how to fast scan video files for a change in image

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swarmcatcher
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how to fast scan video files for a change in image

Postby swarmcatcher » 07 Feb 2019 21:33

Is there any way of scanning thru video files looking for changes in image.
The reason i ask is that i use a PTZ video in roof spaces to monitor for rodent and bird activity to assist in preventing the return of them.
This camera is linked to my computer and the video is recorded 24/7 - but there is no joy at all in watching nothing happening for most of the time.
ideally i would like to book mark them so i can scan to them quickly if its at all possible.

i have found the motion detection useful in that it highlights an eye of a rodent that i would otherwise miss but i still have to plough thru all the video.

Any advise would be gratefully recieved :D :D :D

Jean-Baptiste Kempf
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Re: how to fast scan video files for a change in image

Postby Jean-Baptiste Kempf » 17 Feb 2019 23:03

I don't think there is any easy way
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swarmcatcher
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Re: how to fast scan video files for a change in image

Postby swarmcatcher » 18 Feb 2019 19:41

ok - thanks for the reply

SingularitarianJohn
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Re: how to fast scan video files for a change in image

Postby SingularitarianJohn » 10 Aug 2021 02:48

Is there any way of scanning thru video files looking for changes in image.
The reason i ask is that i use a PTZ video in roof spaces to monitor for rodent and bird activity to assist in preventing the return of them.
This camera is linked to my computer and the video is recorded 24/7 - but there is no joy at all in watching nothing happening for most of the time.
ideally i would like to book mark them so i can scan to them quickly if its at all possible.

i have found the motion detection useful in that it highlights an eye of a rodent that i would otherwise miss but i still have to plough thru all the video.

Any advise would be gratefully recieved :D :D :D
Hey Swarmcatcher, I know I am a few years late but the solution for what you are looking for is very simple, follow these instructions to effectively get a different scan interval for scanning videos in VLC.

1)Open up VLC and go to the top toolbar with the "Tools" option.
2)Hover over the "Tools" option/tab and scroll down to "Preferences"and click it.
3)In the bottom left corner of the "Preferences"window click the All option field (it is a small circle next to the option field which says Simple)
4)Go to the left hand side of the expanded "Preferences" list and go to the "Interface" subsection/tab
5)Select it, then select "Hotkey Settings" as a suboption, and then look to the bottom right of the "Interface" window where it says "Jump Size"
6)For the respective settings, Very Short, Short, Medium and Long, select the scanning interval in terms of seconds for what would be appropriate for your scanning preference for each interval.

Each interval is equivalent to the sustained length of the button press of the arrow keys on your keyboard as well as any other keybinds you may have selected for your scanning directions on the timeline of the video.

I recommend lower values like 1 second for all intervals if you want to have sustained keypresses hasten in pace in terms of respective seconds which pass by for sustained keypress interval. For example, with the very short jump length interval, this is equivalent to a single key press, and each respective duration of sustained keypress augments/increments the scanning periodicity/speed by a factor of second (per minimum 1) as input in the hotkey settings submenu.

So, if you hold down the right arrow key to scan forward for example, it will scan second by second, but it will go 4x faster, but not 4 seconds per interval per se. It will be scanning at a ratio of 4 seconds (video time) to 1 second of real time.

I found this to be extremely useful in scanning long videos where I usually set up an interval of 1 second per respective option to scan more indepth and analyze videos to the best of my ability for crucial information. This is especially useful with security footage or like in your example, to find infestations of vermin and the source of their habitation, what they are effectively doing in your attic, etc.

For extremely long footage, I would recommend a scan interval of 1, 1, 2, 2, or (1, 1, 1, 2) which effectively cuts down a minute by a tenth of the time (6 seconds real time = 1 minute video time).

VLC as an application does not accept float values or decimal values as approximate intermediaries to precisely scan faster or slower, it only accepts whole unit positive integer values.

Hope that helps my friend, even though I am three years late!

Sincerely,
John Lasheras / Singularitarian


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