#11: Processing and storing IP camera footage

    22nd Sep 13

    Commonly available IP cameras are great if you just want something that lets you quickly view a live stream from your laptop or smartphone, but if you want to keep footage more permanently (such as for a security recording) you can do that too without too much trouble. In this episode I show you how to use an Ubuntu Linux machine on your network to run as an FTP server to accept snapshots from your cameras, process those snapshots to add timestamp watermarks on the images, and then periodically convert them into a time-lapse video to quickly see what happened over a period of time.


    Parts Required

    • IP camera with FTP upload capability (eg: Foscam FS8918W)
    • Computer running Linux (I use Ubuntu in this demonstration)
    • ProFTPd (FTP server software)
    • Imagemagick (image processing software)
    • Mencoder (movie encoder software)

    Setting Up An FTP Server

    If you already have access to an FTP server you can skip this step, and go straight on to "Configuring Your IP Camera". You can even use a third-party FTP server located off-site if you like, but my preference is to run a local server. This has a few advantages, including limiting use of the very insecure FTP to your local network, and giving you the opportunity to do some processing of the images on the server.

    On Ubuntu, installing ProFTPd is as simple as opening a terminal and typing:

    sudo apt-get install proftpd-basic

    Ubuntu will install the FTP server and even start it for you automatically.

    However, there's one extra step you can take to increase security just a little. By default, ProFTPd does not jail users within a specific directory: that means anyone logging into your FTP server can see the whole filesystem. Let's lock that down a bit.

    Using a text editor, open the following file:


    Around line 34 you'll find the following entry:

    #DefaultRoot    ~

    Remove the leading crosshatch to enable that option, so the line shows:

    DefaultRoot    ~

    Save the file, then restart ProFTPd so it will see the changes:

    sudo /etc/init.d/proftpd restart

    Now users who connect by FTP will be jailed inside their home directories.

    I prefer to create separate users for each camera so they all end up compartmentalised, but that's totally up to you. If you want to create a new user for a camera, you can enter the following:

    sudo adduser camera41

    Of course you can substitute your own username convention to suit your requirements. In the example shown in the video I set up a user for camera 41, so I just made that the username for convenience.

    Configuring Your IP Camera

    Configuration options may vary depending on your particular model of camera and firmware version, but look for a section titled "FTP Service Settings" or similar.

    You'll need to enter the address of your FTP server: usually the IP address of the Linux machine if you're running your own server, otherwise it may be the hostname if it's set up in DNS.

    You'll also need to enter the FTP username and password you just configured a moment ago, and optionally specify a target directory name if you want uploaded images to be put into a specific location. Some cameras create the target directory automatically if they find it there, otherwise you may need to create it yourself on the server.

    In the case of Foscam cameras, you can't test the setup or configure an upload rate until you save the settings. Click the submit button, tick the "Upload image now" checkbox, and enter a sensible value for the upload interval. In my example I set the upload interval to 1 second.

    Watermarking Images With Timestamp

    Most cameras upload snapshot images with the filename set to something useful such as the timestamp. In the case of Foscam cameras, the filename is the camera identifier, then the timestamp, then a sequence number. That's useful information so I like to place the filename as a watermark in the image itself.

    You can process a collection of images using ImageMagick. If you don't have it installed on your Ubuntu Linux box already, open a terminal and enter:

    sudo apt-get install imagemagick

    ​This will give you the "convert" program which can be used to place text on images.

    In a terminal, go to the directory containing uploaded images and enter:

    for name in *.jpg; do convert "$name" -font courier -pointsize 20 -draw "gravity south fill black text 0,12 '$name' fill white text 1,11 '$name'" "$name"; echo $name; done

    That command can all be entered as one line, although it's wrapped here in the browser.

    This is a "for" loop that will step through all the files with names matching "*.jpg", and write the filename into them near the bottom center first in black and then in white. This helps the text stand out whether the background is light or dark.

    If you open the images after running that command you should see text added to the bottom that shows the filename. Here's one from the example shown in the video:

    Converting Images To A Time-Lapse Movie

    Now that you have a collection of watermarked images taken at whatever interval you configured in your camera, you can process them periodically into a time-lapse movie so you can quickly scan through what happened while the camera was recording.

    There are a variety of tools for doing this, but one that's easy to use is mencoder. If you don't have it installed, open a terminal on your Ubuntu Linux machine and type:

    sudo apt-get install mencoder

    ​Now you can go into the directory containing the watermarked images are run the following command:

    mencoder mf://*.jpg -mf w=640:h=480:fps=25:type=jpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o output.avi

    Once again that's all one line.

    This tells mencoder to operate on multi-file (mf) input, that it's processing images of type JPG at 640x480, setting the output video codec (ovc) to libavcodec, setting mpeg4 compression, and writing the output file to "output.avi".

    Here's the example video I created for the demo:

    Wrapping It All Up

    Of course you probably don't want to run those commands manually all the time, so you could combine them into a shell script and execute it periodically using cron. You'll probably also want to include a sequence number or (better still) timestamp in the name of the output file, so that you can come back later and easily see what period is covered by each movie.

