Video camera often use FAT to record data. When deleted, all details of any data fragments is lost.  Also, on some cameras, all information about the location data is stored in is also lost.  CnW have therefore created a special, dedicated function to scan the memory chip and recover all AVCHD video clips. Unlike many other recovery programs, it will produce a number of long clips rather than 100s of short clips that have to joined togther by hand.  The process allows for fragmented and deleted files.

The routine is designed for memory chips and so is only implemented for disks upto 128GB.

The program is a two stage process

• The chip is scanned for all MTS clusters
• The clusters are then sequenced into long data runs
• CPI files are receovered
• MPL files are recovered

Where CnW Recovery scores over other recovery programs is that it examines the whole memory chip first.  It logs the start and end of each cluster of video.  From this table it can build complete files, rather than just short fragments.  On one rweal life example 8GB memory chip, there were about 500 fragments, which competeing software produced as 500 MPL files.  CnW reconstructed the correct number of about 60 files.

Setup parameters

There are two important paramters that must be set correctly before starting.  The first is the sector start and cluster size.  For FAT chips these are often (but always) determined by the program. The start sector is an offset of the cluster on the disk, and is modulus the cluster size.

The time interval is the interval between frames of video.  Auto may be selected, or fixed values of 0x8D0 or 0x69C may be selected.  If the value is wrong, the symptom is many short files being found rather than 10s or 100s or reasonable sized files.  If none of the options work, please send some sample (short) .MTS files to CnW and a new value will be added.

How to view AVCHD files

AVCHD is a complex format that is a mix of MPL and CPI files.  All tne video is stored in MPL files, and these can be viewed through programs such as MediaPlayer - but only on Windows 7 (ie not XP).  CnW recovers files, but does not create valid file names, ie the MPL and CPI do not necessarilly tie up.  One suggested method of recovery is to copy the recovered, complete files back onto a memory chip, and get the video camera to re-index the files.  This should produce a memory chip in the format as it was before the files were deleted, or corrupted.