Monday, September 16, 2013

GoPro Hero 3 recovery of deleted files

I have often said of data structures, 'if it can be done, it will be done'.  ie almost anything is possible, and so expect many variations.  In the words of the 'Hitch Hikers Guide to the Universe' - Expect the unexpected.

A recent view of a GoPro Hero 3 camera confirmed the above.  As I have written in the past, video camera often record the data not in a different physical to logical sequence.  The slight of hand is that the FAT defines the logical sequence.  Thus many camera record the video data physically earlier than the file start sector.  On the GoPro Hero 3 camera another twist has been discovered.  Two video streams can be recorded at the same time - a high resolution, and a smaller low resolution.  The physical sequence on the disk could be as below

Just to complicate the above, there can also be jpeg thumbnails, and text status files inserted in the above stream.  Standard data carving is totally useless as nothing is in sequence.

The CnW MP4/3GP Wizard works hard, but will recover, with a high success rate videos that have been deleted.

Tuesday, September 3, 2013

Windows 8

It was time for a new PC and so Windows 8 - 64 seems the obvious option in order to keep up to date.  I ordered reasonable spec system (3.6GHz, Core 7, 12GB RAM) and a week or so later it arrived.

I have had Windows 8-32 since it came out, but not as a main PC.  This post will describe some of the issues I've had, and some solutions.

My work (data recovery) requires lots of disk space.  I keep the main 2TB system drive as the system and development drive.  All customer data is stored on other drives - or a new 9TB NAS RAID.  My first job was to add a second 3TB drive to the PC.  This was a reasonable quick job with the screwdriver, and the drive was seen in the BIOS.  However, what ever I did, I could not see it in Windows 8.  Google to the rescue and it turns out that Windows 8, being much more secure will not recognise extra hardware (though it could see USB drives).  The solution was a BIOS option switch to remove the 'Secure boot' option.  Drive now seen, and the secure boot can now be re-enabled.

The next problem was Norton antivirus.  The PC came with McAfee, but the rest of my systems all have Norton, on a group licence.  I uninstall McAfee and installed Norton 360 but then problems began.  Various problems, mainly IE10 and other internet related products had issues.  Worse still, each time I rebooted the PC, Norton stopped working and often came up with the error 8504,101.  Google had several ideas for this, including running NPE.exe, uninstall and re-install.  I tried many of these suggestions, but none worked.  The error message is common on Google posts, and so I installed AVG and started to get some work done.  Even the Beta version of N360 had the same problem.

On hardware, I have become a complete fan of multiple screens.  The new PC has 3 video outputs,  but 2 of them are HDMI, and I only have (old) VGA screens.  I hope the eBay adaptor will arrive soon and let me work with 2, or maybe 3 screens at once.

A final issue I had was over a security dongle.  The drive is not signed, and so Windows 8 will not load it.  The solution was the result of another search and involves booting Windows in a mode to accept unsigned drivers.  The instructions (with due credit to someone else) are as follows

1. Windows Key + R
2. Enter shutdown.exe /r /o /f /t 00
3. Click the OK button
System reboots here

4. System will restart to a Choose an option screen
5. Select Troubleshoot from Choose an option screen
6. Select Advanced options from Troubleshoot screen
7. Select Windows Startup Settings from Advanced options screen
8. Click Restart button
9. System will restart to Advanced Boot Options screen
10. Select Disable Driver Signature Enforcement
11. Once the system starts, install the drivers as normal


Looking forward to Windows 8.1 where I hope the metro screen will be less important, though I will start playing with some of the apps.