I used to work for a company who made verifiable audio and video for law enforcement. Even a constant running timecode could be circumvented in the early 90's.

I used to work for a company who made verifiable audio and video for law enforcement. Even a constant running timecode could be circumvented in the early 90's. (They used to use a dedicated audio channel to encode a hash of the last few seconds - on analogue). It actually takes a lot of effort to show that a video hasn't been/could not have been doctored.