Use VLC Media Player , which handles almost all .mp4 codecs and allows you to take "Snapshots" of important frames.

If you are struggling to play the file or need to extract specific parts:

Watch the video through once and create a . Since the title suggests there are 13 segments (1-13), mark exactly where each segment starts and ends. 0:00 - 2:15: Segment 1 (Subject/Action) 2:15 - 5:40: Segment 2 (Subject/Action) 2. Contextual Identification

Right-click the file and select (Windows) or Get Info (Mac) to see:

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