Add total size information to file format

[dbrant]

As long as the FLIF specification is still in progress, I thought I'd suggest an addition to the file format. As a specialist in data recovery and forensics, I'd like to be able to recover FLIF files easily from formatted or corrupted media. In order to recover a file (that isn't fragmented), we need two pieces of information: the starting location of the file, and its total size.

In the case of a FLIF file, we can detect its starting position easily, since it has a string of magic bytes in the header. However, it doesn't seem to be possible to get the total size of the file, without actually digging into the image data and decoding it, which would be overkill for a data recovery tool. It would be very useful, from a forensic standpoint, if we could have one of two things:

• Encode the total file size in the header of the file (as a 32- or 64-bit value, or a varint).
• Add a magic footer byte sequence that will uniquely identify the end of a FLIF file.