how to check if a video was modified

Everything seems to be syncronysed, however, what if they used a canvas to get in the scene, a canvas that has the same colour of the laminate floor, hiding under there belly down to get into the scene?what are the marks I should look for in such a long video?

Everything seems to be syncronysed, however, what if they used a canvas to get in the scene, a canvas that has the same colour of the laminate floor, hiding under there belly down to get into the scene?what are the marks I should look for in such a long video?

Motion detection?
https://forum.videolan.org/viewtopic.php?f=7&t=89563

I mean, the hypothetical "canvas" must be placed in front of the camera, and unless this is done in a flash (BTW additionally synchronized to the frequence of the frames taken) at least one frame should have captured that "unfolding or placing" in progress.

jaclaz

Thanks I am checking

I see right off the bat that tiny movements are not being captured as well as the clock which is in the image frame, the motion detection does not catch the clock in the picture but does catch the changing second minute hour in the timestamp clock

I see right off the bat that tiny movements are not being captured as well as the clock which is in the image frame, the motion detection does not catch the clock in the picture but does catch the changing second minute hour in the timestamp clock

Good. )
Now crop the whole video in such a way that the timestamp clock is removed (or superimpose a black square covering it) and re-process the result.

And/or try with another software, the given reference to VLC was just an example, there are many - if not better - more specific softwares, though most are Commercial.

jaclaz

sorry for the delayed reply. so far however no luck. I do not understand the meaning of your last suggestion, whatI should do

sorry for the delayed reply. so far however no luck. I do not understand the meaning of your last suggestion, whatI should do

I mean, let's say that now our video is 1024x768 and the superimposed date/time occupies 68 pixel at the bottom left.
If you crop
http//www.ghacks.net/2011/09/21/how-to-crop-videos-with-free-software/
the bottom 68 pixels and have a new video 1024x700, the superimposed date/time changes in timestamp won't be there and cannot affect the motion detection.

jaclaz

…
If you crop
http//www.ghacks.net/2011/09/21/how-to-crop-videos-with-free-software/
the bottom 68 pixels and have a new video 1024x700, the superimposed date/time changes in timestamp won't be there and cannot affect the motion detection.

jaclaz

ok, well the timestamp does not in fact affect the motion detection, I do not think so at least. I was only saying that you can see that the changing second in the video timestamp is detected as movement but the digital clock which is filmed in the video is not detected as movement when the minute changes. As well small movements are not being detected but if an object get moved in the scene, that does get detected. So far I do not see much however the video sometimes changes light and flickers. I do not know if to take note of those changes as they are pretty common.

Well, this is NOT what you posted earlier

I see right off the bat that tiny movements are not being captured as well as the clock which is in the image frame, the motion detection does not catch the clock in the picture but does catch the changing second minute hour in the timestamp clock

but anyway, the idea is only to reduce the "long hours" of looking at the videos to "less hours", centered around what the motion detection software finds, and not necessarily it is "foolproof".

jaclaz

Ok I must try and concentrate on the events that are triggered by motion detection to see if something is wrong. I was thinking however. What if the pc was being completely hacked?
What if the video recording software was saving the file in an invisible folder and the video that I see is instead something which is being edited somewhere else?