Corrupted or Deleted Video from a Memory Card
Video files from cameras and drones fail in a couple of very specific, very common ways that photo and document recovery mostly doesn't run into — and the fix usually depends on recognizing which of those it actually is.
What's actually happening
Two distinct failure patterns show up constantly here. The first is deletion or card corruption, which behaves like the general cases elsewhere in this catalog — the file's directory entry is gone or the card's file system is confused, but the underlying data is usually intact. The second, specific to video, is the file that exists but won't play or shows as zero bytes: many video formats (MOV, MP4) write their index — the header data describing how the file's audio and video streams fit together — only at the very end of recording. If recording is interrupted by the battery dying, the card being pulled, or the card filling up mid-shot, that final index never gets written, leaving a file that's full of valid video data but has no map telling any player how to read it.
How recoverable this really is
Often good in both cases, but they call for different tools. Straightforward deletion or corruption responds to the same signature-based recovery used for any other file type. A file with a missing index, on the other hand, isn't actually missing data — it needs its index rebuilt from the raw audio and video stream, which is a distinct, format-specific repair rather than a recovery in the usual sense, and generic file-recovery tools that only look for a valid header often skip right past these files or reconstruct them as unplayable fragments.
The general approach
For straightforward deletion, standard recovery scanning works the same way it does for any other file type. For files with a missing or damaged index, dedicated video-repair tools analyze the raw stream structure directly, sometimes using a known-good reference file from the same camera model to correctly rebuild the missing header — a step generic recovery software typically doesn't attempt at all.
Stop recording and remove the card as soon as something looks wrong, rather than continuing to shoot on it "since it still seems to work." Every additional write, including the camera automatically re-indexing or attempting to repair the card itself, is a chance to overwrite the very data a proper recovery would need.
Practical, step-by-step guides for specific recovery software will be added here as separate linked articles.
This page describes the general situation, not a guaranteed fix for your specific case. If you'd rather have someone experienced take a look before you try anything, see what a hands-on evaluation looks like.