After my pervious adventures with a Pioneer DVR recorder, a user contacted me and asked me if I could also analyze the Filesystem of a Panasonic DVR recorder and sent me an image.
I saw that it uses a custom Filesystem which is called MEIHDFS V2.0. I searched for this term on the Internet and found this thread. It seems that a guy called hkmaly started researching the filesystem and found out the block size. As he obviously already found out some of the structures, I thought that I should contact him and fortunately, he immediately responded to my inquiry. He was kind enough to send me the sourcecode he wrote back in 2012 when he researched the filesystem and found out the description of an inode block. However he didn’t find the inode directory and therefore only managed to collect inode blocks on disk where it was unvertain if they were sctive or inactie as the directory and inode blocks get rewritten after every editing process resulting in multiple copies of the same inode number on the disk making it impossible to recover the current state. Using a Hex editor, I finally found the inode directory and gathered enough information to be able to restore the filesystem of the recorder in case the inode table is always at a fixed position starting from the superblock (which I’m not sure but just assuming).
The recorder basically stores the DVD-Recordings in DVD-RAM format where there unfortunately is no description available, because it’s a proprietary standard. However I found the dvd-vr program where the author managed to gather lot of information from the format using reverse engineering. Using this as a template, I found out the structure of the Recorder’s .VOB files which are slightly different than the ones on DVD-RAM (mostly they are shorter omitting some stuff that the original DVD-RAM format has incorporated). So I created a modified copy of this program that was able to parse the Pioneer DVD-RAM format used.
So I finally ended up with 2 utilities: extract for extracting the MEIHDFS Filesystem und dvd-vr for extracting movie data from the resulting .VOB files.
Technical information about the filesystem and various other informations can be found in the README file of the project.
You can download the source and binaries >> HERE <<
Hopefully this is helpful for people with failed harddisks to recover their movies. I’d love to hear from you if you managed to rescue your data with it. If you have questions or need adaptions of the program for your recorder, feel free to contact me.
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