Editing Variable bitrate (section)

{{Short description|Files in which the rate of bit transmission is non-constant}}

'''Variable bitrate''' ('''VBR''') is a term used in [[telecommunications]] and [[computing]] that relates to the [[bitrate]] used in sound or video encoding.  As opposed to [[constant bitrate]] (CBR), VBR files vary the amount of output [[data]] per time segment.  VBR allows a higher bitrate (and therefore more storage space) to be allocated to the more complex segments of media files while less space is allocated to less complex segments.  The average of these rates can be calculated to produce an [[average bitrate]] for the file.

[[MP3]], [[Windows Media Audio|WMA]] and [[Advanced Audio Coding|AAC]] audio files can optionally be encoded in VBR, while [[Opus (audio format)|Opus]] and [[Vorbis]] are encoded in VBR by default.<ref name="hydrogen">{{Citation |title=Variable Bitrate |url=http://wiki.hydrogenaud.io/index.php?title=VBR |year=2007 |publisher=Hydrogenaudio |format=knowledgebase |access-date=2009-09-30 |archive-date=2014-07-06 |archive-url=https://web.archive.org/web/20140706173623/http://wiki.hydrogenaud.io/index.php?title=VBR |url-status=live }}</ref><ref name="afterdawn">{{Citation |title=Glossary |url=http://www.afterdawn.com/glossary/terms/vbr.cfm |contribution=VBR |publisher=AfterDawn |access-date=2009-09-30 |archive-date=2010-01-28 |archive-url=https://web.archive.org/web/20100128060334/http://www.afterdawn.com/glossary/terms/vbr.cfm |url-status=live }}</ref><ref name="audacity">{{Citation |title=Variable bit rate |url=http://wiki.audacityteam.org/index.php?title=Variable_bit_rate |publisher=Audacity |format=wiki |access-date=2009-09-30 |archive-date=2009-09-08 |archive-url=https://web.archive.org/web/20090908005152/http://wiki.audacityteam.org/index.php?title=Variable_bit_rate |url-status=live }}</ref> Variable bit rate encoding is also commonly used on [[MPEG-2]] video, [[MPEG-4 Part 2]] video ([[Xvid]], [[DivX]], etc.), [[MPEG-4 Part 10]]/H.264 video, [[Theora]], [[Dirac (codec)|Dirac]] and other video compression formats.{{citation needed|date=September 2014}} Additionally, variable rate encoding is inherent in [[lossless compression]] schemes such as [[FLAC]] and [[Apple Lossless]].{{citation needed|date=September 2014}}