Need help rescuing a corrupted MP4 file

[shira]

A family member asked for my help in rescuing a personal video in MP4 format which resides on a data CD. It's the only copy of the video available. The MP4 file appears to be corrupted.

Based on the fact that the primary symptoms involve Windows Explorer (I'm using Windows 7) being unable to copy the file to my hard disk (or upload it to Google Drive), I'm guessing that the corruption lies on the physical CD media rather than the video content. There are other files on the same CD which I can work with just fine, the only problem lies with this one particular file.

The file is 657 megabytes in size, and the corruption appears to be about 40 megabytes from the end; i.e., about 610 megabytes after the beginning of the file. I can view the video (the section of it before the corrupted part) in Windows Media Player just fine.

I'm thinking that maybe the best way to rescue this file is to use either video conversion software or file copy software that has the ability to save a partial file when it reaches the unreadable section. I can live with loss of the content in the final 40 megabytes if anyone can steer me to software that will let me save a partial file when it reaches the corrupted section. I'm ok with keeping it in MP4 format, though I'm also willing to look at converting it to a different format if I can do so with minimal data loss in the conversion process.

Any suggestions of tools that would work on Windows 7 and would let me copy/convert my corrupted MP4 to my hard disk and save the partial file when it reaches the problem area?

[redwudz]

Try ISOBuster.

You may also be able to open it with a hex editor, such as the one in Virtualdub and examine the damaged section to see if any data survives.
If it's all zeros, then there's nothing there and nothing to be done.

[shira]

Redwudz, thanks for your reply! So ISOBuster would work on a data CD? I thought it was intended for VCD's, which are a different animal.

My current version of VirtualDub is an old one, and doesn't support MP4's. Maybe I need to download the latest.

[TorBru]

The best (free) tool to recover corrupted files from bad drive or media should be TestDisk (and/or PhotoRec). If there is physical damage to the media it can be hard to recover whatever is located in the corrupted area, but the rest should be recoverable. When you successfully have recovered the damaged MP4 you can use a tool like ffmpeg to re-encode it. Even though re-encoding seems like devils speech in this forum you can often make a unplayable video playable by doing it anyway. Good luck

http://www.cgsecurity.org/wiki/TestDisk

[jagabo]

You should be able to use Explorer to copy the file but it may take a long time. Just keep answering "ignore" when it asks if you want to ignore the error, retry, or abort.