 Unlike
MP3 audio, the Ogg Vorbis format is not measured in kilobits per
second (kbps), but on an arbitrary scale of 0 to 10, called "quality."
This change in terminology was brought about by a tuning of the
variable-bitrate algorithm that produces better
sound quality for a given average bitrate, but which does not adhere
as strictly to that average as a target. This
new scale of measurement is not tied to a quantifiable characteristic
of the stream, like bitrate, so it's a fairly subjective metric
that provides a more stable basis of comparison to other codecs
and is relatively future-proof. For now, quality 0 is roughly equivalent
to 64kbps average, 5 is roughly 160kbps, and 10 gives about 400kbps.
Most people seeking very-near-CD-quality audio encode at a quality
of 5. The default setting is quality 3, which at approximately 110
kbps gives a smaller filesize and significantly better fidelity
than .mp3 compression at 128kbps.
You may see Ogg Vorbis quality settings on our pages listed as "vbr",
and the appropriate value (i.e. 4.0 vbr.) |
A
selection of MP3 files have been encoded at higher bitrates, thus
producing even better audio performance. However, the trade off for
the improved quality comes in the form of larger file sizes resulting
from less compression. These "HQ" versions are very near
CD-quality.
