Note: Before you continue, make sure you have what is takes to use a computer and know its
in-depth capability good enough.


:::: INTRODUCTION
Every time you play a video file with windows media player, the player it self scans the file and see its format, format is also known as ALGORITHM, which is the basis of ALL compressed files (MP3, images, video, ZIP etc...). ALGORITHM is an arithmetic procedure, which simply is executed to compress a file (for example ZIP files). The same way is used for multimedia files (video, audio).

Each compressed file must have its extractor, or in other words its unique decoder (application) to resolve the used ALGORITHM in the specified file (like for example to open ZIP files you need WinZip installed in your computer). For video and audio files, the type of extractor/decoder is called "codec", where "co" is "compressor" and "dec" decompressor. "Codecs" can only be executed by media players like windows media player. They're like *add-ons* for multimedia players, and once a video file is loaded, the compatible codec is executed to start ALGORITHM procedure and play finally the file.

:::: THE STORY

:::: DIVX FORMAT
DivX format delivers high video quality rates at a very low cost in size (megabytes). It is well known as the best compressor around the world and it is already being used by 2-3 million users all over the world. While a DVD disc can keep a movie in extreme quality in 4 Gigabytes, DivX can keep it in a standard CD-ROM disc (650 megabytes) with quality ratio 7/10 (which means its only 3 points worse in quality while DVD haves 10).

Its conversion can reach unimaginable time rates in a standard pc PIII 500 with 128MB ram. Lets say you have a movie in 16:9 screen size (wide screen) and its length reaches 2 hours, for 1 CD, DivX would take about 4-5 hours to encode the movie and for 2 CD about 3-4 hours. Yeah it would take less time to encode it in 2 CDs than 1, that's because the codec encodes the whole file without using high compression level which gives you high quality results.


:::: DIVX AUDIO
DivX simply uses standard MP3 format. MP3 and DivX format (video/audio) is the most well-know combination for creating high-resolution copies (both video and audio). Of course you can use whatever format you wish. Some of them are MP2, WAV, RMA, OGG. Audio in DivX (also in all formats) is a different stream than video. A movie generally holds 2 streams, one video and one audio. Each of them are completely independent. Its like loading a media player for audio and a different player for video. When you change a scene in a movie in time 00:43, then audio skips to 00:43 too.

Lots of people have report problems with audio-video synchronization (like delayed audio while searching/tracking the movie). This problems lies most in the codecs. Lets say you use some codec to encode audio, and after that install a new but different codec than the old, then the new is used for playback. That is THE problem; the DECODER is different than the ENCODER, and the capability is certainly wrong. Of course this is not the main problem while LOTS of other explanations can be found/disorient.


:::: DIVX CONVERSIONS
While converting a movie, you can use various of encode types to control bitrate. For example, you can encode a file and tell the encoder to raise bitrate (quality) only when its needed (for example when a scene haves allot of colors, items etc.).

The following are the well known encode types:

:: CBR (Constant Bitrate)
Uses a standard bitrate for all movie frames. Perfect for archive purposes.

:: VBR (Variable Bitrate)
Encoder scans every frame and uses the needed bitrate (from 0) Good for 1CD encoding.

:: ABR (Average Bitrate)
Same as VBR, but result file size can be estimated more easily while the encoder uses the given min/max bitrate (for example min-500 to max-800).

:: SBC (Smart Bitrate Control)
This is a special EXTERNAL encode type used with NANDUB (www.nandub.org). This can only be done with DivX 3.11 which is actually 2 codecs, the one is LOW MOTION and the other HIGH MOTION. NanDub can switch these codecs and use them properly to accomplish a perfect result in quality. However SBC is not as simple as it sounds, since it depends on how you configure its settings (nandub), and believe me that's certainly NOT an easy thing to do!


:::: FINAL WORDS
DivX is the most fast, simple, qualified and first of all, its a free encoder. Free ONLY for personal usage. To use the codec for commercial purposes you need a license from DivXNetworks, visit www.divx.com for licensing information.

:::: Thanks to Deathstar for spell checking: [email protected]