Pros and Cons of Web Interfaces in Video Surveillance Applications

Wow – longest headline ever.

A very common request is a web-based interface to the video surveillance system. An often used argument is that the end user won’t have to install anything, and that the system is readily available from a variety of platforms, after all – works on macs, PCs, my 5 year old cell phone and my wife’s spanking new iPhone*

Most people are probably familiar with ActiveX controls that are needed when streaming various video formats from a camera to a web browser. While you may not think that you are “installing” anything (since the ActiveX or plugin does not necessarily appear in the Add/Remove programs window), you actually DID. A piece of executable code was downloaded and written to your hard drive, not unlike downloading and running a regular installer. ActiveX controls may require numerous supports DLL’s, which will be downloaded on demand. So even if the installation method is a little different for ActiveX, you are technically installing something on the machine.

The ActiveX controls are platform dependent (you can’t use a windows control on a mac), and they present a security risk unless managed carefully, but then there are Java Applets. These are sort of platform independent,  but can be (always are) a little slower than ActiveX. Adobe Flash is another option, but it won’t work on my wife’s iPhone, the same goes for Silverlight.

Although the second part of the argument is technically true, there are some costs to bear; although getting text and static images on the screen using baseline HTML is trivial, interactivity and streaming video is a different beast altogether. A commonly used technique is AJAX, which pretty much boils down to issuing requests asynchronously to a server using a XML object, but the XML object differs from browser to browser, so you need to write two different pieces of code to accomplish the same feat — on the same OS! Granted, the handing of the different browsers is well documented, and libraries exist that helps the developer overcome these annoyances, but for all intents and purposes, we have just doubled the number of platforms (IE and “everybody else”). The same applies to CSS, and even PNG handling.

Some companies will happily put together a “web solution”. But if you are still pretty much locked into Windows, IE, and you STILL need to install a bunch of ActiveX controls, what’s the point? Often the web solution is a little less useful than the traditional Windows application since the developers are limited to the browsers capabilities, whereas the old-skool application can pull all the levers in the system.

Recently Adobe added GPU accelerated video playback to Flash, and HTML5 is supposed to support H.264. Javascript is now very fast on a wide range of browsers (IE 9 was shown at MIX10 and looks promising, Chrome has always had fast JS). So perhaps a viable solution for desktop PC’s and macs will be available before too long.

*actually she has a Nokia phone, but I needed to add the iPhone in there somehow.


Author: prescienta

Prescientas ruler

4 thoughts on “Pros and Cons of Web Interfaces in Video Surveillance Applications”

  1. I don’t disagree with anything in this assessment. But I have to answer the question of “what’s the point?” The point is that ActiveX controls are dramatically more seamless to the end-user and whoever’s responsible for managing their desktop than are thick(er) clients. While far from perfect, it’s often “good enough” experience-wise to give the illusion of using nothing but a web browser. It’s a weak position–I know. But it’s the point.

    As you allude, the new opportunities in other technology like HTML5 and Javascript are exciting.

  2. Agreed with your assessment.

    One point I would add/emphasize is that web UIs for video surveillance almost universally provide less ‘functionality’ than thick client UIs so the user sacrifices performance as well. Some argue that these are just ‘bells and whistles’ but I think most users would notice material deficiencies in web UIs for video surveillance compared to thick clients.

  3. I agree with the motivation for using ActiveX controls, but if the end user interprets “web interface” as “works on my mac”, then the term might actually be a little misleading. A desktop installer should not cause any confusion. 🙂

    But perhaps there is another reason for wanting the Windows/IE solution – even if you are locked into one platform; a lot of times you don’t want to carry a 500 MB installer around, just to take a peek at the driveway while visiting the in-laws. Desktop applications routinely take up hundreds of megabytes, so a Win/IE solution with a much smaller footprint (and a more limited feature set) might be just what the doctor ordered.

  4. “a lot of times you don’t want to carry a 500 MB installer around, just to take a peek at the driveway while visiting the in-laws.”

    Agreed, and that’s been the most common use of web interfaces traditionally, as a secondary option for lite access

    btw – the 500MB installers for VMS clients is problematic, this is not universal (a number are under 100MB) but large installation size causes issues

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s