Windows Media Audio

Icon of WMA files in Windows Vista OS

History

The first WMA codec was created on the basis of Henrik Malvar's developments and his command. Malvar was the senior researcher and the head of the Signal Processing group in division of Microsoft Research. Its command worked on the project under the name MSAudio. The first provided codec was called MSAudio 4.0. Later it was provided as Windows Media Audio, as a part of a packet of Windows Media Technologies 4.0.

Unlike the predecessors, Microsoft sensibly judged what to compete with a MP3 in the field of a qualitative sound and high bitrates is not present sense. And here on average and the lowest class it was worth and competing. If on CD MP3 format was ideal for house collections, for transfer on the Internet in the mode of "network broadcasting" MP3 files were too bulky. Only owners of fast communication channels could listen to musical compositions with the standard bitrate of 128 kbps in the mode of "real time", and at a speed of 33-56 kbps, standard for modem connection, the quality of music became already unrecoverablly terrible.

For this reason Microsoft also put emphasis first of all on low bitrates – and did not lose: the latests version of the WMA codec provide quality of a MP3 - 128 already at the bitrate of 48 kbps (and the upper level of WMA bitrate originally reached 160 kbps), at the same time during coding in WMA variable bitrate is initially used.

However the appetite, as we know, comes to meal time, – and starting with the ninth version of the codec which appeared in 2003, Microsoft began to propagandize WMA as real replacement of a MP3 even in the field of "audiophile" records. In particular, developers stated that WMA with the bitrate of 192 kbps already completely corresponds to original CD quality (while the MP3 demands, at least, by one and a half times of a bigger data stream).

Criticism

Nominally the WMA format is characterized by good capability of compression that allows it "bypass" a format MP3 and compete by parameters with formats Ogg Vorbis and AAC. But as it was shown by independent tests and also at subjective appraisal the quality of formats after all is not unambiguously ekvivaletny, and advantage even before MP3 unambiguous as it approves by the company Microsoft. Especially It should be noted that early versions of a format (or its implementations) had problems on low flow rates. Also many music lovers and owners digital players dislike the WMA format for low resistance to errors. If by coding/transfer of the WMA file some part it is damaged, then reproduction of the file becomes impossible, both after the place of damage, and for several tens of seconds to it. (For comparison: at damage of the file of a format MP3, it can still be reproduced from the beginning to the place of damage, then to pass several seconds and to reproduce further up to the end; sometimes errors in several byte in the file MP3 are aurally hardly noticeable or are not noticeable in general.) However the WMA format constantly develops so it is possible to assume, the quality will be optimized.

The majority of portable audioplayers supports the WMA format along with a MP3. This format is very badly supported on alternative platforms (owing to its closeness).

Microsoft included in WMA support of a numerical control system copyright (DRM) (the system of protection). It the impossibility to listen to the protected compositions on other computers is the main consequence, besides, on which the composition was loaded from musical shop.

Advantages

The program coder is distributed by Microsoft for free, together with the standard Windows Media Player player, the majority of programs of independent producers can reproduce WMA files. At this Microsoft took care of supplying users with convenient means for recoding in WMA of already available MP3 collections.

The MP3 is suitable for creation of small demonstration rollers, say, for placement on web pages, WMA much better – especially if it is about voice record.

Coding without loss of quality, multichannel coding of a surround sound and coding of a voice is provided in the latests version of a format, starting with Windows Media Audio 9.1.

Links

HHlife: WMA