MP4 Video recovery and corrupt video
I recently did a MP4 video recovery from a memory card (SD). It contained combined JPEG photo and MP4 video data, shot with a Canon EOS 600 D. Previous recovery attempts done by the customer resulted in the majority of the files being corrupt. All MP4 video was unplayable. Most recovered MP4 videos were tiny files anyway.
Corrupt MP4 videos appear to be a common thing after data recovery.
- MP4 is a popular container format. So it is simply used a lot, in smart-phones, dash cams, GoPro like action cams and cameras.
- Also due to the nature of the format it becomes easily fragmented on FAT32 and exFAT formatted memory cards. Typically data is buffered, buffer is written to media, buffered etc.. Devices like GoPros even write a lower resolution and high resolution stream to the memory card simultaneously which also ‘promotes’ fragmentation.
Our telemetry (JPEG Recovery LAB) shows that 79% of all video files on memory cards is fragmented! And as mentioned plenty of times before in my blog posts, most undelete, photo and video recovery software can not handle fragmented files.
JPEG Recovery LAB can reconstruct fragmented MP4 video files while recovering them and has been successfully used on various types of dash-cams, consumer digital photo cameras and action cams like the popular GoPro.
MP4 Video Recovery or MP4 Repair?
There are many MP4 video repair software titles, guides and online services available. If those corrupt files are a result of data recovery, chances are they are recovered incorrectly in the first place.
This is due to the file system on most memory cards (FAT32 and exFAT): Once a file is deleted or lost due to formatting, the structure that contains the chain of clusters that make up the file (file allocation table) is reset. Thus, even if the undelete or video recovery software is able to determine the correct start cluster of the MP4 video (or any other file), it has to guess the rest of the clusters follows in a consecutive block. Quite often this is not the case.
Using MP4 repair software is quite moot in such a scenario. You may need JPEG Recovery LAB to carve the memory card for all video fragments.
MP4 not detected by JPEG Recovery LAB
If JPEG Recovery LAB fails to detect MP4 video files (like in my case) or files are corrupt after recovery, sent me an intact file shot with the same camera (preferably at least 1 minute duration).
In this case file was internally padded with zeros which JPEG Recovery LAB did not account for. After modifications JPEG Recovery LAB picks up the files, however no previewing is possible.
So, even if JPEG Recovery LAB is unable to play the MP4 video files or classifies them as damaged, still select and copy them.
After recovering the MP4 video files to the hard drive the default Windows player would not play the files. The program stating they were corrupt. VLC Player however does play the files without issues (https://www.videolan.org/vlc/index.nl.html). Also, the older but still included Windows Media Player can play the files without problems.
Tips and hints for MP4 video recovery using JPEG Recovery LAB
- Disable Preview on low memory systems (8 GB or less)
- Video recovery does fairly well with all other file types disabled
- Even if JPEG Recovery LAB is unable to play the video, recover the file anyway
- Also, even if it puts the file in the damaged directory, recover the file anyway
- Windows 10 Movies and TV sucks, use older media player or VLC