Digital Retailing Content Encoding

Author: Bill Gerba on 2005-01-03 23:23:10

First off, Happy New Year! Here's to hoping that 2005 will bring us all health, happiness and success, though in the digital retailing industry these wishes are already well on their way to becoming reality. It looks as if 2005 is going to be a banner year for all those involved in digital retailing, digital merchandising, interactive kiosks, dynamic digital signage, narrowcasting, captive audience networks, electronic billboards and signs, and all of the related product and service industries. I'm especially excited by some of the new products and features that WireSpring will be rolling out with new versions of our FireCast software for kiosks and digital signs in the coming months.

Today, though, I thought I'd try to shed a bit of light on something crucial to both the tech and business sides of digital retailing, namely content encoding. Whether running big-screen digital signs or attract content on kiosk touchscreens, your digital media needs to look great to attract attention and please your customers. And while many digital media network owners still consider the realm of video codecs, compression rates, quantizers and artifacting to be something of a black art, there are a plethora of new tools and guides on the Internet that try to demystify the process and help you produce great looking output right from a standard PC. And while the subject of encoding video could fill several volumes, I thought I'd provide just a bit of background information here, and then point out some useful links.

First and foremost, adhere to the principle of GIGO - that is - garbage in, garbage out. If you start with poor quality source content, you will end up with poor quality output. You could be using ultra-high bit rate DV (digital video) coming from state of the art equipment, but if it doesn't look crisp and clear, all the tech in the world isn't going to help you.

Second, some kinds of content compress, transmit, and display better than others. While you should be adhering to a few basic principles to make sure your content has the maximum impact, there are a few other things to keep in mind as well: If your screens have text, always make it as big as possible. Text on a moving background is not only hard to read, it also doesn't compress well. Large blocks of color do compress well, while gradients and fades do not. Don't rely on subtle detail to carry your message, be bold and direct. Finally, use contrast to your advantage. It can make text more readable and animated content more eye-catching.

Third, for all practical purposes (and still keeping in mind point #1 above), the format of your source video content will probably make a difference. Unless you're dealing with raw video (and unless you have terabyte upon terabyte of disk space and an amazingly fast computer, you probably aren't), all digital video files will have some kind of compression applied to keep file size down. On the high end of the scale is DV, which can take between 3 and 4 megabytes per second (25-36 Mbps) and offers the highest output quality. Consequently, it's the best stuff to start from when encoding your own content for kiosks or digital signs. Next on the list is MPEG-2, the video format used for HD-TV and DVDs. MPEG-2 files are frequently between 20-30 megabytes per minute and also offer excellent output quality. Finally, there's MPEG-4, the newcomer on the block, which offers output quality that can approach MPEG-2, with file sizes only 1/3 to 1/2 as big.

As I said, DV makes great source material, but is far too big to effectively transmit to dozens, hundreds or thousands of computers over the Net. MPEG-2 is also a good choice for source material (especially in higher quality, higher bit rate variants), and can also be small enough to send over to your devices (with a fast connection). Many graphics shops and service bureaus are comfortable with these formats; they�ve used them for years, and they are familiar with the idiosyncrasies of each... then there�s MPEG-4.

MPEG-4 was supposed to be the holy grail of video codecs, one that would produce consistently high quality video at a fraction of the file size of MPEG-2. While MPEG-4 files can look amazing, and they certainly tend to be smaller than their MPEG-2 counterparts, there are some caveats. First, they can be harder to encode than MPEG-2 files, and can take some trial-and-error to get set up correctly. Second, they take a lot of CPU horsepower to encode, and the general lack of encoding hardware means that the aforementioned trials and errors might take over your PC for a long time. And finally, there are a lot of different MPEG-4 codecs to choose from, each having a different pros and cons. This last part has been the subject of many a web review, but the best and most comprehensive review that I�ve come across is found over at Doom9.net, a resource for all things video codec-related.

These days, I recommend that everybody try out MPEG-4 to see if it fits their application. Most of the time it produces excellent-looking video that can be quickly transmitted over the Internet, making for more responsive kiosk and digital signage networks.

If you�re working on a digital retailing project that uses lots of full-motion-video content, I strongly recommend that you check out some of the MPEG-4 variants featured in the Doom9 link above. Once you�re ready to get started, feel free to contact WireSpring, and we�ll help you make the most out of your digital media.