Difference between revisions of "Windows Media Audio"

From Hydrogenaudio Knowledgebase
Jump to: navigation, search
Line 1: Line 1:
WMA is Microsoft's compressed audio format. It's actually a generic name for several codecs that can be used inside it:
+
'''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==
+
  
 +
== 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.
 
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]].
+
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.
 
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==
+
 
+
 
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 rate]]s)
 
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 rate]]s)
  
Line 18: Line 15:
 
These days, Microsoft is pushing the Pro codec for inclusion in the next generation DVD standard as standard audio format.
 
These days, Microsoft is pushing the Pro codec for inclusion in the next generation DVD standard as standard audio format.
  
 
+
== Windows Media Audio Lossless ==
==Windows Media Audio Lossless==
+
 
+
 
This is the matematically [[lossless]] codec in the Windows Media family. It's a welcome addition since it was the first lossless codec backed up by a major player in the multimedia compression field. Compression efficiency-wise, it's on par with [[WavPack]] high and between [[Monkey's Audio]] fast and normal.
 
This is the matematically [[lossless]] codec in the Windows Media family. It's a welcome addition since it was the first lossless codec backed up by a major player in the multimedia compression field. Compression efficiency-wise, it's on par with [[WavPack]] high and between [[Monkey's Audio]] fast and normal.
  
 +
== 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.
  
==Windows Media Audio Voice==
+
== Additional Reading ==
 
+
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 20kbps.
+
 
+
 
+
==Additional Reading==
+
 
+
 
* [http://www.microsoft.com/windows/windowsmedia/9series/codecs/audio.aspx Description of Windows Media Audio codecs] at Microsoft
 
* [http://www.microsoft.com/windows/windowsmedia/9series/codecs/audio.aspx Description of Windows Media Audio codecs] at Microsoft
 
* [[Lossless_comparison|Lossless Codec Comparison]] by Rjamorim
 
* [[Lossless_comparison|Lossless Codec Comparison]] by Rjamorim

Revision as of 16:22, 13 June 2007

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 matematically lossless codec in the Windows Media family. It's a welcome addition since it was the first lossless codec backed up by a major player in the multimedia compression field. Compression efficiency-wise, it's on par with WavPack high and between Monkey's Audio fast and normal.

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