Sonnox Fraunhofer Pro-Codec User Manual
Page 38
5.9 HD-AAC
5 THE PRO-CODEC PLUG-IN
The bit meter indicates that there is no activity in bits greater than 24. The input to the
codec is correctly dithered and truncated. The border for the bottom segment is green to
indicate that the dither/truncation is provided internally.
The bit meter will also indicate when you are dithering unnecessarily.
Here a correctly dithered and truncated signal enters the plug-in, but the internal dither is
also applied. One of the operations is redundant, and this is indicated by a red border
around the bottom segment.
HD-AAC 24 bit with
CORRECT dither and truncation prior to the Plug-In. HD-AAC 24 bit
internal dither is
ENABLED.
There is a situation when it is desirable to use the internal dither/truncation, even if the
signal presented to the plug-in input is correctly treated.
This case is when the lossy core has been observed to cause overloads on decode, and
the remedy has been to use the internal
TRIM dB control. The trim will be applied
internally to the plug-in, and any external dithering is not helpful. The signal should be
dithered using the internal dither option.