Variable bitrate (VBR), or less commonly variable bit rate, 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 is calculated to produce an average bitrate for the file that will represent its overall sound quality.
MP3, WMA, Vorbis, and AAC audio files can optionally be encoded in VBR. Variable bit rate encoding is also commonly used on MPEG-2 video.
Pros and cons
The basic argument for using VBR streams is quite simple and compelling — it produces a better quality-to-space ratio compared to an equivalent CBR algorithm.
As of December 2006, almost all mp3 devices fully support VBR encoded files. Devices that support only CBR encoded files are becoming increasingly difficult to find.
Early VBR algorithms occasionally introduced audible artifacts when encoding monotone or minimal tones (for example audiobooks and acoustic music). These artifacts often mimicked a "digital chirp" during the quiet portions of the song or when there was only speaking. As VBR encoding algorithms have improved, these problems have been resolved in subsequent generations of the VBR standard.
and yes according to this info it is better, good luck
VBR support is now included in the Apple iPod, Creative Zen, iRiver Clix, and Microsoft Zune.
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