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-   -   how to clone a p2 card (https://www.dvinfo.net/forum/panasonic-p2hd-dvcpro-hd-camcorders/106257-how-clone-p2-card.html)

Dan Kelly October 22nd, 2007 11:18 PM

how to clone a p2 card
 
Hi all,

Does anyone know if there's been a breakthrough on recovering data from an accidentally formatted (in camera) p2 card?

If not, I'd like to know if there's a way to make a clone of a 16gb p2 card and retain all data as is, thus maximize my chance of file recovery in the future. I'm mac based, can anyone recommend specific software that they've actually used to do this? I've read other threads on this but none of them mention specifically what software they used to copy the entire card in a way that corresponds to a "block level" hard drive clone.

I've tried using disk utility to make a disk image, but for a formatted p2 card (previously full before being formatted) the size of the disk image is way < 16 gb.

Much thanks,

Dan

Kaku Ito October 23rd, 2007 07:59 AM

Man, Dan, I feel you.
PC utilities might have better chances, maybe?

Dan Keaton October 23rd, 2007 06:42 PM

May I suggest that you contact Panasonic?

For other flash based devices, such as high-end SanDisk flash memory cards, there is some "Rescue Software" which will recover deleted files.

Their used to be, software, that unformated a hard disk. It was not an easy processed, but it could be done.

I have not done any of the above with a P2 card.

Panasonic may have some software to assist.

Whatever you do, do not write anything else to the card. If you do, this will guarantee that you will not recover your data.

At last resort, I would try the "Rescue Pro Plus" or similar sofware designed for the SanDisk cards with your P2 card. I have no idea if it would work or not, but remember, this is a last resort.

Dan Keaton October 24th, 2007 06:31 AM

If you have a second P2 Card,
record something on it,
then format it,
then attempt to use whatever techniques you are considering to use on the P2 card that actually was formatted prematurely.

In other words, practice your recovery techniques on another P2 card.

If you find a technique that works, use it on your P2 card that was formatted.

TingSern Wong November 4th, 2007 07:02 AM

As I understand, the P2 firmware (RAID controller) inside the card actually wipes out the (zeroises) the FAT table when you format the P2 card. The data is still there, but, with the FAT table all zero, there is no way to tell which sector of the data belongs to what file - therefore, I have doubts you can recover any data from a formatted P2 card.

Dan Keaton November 4th, 2007 07:56 AM

Dear TingSern,

Yes, it makes it more difficult if the FAT is zeroed out.

In certain certain computer operating systems, instead of zeroing out the FAT, they write a special character over the first character of the filename in the FAT (File Allocation Table). This is a quick and easy procedure and it allows an "UnFormat" function.

Lets assume that the FAT is completely zeroed out, the worse case scenario.

It so, then file recovery software could set up one FAT entry which points to the very first sector (data block) on the P2 Card, and the length of the file could be set to the maximum length, the length of the card.

(To be a little more precise, depending on the sector size and the maximum size of one file, it may be necssary to setup more than one FAT entry.)

In either case, the data is probably still on the P2 Card, and a low level read of the data sectors, starting with the first sector and continuing to the last may recover all of the data)

Once the entire contents of the P2 card are read as one file and then saved on a computer disk (captured) then, the user would have to split the takes as required.



For discussion, lets say that the P2 Card was formatted prior to the shooting day.

If so, then all of the takes (shots) would be in sequence, as stored on the P2 card. This, however would not be true, if any takes were deleted during the shoot, unless the take deleted was the last take shot.

The theory behind this is that any deleted areas will be overwritten, until the card is full. Deleted areas will not be at the end, unless it was the last take just shot.

So:

1. If there were no take deletions,
2. Or if there were, they were the takes just shot,
3. Then the takes on the P2 Card would be in proper time sequence.


Disclaimer:

I have extensive experience working with File Allocation Tables, designing software, such as disk defragmenters.

However, I have not worked with the P2 card, so all of the above is just theory. It is true that many computer systems share the same root designs and are built on the success of other systems.

TingSern Wong November 4th, 2007 08:40 AM

Dear Dan,

While doing a low level sector by sector read of the P2 Card (treat it like a hard-disk) is indeed possible, thereby reading every byte of data out, the hard part is to identify the various files inside the P2 card. There are quite a number of files that make up the P2 system ... MXF, BMP, XML, TXT. All these files must be correctly co-related to each other. I have doubts that even if you have successfully pulled out all the data inside one huge file, the enduser will be able to fit the jigsaw puzzle together.

There are specialised software to recover image files from digital cameras. They do a good job. And there are specialised software to recover data from DVD / CD as well.

If someone could write one to recover P2 data, I am sure that there will be more than one willing buyer here on this net. Presumably, the cost of the software will be more than offset the cost of losing the video clips in the first place.

Dan Keaton November 4th, 2007 08:49 AM

Dear TingSern,

Yes, multiple file types for each take does complicate matters.

I agree completely, it would be nice to have such a data recovery tool.

It appears to me, that with the various file types that exist, that they are usually in a specific order, making the job just a little easier.

TingSern Wong November 4th, 2007 08:59 AM

Dear Dan,

While the files are indeed in a logical sequence, they may not be in physically adjacent sectors. So, how do you try to identify a MXF file that is AUDIO from the MXF file that is VIDEO? The BMP files are small image data. And the XML files are just text.

So - the hard part is trying to figure out the AUDIO MXF from VIDEO MXF. Just browse the data on my P2 - I can't see any identification within the data that says "AUDIO" or "VIDEO".

TS

Dan Keaton November 4th, 2007 10:55 AM

Dear TingSern,

I have just briefly read up on MXF.

If I was attempting a project to recover the data, I would first transfer all of the sectors to another disk.

Then I would search for patterns. Text would be fairly easy to find as it would be in ASCII and the data would normally be letters and numbers, a small set of the 256 characters available.

I would take a known good P2 Card, full of data (and not formatted to erase the FAT.

Then, I would attempt to determine any characteristics of the files.

A test play of a given sector as an audio file would show if it was audio or not.

Test playing of a video file may be much more difficult.

I hope I am clear, I am not attempting to say the project would be easy.


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