There are many encoders available for storing digital data. While there are general-purpose encoders that implement different compression algorithms, the best encoder is one specifically designed to compress certain types of data. This is because some algorithms are better suited for particular uses, and the encoder used can be optimized so it works faster, more efficiently and provides targeted features as opposed to just compressing anonymous data. Encoders that specialize in general archiving of arbitrary files are regularly used, although some of these files already employ complex encoding schemes, so the extra compression can actually increase the file size instead of reducing it.
An encoder is a piece of computer software that combines two other pieces of software, or computer libraries, to form a complete program. The first is the compression algorithm, which is the actual formula used to take digital data and convert it into a file smaller than the original. The algorithm is wrapped in a program that can be integrated into an operating system called a compress-decompressor, or codec, which is the implementation of the compression scheme. A software encoder provides a usable interface that can call on the codec to convert data into the format specified by the algorithm so it can be unpacked at a later time or stored in a small amount of space.
Some of the most frequently used encoders deal primarily with images. Depending on the depth of features required, the best image encoder for some people will have a simple interface and support multiple file formats so images can be converted to whatever type is needed for another program. Some image encoders also include alternate implementations of standard algorithms, providing better quality for a slightly larger file size, or maximum compression with some loss of image resolution.
For general archiving, there are several types of encoding software with varying features. In a case where a large amount of files needs to be compressed, there are encoders optimized with only a single powerful algorithm that can get incredibly high compression rates — at the cost of speed and a lack of portability to some other encoding software. Alternately, there are encoding programs that will compress multiple files and create an easily used self-extracting file that results in a larger file size but adds portability and an easy way to reproduce a file tree or directory structure without effort.
There are several other specialized encoders, including those for quickly compressing streaming video, audio tracks or three-dimensional (3D) data. Each of these requires a special codec and, in some cases, external support hardware. These types of encoders can include free versions and their professional counterparts that have become industry standards, so choosing the best one will be a matter of evaluating the cost of the software versus the features provided with it.