The "LTC" watermark in blue might refer to "linear timecode" https://en.wikipedia.org/wiki/Linear_timecode https://en.wikipedia.org/wiki/Linear_timecode and I g

The "LTC" watermark in blue might refer to "linear timecode" https://en.wikipedia.org/wiki/Linear_timecode https://en.wikipedia.org/wiki/Linear_timecode and I guess it's possible whatever equipment they used to embed the timestamp in the video also adds this watermark.