Now this is a very simple check and will mainly tell if a file is not intact.Īt least, that's the theory, because I'va ran into playable mp4 files that start with an mdat atom. Usually an mp4 starts with the ftyp atom so I know of some recovery tools that check if a mp4 file it detected using the MFT is intact or not by verifying it starts with the ftyp atom. Core component is the 'atom', common atoms are ftyp, mdat and moov and often these atoms appear in this order. If we consider a file type like mp4, we're dealing with a standard that offers a lot of 'freedom'. However this image will 'render' just fine and is thus harder to detect as beng corrupt: This could be easily detected using code. This bit happens to disrupt the decoder resulting in half the image disappearing. To check actual data of a JPEG file the validation tool needs to either look at the JPEG encoded data and see if it appears valid, or it needs to look at the actual image and determine if it looks okay.Ī JPEG can become corrupt due to one bit in the encoded data 'flipping' which I demonstrate here: Chkdsk checks if a file system is okay or consistent but it has no idea about the actual data. So sort of how chkdsk looks at the file system. Now, if we'd zoom into one file type, for instance JPEG, it is not rocket science to write some code that checks if the file is structurally okay. So for a tool to support 20 file types is like writing a file recovery tool with support for 20 file systems. ![]() corrupt/invalid files it would need to understand each file type it supports in detail. ![]() For any software to detect healthy/valid vs. Many file types are actually pretty complex, sort of mini-file systems in themselves. Note that this is not a software recommendation question - I'm specifically asking in SU instead of Software Recs because I don't want to limit the question from possible non-software solutions, including scripting, native command-line, and so on. What solutions are currently out there to allow me to search for corrupted files and remove them from my recovered hard-drives? For obvious reasons, I'd rather not have to do this. This is easier on image file formats, for which the lack of a thumbnail is a giveaway that a file is corrupted, but for most other formats, like audio and video files, the files would need to be opened and played all the way through to determine there is no corruption. These files consist of all of the major file formats: images, video/audio files, Word documents, PDFs and so on, and what I'm currently facing is going through each recovered folder and manually opening up each file to determine whether it's corrupted or not. ![]() Most of the recovered data is intact, but amidst a total of 3TB of data, even a small percentage of corrupted files adds up to large figures. I've recently recovered a few hard-drives using partition and data recovery software.
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