Windows Media Audio

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Windows Media Audio (WMA) are Microsoft's compressed audio formats; "WMA" is a generic name for several codecs. .wma files (and .wmv files) are ASF container files with a suffix indicating content, much like would later be done by renaming audio-only mp4 files into ".m4a".

Use of these codecs largely depend on Windows components, and support has waned over the years to the point where they might be considered abandonware: by 2011, Microsoft's own music store abandoned WMA lossy completely in favour of MP3[1], and certain Windows versions have been shipped with broken WMA Lossless decoding.[2][3]


Windows Media Audio[edit]

Also known as WMA Standard or WMA Std, it was created by Microsoft to compete against MP3, that was quickly becoming a de-facto standard format for lossy compression. Once the second-most widespread lossy format, there is as of 2021 only one major music store that even offers WMA lossy downloads[4]. There are still around hardware WMA players - including in-car units.

Upon release, WMA was aggressively pushed by Microsoft with promises of MP3 quality at half the bitrate, a claim debunked by independent listening tests[5].

Windows Media Audio Professional[edit]

Windows Media Audio Professional (WMA Pro) was recently released in the early 2000s to address limitations in WMA Standard. It supports multichannel encoding and high resolutions (24bit, high sampling rates). Improving over WMA standard, WMA Pro scored as statistically tied with top encoders in independent listening tests at the time (without lending credibility to Microsoft's claim of MP3 quality at half bitrate), but like WMA Standard it is largely abandoned.

Windows Media Audio Lossless[edit]

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[edit]

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[edit]

  1. https://support.microsoft.com/en-us/topic/support-for-rights-managed-purchases-in-zune-69161d07-acae-1fdf-f98f-e0916758e49b
  2. https://hydrogenaud.io/index.php?topic=121732
  3. https://forum.dbpoweramp.com/showthread.php?39459-WMA-Lossless-Encoder-is-BROKEN
  4. https://en.wikipedia.org/wiki/Comparison_of_digital_music_stores
  5. https://en.wikipedia.org/wiki/Codec_listening_test#Results