After a long, exhausting day you came home, had your dinner and then sat in front of the TV looking for a nice relaxing movie. Nothing! Then suddenly you remembered that you bought the CD of the new, Oscar-winning movie "Million Dollar Baby". You took out your laptop, inserted the first CD and hit "play". To your surprise, the only thing you could see was a green screen. You took out the CD, cursing at the media market that gave you a "broken" CD for the fifth time. Tried the second CD; again the frustrating green screen. First thing in the morning, you took your "broken" movies and went to the shop. Having yelled at the owner of the shop for five minutes, you suddenly noticed the cynical smile on the guy's face. Having the opportunity to talk, the shop keeper said "CODEX".

All you needed were the codecs for these movies. They were not broken; they were just coded in a "foreign" language to your media player. The codecs were the dictionary that your laptop had to use to translate the absurd computer language to the nice scenes of the movies.

Every video, audio, picture or even word document files are coded in a different way. In the case of big data entries like movies, the computer has to use different algorithms to compress the data so that the size does not exceed the standard limits. We see this compression in PDF files (Acrobat Reader), in MP3 files (WinAMP), in MPEG files (movies), in each and every data storage file that you can imagine. While the compression is being done, the programs use some kind of a dictionary. Without these "dictionaries" (codecs in the case of video and audio files) the code would seem as meaningless to the player or the viewer as it is to you. So you have to install certain codecs to be able to use certain files.

Some codecs replace the repetitive symbols over the file, ome codecs changes the aspect ratio of the movie; some of them decrease the quality of the picture and yet, all of them turn gigabytes of data into fair size that can fit into a CD or a DVD.

As the user demands increases, codecs are multiplying in a logarithmic scale. There are several codecs that are musts for movie fans, however. You should install most of these if you don't want to be disappointed.

1. MPEG4 - It is the default codec which is already included in WMP.
2. DIVX - A series of sound and display codex which come with shareware DIVX player.
3. XVID - Relatively new, one of the most used video codecs.
4. AC3 - Most common sound codec.
5. Intel Indeo - Rather useful series of codec which a new version pops out everyday.

Overall the way movies are encoded is changing day by day. Everyday we see a new aspect ratio. Everyday we encounter a new codec. To many, it would seem that it is getting harder and hard to watch movies. The least you can do is to download a codec viewer program which would help you on your quest for a pleasant evening.