Forensic examination and analysis of digital media and systems is a significant resource in modern policing, forensics and the evidential support of prosecution cases.
Our client, a UK forensics agency, engaged us to develop plug-and-play decoding modules for an Open Source video playback framework, in order to extract digital video footage from a source data stream.
The clarity and accuracy of the decoded digital footage is critical, as it may be used as evidence in a court of law.
We worked in a technology partnering role with our client, providing them with an embedded software capability which fell outside their own field of specialisation.
First we needed to establish whether it was even possible to recover footage of the necessary quality from the source hard discs.
Prior to designing the plug-in modules for each codec, we reverse-engineered the source data and applied audio and video streaming manipulation techniques in order to establish that recovery of a video stream and suitable playback from the source hard disc was not only possible but also yielded the desired quality required for evidential support.
At this point we developed the plug-in modular tools and resources which handled the decoding of specific data and proprietary formats and allowed playback and frame-by-frame examination of the desired footage within the Open Source video playback framework.
They provided the higher efficiency and speed of searching and targeting which our client needed.
The development of the codecs required a detailed knowledge of C, Java, Linux, FFMPEG, image decoding and processing techniques, and MPEG 4 and H.264 file formats.
This was a challenging project, particularly with respect to the image decoding and processing, but with experience in these areas, and tenacity, our engineer was able to complete the reverse-engineering exercise which allowed the project work to proceed.
Our modules achieved a consistent decode and playback quality of the standard required for evidential support.
Analysis of a wider range of digital footage sources is now possible, and our client saves significant time acquiring the desired footage.