Forensic Video Conversion & Analysis Expert Overview

To help ensure that camera footage is accurate and complete, it may be necessary to analyze the file(s) through a forensically sound process. Video evidence comes in many formats, and the footage may not always be reliable or complete when viewed on certain players. In this article, Chad Phillips from our Technical Services group discusses some of the challenges associated with video evidence and the correct methods for preparing videos for analysis or demonstratives.

The Problem with Some Raw Video Formats

Manufacturers of video surveillance systems often store the digital data captured by their cameras in proprietary formats. These proprietary formats generally require the use of the manufacturer’s own proprietary playback software, often referred to as a player. While these proprietary players allow for playback of the video, the visual presentation of the footage may not be accurate or reliable for analysis. 

Known issues with proprietary players include showing incorrect colors, frame rates, and aspect ratios. Other issues include using the incorrect pixel interpolation which may make objects appear larger or smaller due to adding or subtracting information in the video.  

Proprietary players may even make critical frames go missing. Failure to address these potential shortcomings may result in incorrect or unreliable conclusions.

Video Conversion

When required, forensically sound software can be used to convert and repackage video files into more accessible, lossless formats that can be reliably played on most commonly available media player software. Video conversion should be performed using a scientifically repeatable process that can be verified using comparisons of the video frame hash (a digital fingerprint) between the original and converted files.

Following acceptable forensic processes gives reasonable assurance that digital evidence was not corrupted or destroyed during the investigative processes whether intentionally or by accident.

Analysis and Enhancement

In addition to converting video, the Technical Services group at Robson Forensic can analyze, interrogate, and enhance video directly from the proprietary format using specialized forensic software. This approach allows experts in video analysis to reliably determine frame rate and native aspect ratio, identify missing frames, and correct for color distortion.

• Frame Rate – In most instances, frame rate reports can be generated to show best estimate frame rates which can be crucial for understanding the completeness of the footage and analyze object movement speeds. 
• Aspect Ratio – Issues with aspect ratio can distort the perceived size and proportions of objects. Video analysis can identify the native aspect ratio and match display to remove/reduce distortion to allow for accurate analysis. 
• Missing Frames – When using proprietary players, critical frames of data may not be played back.  It is not until the video is analyzed using forensically sound software that missing data can be identified and made visible.  
• Color Correction – To provide for better analysis, video may be brightened, colors changed, or contrast adjusted to enhance the visibility of the captured data 

Preparing Video Demonstratives

The Technical Services group at Robson Forensic can assist in parsing videos into individual frames to be exported as picture files. We regularly apply circles or highlights to draw viewer attention to points of interest or track objects through a duration of footage. Slow motion or fast forward treatments can also be applied to emphasize critical portions of the video.

Demonstrative evidence prepared from video should be produced to ensure it reliably, accurately, and clearly represents the captured footage and articulates any enhancements. Particular attention should be given so that video demonstratives emphasize critical facts without manipulating or misleading the triers of fact. 

Expert Retention May Not Be Required

Our services for video conversion, analysis, interrogation and enhancement, and the preparation of demonstratives do not always require the retention of a Robson Forensic expert. However, when advantageous to our clients, we can draw on the expertise of in-house experts in the development of visual aids. A thorough conflict check will be performed at the onset of any new project.

Submit an inquiry or call us at 800.813.6736 to discuss your project.

Featured Expert

Chad Phillips, AP

Technical Services Expert

Chad Phillips is an Aviation and Mechanical expert with over 15 years of professional experience inspecting, maintaining, and repairing helicopters, airport equipment, and a broad range of industrial… read more.