Internal buffer sizes, Gui controls, 2 internal buffer sizes – Sonnox Fraunhofer Pro-Codec User Manual

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9.1 Plug-In

9 SPECIFICATIONS

CPU Use

All codecs are mathematically intense (some more than others), and some have significant

latency as a result. The user can take advantage of advances in CPU power in modern
computers if appropriate, but can also use the plug-in extensively with older and possibly
lower-powered computers by selecting fewer codecs simultaneously.

In particular, the HD-AAC lossless codec creates a heavy CPU load. High sample rates
exacerbate this situation; for example, without a powerful CPU, the HD-AAC codec might
cause a prohibitively high CPU load at 192 kHz.

All codecs that are added to the

Codec List are always active, in order to report

accurately the NMR signal and potential overload state. This is irrespective of which
codec is selected for monitoring. Remember that this requires both encoding and
decoding of the signal in real time. Thus it is possible to have dropouts with an
underpowered CPU if several highly intensive codecs are active simultaneously.

Online recording will add to the CPU activity (and file-handling activity).

Offline encoding and decoding are CPU-bound, not real time bound.

The graphical area is not CPU-intensive, and should not cause performance problems

even on older CPUs.

9.1.2 Internal Buffer Sizes

Additionally, for most codecs, the plug-in uses internal buffer sizes of 1024 for up to 48

kHz operation; 2048 for greater than 48 kHz up to 96 kHz operation; and 4096 for sample
rates higher than 96 kHz. We recommend that the buffer sizes of the sound card, and
thus of the host application, are set to match these figures.

Buffer sizes for the HE-AAC and HE-AACv2 codecs are twice these figures (so 2048 for
up to 48 kHz operation; 4096 for greater than 48 kHz up to 96 kHz operation; and 8192 for
sample rates higher than 96 kHz).

If the buffer sizes are not matched, there will be an inefficiency in the data transfer, and in
some applications this leads to uneven CPU behaviour.

9.1.3 GUI Controls

Input Meter

0 dB – -63 dB

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