Lossless compression
In contrast, lossless compression squeezes data into smaller packets of information without permanently discarding any of the data. Instead of permanently discarding information, lossless compression discards it temporarily but provides a "map" with which the codec can reconstruct the original file. Lossless compression results in superior audio quality, but lower compression rates.
In the lossy example, our codec had some general rules for reconstructing the message--basically to add vowels and spaces in order to form English words. It wasn't perfect because it didn't know which English words to choose, and it wasn't always sure where one word ended and the next began.
Lossless codecs, on the other hand, are perfect. To reconstruct our message perfectly, however, would mean having a much more sophisticated set of rules. A lossless text codec would have to reproduce not only words but sensible phrases. It would have to be able to break words correctly. And it would have to have a mastery of the English language's inconsistent spelling patterns. It would in fact be, as the computer scientists say, a nontrivial endeavor.
The same goes for lossless audio codecs. They are difficult to develop (and thus expensive to license), they require substantial computing power on the user's machine, and the file savings are not as great as with lossy compression. Sadly enough, it appears that for the current time, lossy compression is necessary for knocking large audio files down to Internet-appropriate size. The good news is that lossy compression schemes are becoming more advanced, and over time the differences will become less and less noticeable to the human ear.
Now that we have discussed lossy and lossless compression and the types of protocols that enable the efficient delivery of compact audio files across the Internet, let's review the audio formats available on the market. Most of these formats will be discussed in greater detail in the rest of the book.
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