WMA file format

A format of audio stream coding deployed by Microsoft in 1999, it has been serving as a foundation for Windows Media. Its purpose is to store and distribute audio content. Firstly, it was considered a real alternative for MP3, but then, when ACC appeared, WMA partially lost its significance. It differs fundamentally from MP3 by one realization and can be installed on an equal basis with other system codecs of Windows 9x.

A good compression quality characterizes WMA, and therefore it has been adapted later for many audio players, mobile devices, and Playstations. However, due to excessive closure, files in this format cannot be played back on other platforms with satisfactory quality. The new version allows for multi-channel coding of large audio files and coding of voice data. In addition to that, the delay in coding has been significantly diminished thanks to the technology of reduced time dilation.

The name of WMA is being used simultaneously for the file format and the codec. There are some types of the format:

• WMA, a close analog for MP3;
• WMA Pro, high-quality sound files with a wide range of channels;
• WMA Lossless, for lossless compression;
• WMA Voice, for compression of voice content into low bitrate files.

According to Microsoft programmers, an audio file of 64 Kbit/s bitrate has a similar sound clarity as the tracks from the original CD. However, some of advanced users do not share such views. Most often, WMA files are generated in Advanced Systems Format which contains both audio and video content. One of the failures is the impossibility to support bitrate of more than 160Kbit/s.