home home Staff Contact
Forensic Protection - Services Forensic Protection - Rates Forensic Protection - FP_System Forensic Protection - Process
Trade article

OPEN-SOURCE SOFTWARE FOR THE FORENSIC VIDEO ANALYST

The marketing of commercial software is funded by the paying public. These programs typically offer ease-of-use and extensive feature sets. However, no single software can be the “magic bullet” to address the vast needs of a Forensic Video Analyst. Unfortunately, the procurement of every forensic software tool is outside the budget of most labs. Furthermore, most commercial applications simplify (aka restrict) software feature options and behavior.

If you have ever used the Firefox web browser or Thunderbird email, then you already know the value of open-source software. Most open-source software is written by experts for the greater good without any advertising, fee or bloated code. AvsPmod, AviSynth and VirtualDub are three such open-source programs reviewed, improved and supported by millions of active users. These innovative tools let the user easily create, configure, reorder and customize thousands of free plug-in filters, scripts and features to clean video files.

Because these open-source programs are free, their power and flexibility are rarely promoted. This is not to say that open-source is a better resource than industry specific commercial software, but it does allow access to features unavailable in commercial applications. For example, Forensic Protection’s work on the George Zimmerman case was performed using open-source software and the resulting video-image evidence remains the clearest available anywhere. Those results would have been impossible using commercial industry software. A properly equipped forensic lab should rely on both commercial and open-source software.

OPEN SOURCE CAPABILITIES:
Directly open image-video files or use high-resolution screen capture with audio synch
Isolate camera views (even sequenced). Remove any borders and redundant frames
Stabilize cell phone & dash-cam video, isolate subtle motion, and track moving objects
De-interlace or field shift videos. Stitch multiple cameras into a single panoramic view
Brighten dark scenes, suppress video noise, zoom-in, crop and adjust playing speed
Correct for focus, motion and blur. Adjust curves, levels, channels and color space
Recalibrate viewing perspective to accurately measure an object’s size or speed
Authenticate a file's structure, watermark, metadata, error level analysis and hash tag
Analyze spectral, histogram and Fourier views. Work with “i” frames and vectors
Enhance audio and add on-screen transcription. Watermark clarified-enhanced files
View original and processed videos side-by-side, and save using common formats

Nearly everything required is free, with most optional capabilities selling for around $30. Each file and workflow detail is automatically documented for easy court-ready report generation. No other FVA solution delivers this level of power, control and access to the source code for full compliance with current and upcoming forensic guidelines.

AvsPmod and VirtualDub do not require installation and can be carried on a tiny USB thumb drive. As with AviSynth, these programs are free, open-source, and provide you with the unrestricted rights to use, rewrite and customize the software to meet your specific needs.

EDIT: All of the above open-source software has been combined into one easy-to-use program called VideoCleaner. As expected, the software plus any updates and support, are FREE. VideoCleaner is free video enhancement software.

When you launch AvsPmod you will see both a text and video preview window (press the F5 key if you do not already see the video preview window). As you begin to type a command into the text window, context aware help provides real-time guidance. If you type something that doesn’t make sense, a pop-up message will detail the problem. If you need further assistance, the built-in help or an Internet search can provide tremendous self-guidance.
You can also ask other forensic experts by posting your question at Linkedin’s AVIs group “Audio Video Innovations and Solutions”*.

INSTRUCTIONS:
In AvsPmod, use the right and left arrow keys to view the next or prior video frame. Use CTRL-B to add or remove a video frame bookmark, and then use F2 to instantly advance to the next bookmarked frame. Use the HOME and END keys to mark video sections that you wish to retain or delete. Use the numeric "+" and "-" keys to zoom in or out of the video.

Standard Windows shortcut keys are also supported. Use CTRL-H to find or replace text and CTRL-C to copy any highlighted text (use CTRL-V to paste that text). Begin any line with the pound symbol (#) followed by the tilde symbol (~) to enter your notes that, like every other command, becomes part of the automatic file documenting your process. Important details are recorded, and your workflow sequences can be easily reused and modified as needed.

Use the F12 key to add visual controls with definable parameters to any filter. The SHIFT-F12 key adds section titles and CTRL-T adds an on/off switch to any filter. Use CTRL-SHIFT-UP to move any filter upward in priority and CTRL-SHIFT-DOWN to move it down. Session tabs make it easy to compare different filter combinations and every change automatically updates the preview window. The user can easily customize any shortcut or program feature.

EDIT (11/19/2013): VideoCleaner is free video enhancement software designed to simplify the use of the open source software detailed above.

SUMMARY:
These powerful open-source tools deliver clear evidence and a greater understanding of how and why each process works. The user can optimize and automate nearly every step, thus eliminating judgment-based errors and ensuring an accurate reproducible set of facts. When used along with commercial offerings, the end result is optimal clarity with lower labor costs.

*NOTE:
AVIs is a fully-moderated collaborative group serving the needs of the forensic community. Topics include best practices, product support, industry standards, training resources, career opportunities, and a sub-group for vendor content. Postings are private and will not be indexed by the internet search engines. Free Linkedin membership is required.

Douglas Carner
has contributed to, but has no financial stake in, the promotion and continued development of open-source software to serve the audio-video forensic community.

Copyright © Forensic Protection
QuickLinks | Main page | Case study | Media | FAQs | Contact us