Cobalt Digital FUSION 3G 9931-EMDE 3G_HD_SD-SDI Embedder_De-Embedder - Manual (Page 22)

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9931-EMDE Functional Description
1-18 9931-EMDE PRODUCT MANUAL 9931-EMDE-OM (V1.15)
The 2.0-to-5.1 upmixer can be set to upmix in any of three modes: Always
upmix, Bypass upmix, or Auto enable/bypass upmixing. The Auto upmixing
mode looks at the signal levels on the selected channels and compares them to
a selectable level threshold. It then determines whether or not to generate 5.1
upmixing from the stereo pair as follows:
• If the upmixer detects signal level below a selected threshold on all
three of the selected channels designated as
C , Ls , and Rs , this
indicates to the upmixer that these channels are not carrying 5.1. In
this case, the upmixer produces new 5.1 content generated by the
upmixer.
• If the upmixer detects signal level above a selected threshold on any
of the three selected channels designated as
C , Ls , and Rs , this
indicates to the upmixer that the channel(s) are already carrying
viable 5.1 content. In this case, the upmixer is bypassed and the
channels fed to the upmixer pass unaffected to the upmixer outputs.
The examples in Figure 1-8 show the automatic enable/disable upmixing
function applied to example selected channels
Bus Ch 1 thru Bus Ch 6 . As
shown and described, the processing is contingent upon the signal levels of
the channels selected to carry the new 5.1 upmix relative to the selected
threshold (in this example, -60 dBFS).