Editing Speex (section)

==== Complexity (variable) ====
With Speex, it is possible to vary the complexity allowed for the encoder. This is done by controlling how the search is performed with an integer ranging from 1 to 10 in a way that's similar to the -1 to -9 options to [[gzip]] and [[bzip2]] [[Data compression|compression]] utilities. For normal use, the noise level at complexity 1 is between 1 and 2 dB higher than at complexity 10, but the [[Central processing unit|CPU]] requirements for complexity 10 is about 5 times higher
than for complexity 1. In practice, the best trade-off is between complexity 2 and 4, though higher settings are often useful when encoding non-speech sounds like [[DTMF]] tones.