Windows Media Audio

Windows Media Audio (WMA) are Microsoft's compressed audio formats. It's a generic name for several codecs that can be used inside it:

Windows Media Audio

Also known as WMA Standard or WMA Std, it was created by Microsoft to compete against MP3, that was quickly becoming the de-facto standard format for lossy compression.

Even though Microsoft claims it is able to deliver the same quality as MP3 at half the bitrates, that statement is certainly false. A more realistic number would be same quality at around 25 % smaller bitrates - and that applies to low bitrates only. At 128kbps, it is easily bested by LAME.

WMA Standard is the second most widespread lossy format (only losing to the ubiquitous MP3), mostly thanks to Microsoft's aggressive marketing tactics.

Windows Media Audio Professional

Windows Media Audio Professional (WMA Pro) was recently released to address limitations in WMA Standard. It supports multichannel encoding and high resolutions (24bit, high sampling rates)

Since it's backwards incompatible with WMA Std, Microsoft took the opportunity to make a high quality encoder out of it. Meanwhile WMA Std lost even to MP3 in an informal public listening test, WMA Pro was ranked at the top (next to other high quality formats) in a similar test.

These days, Microsoft is pushing the Pro codec for inclusion in the next generation DVD standard as standard audio format.

Windows Media Audio Lossless

This is the mathematically lossless codec in the Windows Media family. Compression efficiency-wise, it doesn't come close to the default settings of FLAC, WavPack, Monkey's Audio and ALAC, see Lossless comparison for more details. Several releases of Windows 10 had faulty decoders built-in and lacking a specification few independent implementations exist and decoding is not always lossless.

Windows Media Audio Voice

This codec, among the first ones to be added to the Windows Media portfolio, is VoiceAge's ACELP.net. It delivers very acceptable voice quality at bitrates around 4 and 20 kbps.

Additional Reading

• Description of Windows Media Audio codecs at Microsoft
• Lossless Codec Comparison