Sunday, August 2, 2015

Panasonic Lumix GH4 recovery

I have often written about recovery from video memory chips.  Everything I create a new solution, a new variation is found.  The latest one is from the Panasonic Lumix GH4 camera.

The video is fairly standard AVC  MP4 structure.  As is typical, the ftyp and moov are recorded in one section, while the mdat is in a different section.  In most cases these sections adjoin.  However, the Panasonic, in at least one case have split these sections to different areas of the memory chip.  This means there are series of ftyp-moov atoms, but after all ftyp-moov atoms, there are then a series of mdat atoms.  Each mdat starts on a cluster boundary so joining the correct moov with the correct mdat has involved analysing the header to see where frames start in the mdat.  Each mdat is then examined until a match is found.  A novel approach, but also one that normally means the atoms are saved sequentially.

The recovery routine has now been added to CnW V4.95

No comments:

Post a Comment