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!