Those Special Codec Moments…

The following is not gibberish: A portmanteau is a blend of two or more morphemes. The word codec is a portmanteau of “compressor- decompressor” or, more commonly, “coder-decoder”.   Wikipedia explains: A codec encodes a data stream or signal for transmission, storage or encryption, or decodes it for playback or editing.

If you have been involved in dynamic sign content, you know those moments when the screen gives you a blank stare, and you fear that your beautiful video has fatal flaws? Well, isn’t it almost always the case that this is simply due to a missing “codec?” Then you go on the hunt to fix this embarrassing situation before the client sees the project. It’s pretty funny to hear audio and see nothing on the screen, and run to check the cables. Admit it, we all do that. A good hunch, but not relevant.

Codec for VideoLet’s talk about codecs, because making the move from digital print to dynamic signage requires that you know how to avoid those precious codec moments.  Although it has many other definitions, the term “codec” has become synonymous with digital video playback and encoding.

If you are in the business of graphics, digital print, advertising, or the sign industry, you are very familiar with lossy file formats, such as jpgs. The compression achieves a manageable file size, but there is data loss in the process. Images can look pretty pixelated after some edits and “saves.”  Well, the same holds true for codecs.Some popular codecs are “lossy” – losing some quality to achieve compression –  and some are “lossless — typically used for archiving data in a compressed form and keeping every byte of information present in the original stream.

What does this mean to you? Well, if you are rendering content for high-quality display (the good stuff all of your clients want), then like our media engineers at LobbyPOP, you want to use a lossless codec. All of those edits, text changes, music tweaks, video insertions, and saves, saves, saves, will create a pretty unpretty mess if you use a lossy codec in the process.

Of course, your final files will have to be decoded with the proper codec. We are familiar with one big name, popular content management system that doesn’t have the codec to decode MP4 files! The notion of AVI being a codec is incorrect as AVI is a container type, which many codecs might use (although not to ISO standard). There are also other well-known containers such as QuickTime, RealMedia, Matroska, DivX Media Format and containers defined as ISO standards, such as MPEG transport stream, MPEG program stream, MP4 and ISO base media file format.

Determining Codecs (thanks to Cisco for this information below)

Many tools are available to analyze a video file to determine what codec was used during encoding. One is AVIcodec, which you can download from http://avicodec.duby.info. The program recognizes most video file formats and delivers additional details in an easily viewable interface. Figure 3 shows a sample of the download output.

Figure 3. AVIcodecAnother program that is simpler is GSpot, which you can download from http://www.free-codecs.com/download/GSpot.htm. Figure 4 shows the output of the same file when viewed with GSpot.

Figure 4. GSpot 

Well, this blog was a bit more technical, but remember, we gave you risqué news in the last post!

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The Display Wars are Over… Sort Of

Remember back in early 2010 when we compared Plasma screens and LCD display technology? Well, that post covered a lot of ground, and the decision-tree is still a valid and great tool. But now we have a third horse in the race, and it looks like a triple-crown winner… if price is no object. LED-lit LCD screens are almost perfect.

The difference between plasma and LCD wavered for some time, with each offering different economic and visual benefits depending on the model, price, and time in the life cycle of HDTVs. But in the past couple of years, with the advent of increasingly sophisticated LED backlighting, we finally have a true winner. With its unmatched energy efficiency, LED-based LCD is the best flat-panel HDTV technology. Unfortunately, it’s also generally the most expensive. — CNET Technologies, June 2011

Okay all you traditional (digital print, routing, illuminated channel letter) sign professionals, here’s something you are familiar with: Cold Cathode and LED. Yup. It’s here, too, in dynamic digital signage. Traditional LCD HDTVs use cold cathode fluorescent lights (CCFLs) to illuminate the screen. CCFLs are similar to the fluorescent lights you might see in your lamps and overhead light fixtures. They use a charged gas to produce light. LED-LCD screens, like their name implies, use light emitting diodes (LEDs) to illuminate the display.

LED LCD BrightSo what are the advantages when it comes to digital signs? Well, as you might have guessed, LED-LCD is thinner, brighter, and the contrast ratios are out of this world.

For this advantage, LED HDTVs command a premium; for all major HDTV manufacturers, LED-backlit HDTVs can cost a few hundred dollars more than CCFL-backlit HDTVs of the same size. Generally, plasma HDTVs tend to be the least expensive, priced at equal to or slightly less than CCFL-backlit HDTVs. However, that savings means the screen will be thicker and much more power-hungry, even if it does offer as good a picture as an LED-backlit HDTV.

How good the picture looks, especially if you’re a videophile or a cinema fanatic, is the most vital aspect of any HDTV. Specifically, peak white and black levels determine how detailed a picture can look on a screen. Historically, plasma HDTVs have produced the best black levels, but the domination of plasma in this field, however, is over. The current PC Magazine Editors’ Choice HDTV, the LED-based LG Infinia 47LW5600, puts out only 0.01 cd/m2, the best level we can measure.  Of course it’s an LG – one of LobbyPOP’s favorite brands!

So, you if you recall that decision tree of our LCD-Plasma comparison post, then consider this your update. If energy consumption is important, you will be looking at LCD, of one kind or another. If price is most important, you will be looking at plasma for the larger sizes. If quality, however, is your mantra, and price is no object, then the new LED-LCD screens will be your pick. But always, always, always choose a commercial screen and NOT a consumer model for your sign systems.

It bears more than a mention here: Commercial screens have what it takes to get the job done, vs consumer screens that pale in comparison.

The main differences are:

  • Commercial units have MORE modes of Video/Picture selection.
  • Commercial units have “Adaptive Picture Mode” and consumer units does not.
  • Commercial units allow for PC inputs, which few consumer models offer.
  • Commercial units have more Decorder formats.
  • Commercial unit has actual HDMI in with HDCP. Most consumer units have HDMI  In, as DVI with Adapter.   This is a pretty big difference.
  • Often, commercial units have separate antenna in and separate cable in (more versatility).  The consumer units usually have a single antenna/cable input.
  • Commercial units come with a two- or three-year warranty on-site. If you use a consumer model for a commercial sign application, you void the warranty.
  • Commercial models have heat management systems to accommodate continuous operation. Consumer models are not built for 24-hour operation.

Well, you get the picture! (Pun intended 😉 )