drop the file
- Repair runs locally
- Download the result
The DJI FPV drone records onboard 4K up to 60 fps at bitrates up to 120 Mb/s, writing standard .MP4 files (H.264 or H.265/HEVC) to the microSD in the aircraft. That high-quality onboard clip is separate from the low-resolution feed cached in the goggles — the file you care about lives on the drone's card. An MP4 becomes playable only when the drone writes its moov index at the end of the recording; a crash or power loss cuts that write, leaving a file full of real footage with no map to it. Drop the clip above and the tool checks exactly that, in your browser, and rebuilds the container when the footage is recoverable.
Why a crash breaks the last clip specifically
An MP4 is written in two parts: the media payload (mdat) streams to the card frame by frame as you fly, and the index (moov) — the table that says where every frame lives and how the H.264/H.265 stream is configured — is written last, when recording stops cleanly. An FPV drone almost never stops cleanly when something goes wrong:
- Impact. FPV airframes fly fast and close; a clipped gate, a tree, or the ground stops the drone — and the write — instantly, mid-frame, before the
moovis stamped. - Power loss. A battery ejected on impact, a depleted pack, or a brownout during an aggressive maneuver cuts power the moment it happens, leaving the current file headless.
- A card that skipped a beat. A microSD too slow for 120 Mb/s, or one knocked in the crash, can truncate the recording.
The symptom is consistent: a file with a realistic size — often hundreds of megabytes — that a player rejects as corrupt, reports as 0:00 long, or opens to nothing. That size is the tell: the footage is there, only its map is missing. And because earlier clips from the same flight were finalized before the crash, they play fine — it's only the recording that was live at the moment of failure that ends up unplayable.
How the rebuild works — and why a good flight helps
When the moov is missing, it can be reconstructed by scanning the surviving mdat and rebuilding the sample tables the drone would have written on a clean stop. For a faithful result the rebuild needs the exact stream configuration — codec (H.264 vs HEVC), resolution, frame rate and the parameter sets — and the most reliable source of those is a healthy clip from the same DJI FPV recorded in the same mode. Because a crash usually leaves earlier clips on that very card intact, you typically have a perfect reference already. You'll only be asked for one if the file needs it.
Two honest caveats for a crashed drone. First, don't confuse the goggles' cached DVR footage with the onboard clip — the onboard MP4 on the drone's microSD is the full-quality file, and it's the one worth repairing. Second, if the aircraft went into water, mud, or a long tumble, check the microSD itself: a physically damaged card can return zeros for parts of the file, and no software can rebuild footage that was never actually saved. Copy the card to your computer first; if the bytes are there, the container rebuild does the rest.
What this can and can't fix
Can fix
- The clip that was recording at the moment of the crash or power loss (unfinalized MP4, missing moov)
- Onboard H.264 or H.265 .MP4 files that copied off the drone's card but won't play in any player
- Container damage: missing index, wrong offsets, zero-length duration, when the video data survived
- Files a recovery tool returned in an unplayable state, when the footage itself is intact
Can't fix
- Footage never written because power was cut before those frames reached the card
- Data physically lost to a microSD damaged in the crash (recover the card first, then repair)
- The goggles' low-resolution cached DVR clip, which is a separate, lower-quality recording
- Files that read as 0 bytes or mostly zeros
If a repair fails, we tell you why (missing data versus broken structure), and you are never charged for a failed repair.