Searching through already-captured AVIs for motion.

[Sirim 0]

I have several weeks worth of CCTV footage to search through for a particular event. Is there an application which will search for motion in the AVIs and flag up potential times of interest? I have no problem with getting plenty of false positives, but looking through this amount of footage in its entirety even at 5x would mean wasting a ridiculous amount of time. I expect there are very few occasions where there is any motion in the AVIs, so looking through each occasion that motion is picked up would be absolutely fine.

 

I have spent a fair while searching for software that does this through google (and a brief while this forum), but have got nowhere. All solutions seem to require the motion detection to be performed as the video is captured, rather than analyzing already-captured files.

 

Any advice offered will be greatly appreciated.

[rory 0]

Just need something that can scan through the frames and look for changes ..

check out this program

http://www.imagemagick.org/script/index.php

http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=16055

 

also avidemux lets you save all the frames from a video as jpegs.

then just need something to compare them.

[Sirim 0]

Many thanks for the quick response, Rory. I've had a look at the links and it seems like a many-step process, but if it works it's well worth it. I'm afraid I'm not familiar with perl, but it would be helpful if the script could be modified to output the relevant time or frame numbers of the motion, rather than the JPEGs of it, as I wouldn't know how to get the time or frame number from the ouput.

 

I'll get cracking with the process and see how far I can get.

 

Any other suggestions are still most welcome.

[Sirim 0]

I'm not getting on too well so far with this method. I've spent several hours on it, but haven't managed to verify the imagemagick installation by using the reccomended method of 'convert logo: logo.miff', followed by 'imdisplay logo.miff'. The first command seems to work (it creates the file logo.miff), but 'imdisplay logo.miff' does not launch imdisplay at all, let alone opening the file 'logo.miff'. Typing 'imdisplay' without any paramaters or double clicking on the exe launches it just fine, though. Also, I haven't managed to get either strawberry perl or activeperl working from the command line (the 'perl' command is not recognised). This solution seems tailored more for those with a lot of experience with perl (and thus probably unix-shell systems) than I do.

 

Surely there is a much simpler solution out there than this.

[Securame 0]

Subscribing to this thread; if anyone knows of any program that can easily do that, I would also be interested on knowing. We work with many investigators that sometimes use covert cameras that have no motion detection, worst part is when you have to go through those videos to find any event...

[Sirim 0]

I'm now working with SafeMotion, found at http://www.safeware.ca/support.php .

 

Interestingly enough, I managed to find another thread here afterwards, by searching for 'site:www.cctvforum.com SafeMotion' with google: http://www.cctvforum.com/viewtopic.php?t=21597&p=131340 .

 

From what I can tell it's a unsupported, discontinued beta with a few oddities:

 

I had some slight problems at first because I didn't realise the current directory in cmd had be changed to the application's directory (*facepalms*). I was fiddling around with the 'path' environment variable, so that it included the application's directory, though this was, of course, pointless. To get it running, type 'cd C:\Safeware\SafeMotion\' then use the safemotion.exe command with whichever arguments you want.

 

Note that by default the program saves the segments of video in which motion has been detected as files in its installation folder, not in the folder where the file you are trying to convert is located. They will overwrite one another on each analyse operation. You can specify the output destination with -o. It saves files in the AVI format, but does not use a codec to compress them (leaving it in full frame form), resulting in very large files proportionate to the original.

 

The application runs okay on its accompanying test video (although it did produce 2 false positives – this is so the application's demos on masking have something to avoid), but I have some problems when I try to run it on my own videos. It gets repeatedly stuck at the same point of each video file. For example on one file, it reaches 59% every time it is attempted, another file 58% on every attempt and a third file an annoying 99% on every attempt. Three files of the same size all stop at 48%. It doesn't always seem to be related to file size; it ends each time at 99% on a 40.7mb file, but each time at 98% on an 11.7mb file. I have not found a way to fix this. It was over 3 hours into testing that I found a file of my own that the program is capable of reaching 100% on.

 

For a couple of hours, this led me to believe the program was actually only getting this far through the video file. However, I'm not at all sure of the accuracy of the percentage progress measure or what it means in real terms. For example, for one clip, it ended at 58%, but had found motion that was ~78% of the way into the video. Looking at the video display, it reaches the end of the video. I'm now assuming that the progress percentage is completely independent of the actual progress and should be ignored. However, the output AVI seems to be speeded up by the inverse of the end progress percentage, meaning that it's duration is the end progress percentage of the original film's duration, if there is motion throughout.

 

I shall have to continue testing to ensure that all of this is indeed the case (I don't want to accidentally erase important footage because I relied on this program to check for it). The program does not seem to be maintained (last updated 7/23/2010) and there is no support forum, so getting help may prove difficult.

[Securame 0]

I will check it out as soon as I have some time, thanks!! " title="Applause" />