Samsung and .sec files

Yet another file extension from Samsung! The exports look something like the folder structure here. Samsung have made things a little easier by including an index file but the .xml format can be a little temperamental. In older versions of Internet Explorer and inside Windows XP it has always worked with no problem. In other browsers and in Windows 7, you may not get what Samsung had anticipated. July 22 Update: A colleague from The Netherlands has helped out here with the following guidance on opening these in Win 7: “When opening the XML-index in Internet Explorer 10 using Windows 7, you can fix the view by enabling the following setting in IE10: Tools > Compatibility View settings > Display all websites in Compatibility View” This is what it should look like. It’s a handy index of what is on the evidential disk and what user created it. The hyperlink to the file is then shown. These .exe files are in a date formatted folder. Alongside each .exe is a .sec file with the same name. In the Samsung index.xml file, the file size of each .exe is shown. In comparison, when viewing the .exe files within windows they are tiny! The files of matching size are the .secs. When running the .exe, the player loads into RAM. At the same time the player identifies a corresponding .sec file and also loads this. If you have files of some length then this can take quite some time. It is a very basic player and as such can be a little tricky to use on large files. In my experience, I have found that scrubbing or trying to review large files have caused it some problems. As such, I had to question whether it was easier to review the large streams out of the Backup Viewer? Yes! Firstly, from the file sizes and naming convention, it is pretty obvious that the .sec is the video stream. By dropping this into MediaInfo reveals all. So, we have a standard h264/AVC stream. Before we get to ‘containing’ this, its worth having a loo at the raw data. This is quite common now and can help with identifying where a file has originated. In the header of the file before the start of the video is the model number of the DVR used. The SRD-1670D. The date and time information is held all at the end of the file, but without some serious reverse engineering, its pretty hard to get out. Whilst on the subject of time-codes, many companies now offer the ability to extract their video but hardly any offer the ability to extract the time information. Wouldn’t be hard for them to create a subtitle file…. just a thought! Anyway, back to the .sec file. As it’s a standard stream (thank-you Samsung for actually sticking with a standardised format), it can be contained within a file of your choice. Using FFmpeg to output into avi:

ffmpeg -i 0010600.sec -vcodec copy -vsync drop -fflags genpts -f avi 0010600.avi

Remember that if the frame makeup is critical then ffprobe can give you the entire frame structure and exact frame extraction can be carried out for image analysis.

The file will now scrub much better in other players. To give an estimation of time, its very easy to place a timecode over the top and adjust the frame rate in order to have some time referencing.

DISCLAIMER: the original timecode from the original export should be used for time accuracy if this is critical.

We have 89820 frames over a duration of 7 hrs 59 mins – The time was on the original index and the viewer. That’s 479 minutes.. or 28740 seconds 89820 / 28740 Equals 3.12526 FPS By using this frame rate in Virtualdub and adding on the TimeCode Generator, the review time was accurate within milliseconds.

I have found that for a number of small files, the time  / frame rate was much more accurate. The file used here was for an 8 hr duration so there was always going to be a bit of play in the variable recording speed.

For the smaller files, perhaps including a number of cameras, it may not be necessary to deal with the time. In those cases, a simple rewrap and then review of cameras in forevid offers a quick solution.

Dec 2013 Update: A newer version of the player seems to deal with large streams much better with immediate loading and a much faster scrub / search.

June 2015 Update: IMPORTANT!

If your new version of FFmpeg fails when you attempt a stream copy or transcode to Uncompressed – please obtain an older version from Zeranoes site – Link to 32bit versions.

http://ffmpeg.zeranoe.com/builds/win32/static/

The new version is a bit fussier on non standard formatting and, as such, can fail in the process.

Remember, it is still the users responsibility to validate the results and compare the output against the original.

As always, I hope it helps.