Corrupt File on SDHC

[Terrence Cook]

I recently shot some HD video on a small SDHC camera, I successfully captured 20 or more minutes of video... but in the heat of the moment I turned off the camera before I stopped recording. So, every single file I have filmed with this thing previously is flawless, but the one clip that matters!!

So... I am pretty sure a lot of the video is there because the clip is 3.6GB. But I am completely unfamiliar with how to go about retrieving any of this data.

Any advice for specific software or methods?

Thank you.

 

[Darren Addy]

Make and capacity of card, please?

Also, do you have a USB card reader or do you just use the cable to connect camera to computer?

What type of files are saved to the card (.avi .mov etc.)?

 

[Terrence Cook]

Delkin 16GB Class 6 22mb/s

Built in SD slot and a cable to the camera.

.MP4 (Video)

 

[Darren Addy]

Well, this isn't going to be very encouraging. As you may know, the file footer of an mp4 file that are written at the END of the process are critically important. So theoretically, if you can get the file off the card you could use a hex editor to paste the footer from another (uncorrupted) video onto the end. Searching for this info, you'll find some people call the footer the "header" in this case.

In practice, people seem to have had very limited success with this approach and even those have recovered video only (no audio). I haven't found info on the mp4 header format yet (and it may vary slightly between manufacturers) but since it is written at the end it probably contains information that is particular to the file that comes before it (perhaps exact frame count, quality settings, etc.). So taking a header from another file would be like pasting an index from another book. It looks like a complete book, but try to use the index to find what you are looking for and you'll see it is a little more complex than that.

If I find anything more definitive I'll post it, but even a hex editor solution would not be for the faint of heart.

If nothing else, I guess this taught me something about the value of video tape over digital.