Effects of content trimming iPhone 12 Pro Max video files in iOS 14.

In this audio/video authenticity research project, 44 original MOV files were produced on an Apple iPhone 12 Pro Max mobile device, running the iOS 14.2.1 operating system, in all available video formats and at four different nominal recording lengths. Each of the original files was then trimmed, using the Apple Photos app, in three different ways: deleting a portion of the beginning, a portion of the end, and portions of both the beginning and end. These 176 original and trimmed files were transferred to a laboratory computer and the footer and other metadata were analyzed with a hex editor. This analysis revealed that the trimmed recordings could be differentiated from the originals; that the iPhone model and the iOS operating system version could be identified; that important recording dates and times can be determined; and that the type of trimming, in some cases, could be determined. [ABSTRACT FROM AUTHOR]