18.Lowpass Filter Control; 19.Lfe Lowpass Filter Control - evertz 7812UDXD Series Manual

7800/7700 MultiFrame Manual
7812UDXD Series 3G/HD Up/Down/Cross Converter with Simultaneous Dual Format Outputs and AES I/O
6.31.2.18. Lowpass Filter Control
This control allows the user to author the Lowpass Filter Control metadata for the Dolby bit-stream. This
parameter determines whether a lowpass filter is applied to the main input channels of a Dolby Digital
encoder prior to encoding. This filter removes high frequency signals that are not encoded. At the suitable
data rates, this filter operates above 20 kHz. In all cases, it prevents aliasing on decoding and is normally
switched on. This parameter is not passed to the consumer decoder. The Lowpass Filter Control drop
down menu provides the following options:
Disable
Enable
6.31.2.19. LFE Lowpass Filter Control
This control allows the user to author the LFE Lowpass Filter metadata for the Dolby bit-stream. This
parameter determines whether a 120 Hz eighth-order low-pass filter is applied to the LFE channel input of
a Dolby Digital encoder prior to encoding. It is ignored if the LFE channel is disabled. This parameter is
not sent to the consumer decoder. The filter removes frequencies above 120 Hz that would cause aliasing
when decoded. This filter should only be switched off if the audio to be encoded is known to have no
signal above 120 Hz. The LFE Lowpass Filter Control drop down menu provides the following options:
Disable
Enable
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Filter is disabled.
Filter is enabled.
Filter is disabled.
Filter is enabled.
Revision 1.1.1