Wednesday 4 April 2012

Forensic workstation pt 4

Earlier parts of this series had touched on identifying our needs and requirements from a workstation (see part 1), re-purposing an old PC into our first workstation (see part 2) and our early experiences of write-blockers and FTK Imager (see part 3)

Our experiments with our write-blockers have been limited, but each time we get them out of their boxes they seem a little less scary. The recent deposit of some born-digital audio and video material totalling over 200GB has thrown-up a number of new issues for us to consider.

The files came to us on an external hard drive formatted for a Mac that we needed to return to the depositor at which point we knew the files would be deleted - placing greater emphasis on the need to get the capture process correct as we wouldn't be able to return to the depositor and try again!

We were unable to browse the files in Windows Explorer, but were able to see the files using FTK Imager and our USB write-blocker. The sheer size of the files is something we are going to have to get used to with a 45 minute QuickTime film is 10.1GB and a 43 minute wav file is 671MB.

The workstation already has PaintShop Photo Pro for viewing and converting image files but only the standard viewers for audio and video content. So we started to look for open source software for viewing and converting the audio and film files, I wanted something that had a graphical and not a command line interface, as I was keen for other staff to develop skills and experience in handling this type of content.

As with our earlier use of tools like Karen's Directory Printer and DROID once we have become familiar with software we then document our use by creating a simple 'Idiots Guide' - this allows us to record both issues and solutions that we have encountered.

A bit of browsing and a few recommendations later and we have now installed Audacity v2 and WinFF but we will also take a look at others including Handbrake and FFmpeg before making a final decision.

We are keenly awaiting the forthcoming release of the DPC Technology Watch Report on 'Preserving Moving Pictures and Sound' and revisiting the FutureArch blog entries on media formats.