Recovery of AVCHD files is not always a case of straight data carving. Programs such as Stellar just look for file starts, and hence produce many short fragments.
CnW Recovery analyses the complete memory chip and joins together the correct fragments. On one true example, Stellar found about 500 fragements, while CnW produce 56 long files, correctly joined together.
Many AVCHD files are fragmented when generated with sections such as the CPI files physically located in the middle of a .MTS files. CnW Recovery takes care of this. A deleted FAT32 chip loses all fragementation information, hence intelligence is required for recovery.
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