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| -rwxr-xr-x | manual/configure_rockbox/sound_settings.tex | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/manual/configure_rockbox/sound_settings.tex b/manual/configure_rockbox/sound_settings.tex index 2cf4c4e064..828bdacd5a 100755 --- a/manual/configure_rockbox/sound_settings.tex +++ b/manual/configure_rockbox/sound_settings.tex @@ -385,3 +385,31 @@ is similar to ``Q'' in the Graphical EQ). filters, and High Shelf, the peaking filters are not currently operational.} } + +\opt{SWCODEC}{ +\section{Dithering} +This setting controls the dithering and noise shaping functionality of Rockbox. + +Most of Rockbox' audio file decoders work at a higher bit depth than the 16 bits +used for output on the \daps{} audio connectors. The simplest way in which to +convert from one bit depth to another is simply discarding all the surplus bits. +This is the default behaviour, and adds distortion to the signal that will +vary in character along with the desired sound. + +Dithering adds low-level noise to the signal prior to throwing away the surplus +bits, which gives the resulting signal a uniform noise floor which is +independent of the signal. Most people find this noise preferable to the +time-varying noise heard when not performing dithering. + +After dithering, noise shaping is performed. This basically just pushes the +dithering noise to the parts of the frequency spectrum humans cannot hear so +easily. In Rockbox' case, some of the noise is pushed up to above 10 kHz. + +This setting will be put to its best use when listening to dynamic music with +frequently occuring quiet parts, classical music being a typical example. It is +worth noting that the effects of dithering and noise shaping are very subtle, +and not easily noticable. + +Rockbox uses highpass triangular distribution noise as the dithering noise +source, and a third order noise shaper. +} |