    Got suggestions or feedback? Discuss this episode in the forum: forum.freetronics.com/superhouse

    #10: Workshop Tour

    5th Sep 13

    This episode is a bit different: instead of featuring a specific project, I pull back the curtain and give you a candid view of my home office / workshop so you can see where I work.

    #9: Power-over-Ethernet for IP cameras

    22nd Jul 13

    IP cameras are really handy, except for one thing: getting power to them. Learn how to hack an IP camera to add an internal voltage regulator and run power to it over the network cable.

    #8: Implantable RFID

    9th May 13

    In 2007 there was a lot of argument about putting RFID tags into Australian passports, and many people were saying we were destined for a future where everyone was implanted with RFID so they could be tracked by the government and large corporations. I wanted to understand the technology and the risks involved, so I did the only logical thing: I implanted an RFID chip in myself!

    I've shown use of my implanted RFID chip in previous SuperHouseTV episodes, but this is the first time I've shown the footage of me actually implanting the chip in myself.

    #7: Control door locks with RFID and Arduino

    3rd Apr 13

    Now that I've modified the Lockwood Nexion door lock on my workshop for Arduino control, the next step is to add an RFID reader near the door so that I can scan the RFID chip implanted in my arm to unlock the door.

    Note that I deliberately did not go into any detail of the RFID implantation in this episode, so it's safe to watch even if you don't want to see me doing home surgery on myself! I'll cover that in a separate episode so anyone who doesn't want to see it can avoid it.

    #6: Electronic door locks

    27th Feb 13

    Door locks are one of the most useful things to control from your home automation system. Using electronic locks you can give your house central locking just like your car, control them from your phone or via the Internet, or even control them using an RFID tag or implant.

    I modified a Lockwood Nexion keyless lock to allow it to be controlled by an Arduino, and linked it to my home automation system.

    View on YouTube: www.youtube.com/watch?v=mqEcJO0UafA

    Discuss this episode in the forum: forum.freetronics.com/viewforum.php?f=30

    "EtherMega" (Arduino Mega with onboard Ethernet) mentioned in the video: www.freetronics.com/ethermega

    #5: Installing conduit under an existing footpath

    9th Dec 12

    Electrical conduit allows you to run cables outside, underground, and in other nasty places. Sometimes though you have to get cable into places that look impossible, such as under an existing concrete path or driveway that you can't rip up. It's not as hard as you may think. I used a technique called "water boring" to install a conduit under a concrete footpath in just a few minutes, without having to dig up the path.

    View on YouTube: www.youtube.com/watch?v=9rXFU59D1uE

    Discuss this episode in the forum: forum.freetronics.com/viewforum.php?f=30

    #4: Making Home Automation Gear Quieter

    16th Sep 12

    I've found that the second-hand Ethernet switches I use in my home automation system have annoyingly loud fans, so I modified them to run the fans more slowly and connect to my Arduino-based environmental monitoring system.

    Links for this episode:

    Discuss this episode in the forum: forum.freetronics.com/viewforum.php?f=30

    #3: Power-over-Ethernet for Arduino Home Automation

    7th May 12

    I'm using Ethernet extensively in my Arduino home automation system for communication with devices distributed around the house, so being able to also provide power to those devices over the same network cable is a big time saver. Until now I've been using a "DIY" approach to Power-over-Ethernet (PoE) with midspan injectors sending about 10-12V down the wire, but I'm now converting it all over to use Netgear switches with 802.3af (48V) PoE support built in.

    This episode covers some of the options for PoE with Arduino, and demonstrates how you can do it both in a cheap DIY method and using commercial PoE switches.

    Links for this episode:

    Discuss this episode in the forum: forum.freetronics.com/viewforum.php?f=30

    #2: Arduino-Controlled Home Automation Switchboard

    23rd Apr 12

    The automation switchboards in my house have Ethernet interfaces thanks to an EtherTen (just like an Arduino Uno, but with built-in Ethernet and PoE) mounted inside. This episode shows the switchboard internals, including how the EtherTens switch output loads around the house. It also shows the termination of the house network that starts out as a bit of a mess, but is much neater by the end of the video.

    Links for this ep:

    Discuss this episode in the Freetronics forum: http://forum.freetronics.com/viewforum.php?f=30

    #1: Home Automation System Architecture

    12th Apr 12

    A basic introduction to the approach I'm taking with linking high-voltage devices in my house to the automation system, and how logical inputs are associated with outputs using MQTT.

    Apology: The "threat" I attribute to Andy in the video is not something he's ever said, or something I'd expect him to say. He's a peaceful soul, and it was purely hyperbole on my part when I was recording the video!

    Links for this ep:

    Discuss this episode in the Freetronics forum: http://forum.freetronics.com/viewforum.php?f=30

    Music credits: the track used in the intro and ending is "Interface" by ElectroLatrine, www.electrolatrine.net. Used with permission.

©2013 Jonathan Oxer Privacy Policy | Terms of Use | Site Map