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offset value of DD signal

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    offset value of DD signal

    I am evaluating the new plugin and like it so far but have a couple of questions.

    Is there a function to get and retrieve the current playback offset value for the playing signal?

    For instance when playing DD sources Dolby has a built in mechanism called Dialog Norm that allows the sound mixer the ability to encode in the audio sound track an offset value to reduce the average dialog level. Normal dialog level is considered to be -31DB below reference. So an offset value of -4db encoded results in an average dialg of -27DB below full reference volume of the sound track. Thus this would be a -4db offset encoded in. Some movies have a -2db offset and as with one film recently it was a -6db offset. In short sometimes a sound mixer will use the offset to either create dialog that is much closer in relation to maximum spl level for the loudest sounds in the soundtrack or will create offset values much lower than maximum sounds in the soundtrack to create a larger dynamic range experience in the soundtrack. What the Denon receiver does is takes the offset value and lowers the overal db level by this offset. So in general if the maximum db level for a reference played back recording is 105DB and your receiver is set to play back at full reference volume the offset value of zero would give you a maximum output value of 105db. an offset value of -4db would give you a maximum output level of 101db.

    Why is knowing offset important?

    Ever noticed some movies just play back too soft or too loud? Most likely all things the same the offset value is different reducing the maximum volume of the sournd from say 105 to 101db. And vice versa, if no offset value is deployed the decoded at full reference volume will play back the sound track at a maximum value of 105DB but dialog will be played back a little too high to be comfortable as in this case with lots of DTS sources, I find myself having to reduce the volume about 4db to make the maximum value hit around 101DB like with DD sources with a -db offset and create a consistent dialog from DTS sources to DD sources. My theater is generally setup so that average dialog in the movies is around 79DB or 6db below full reference value.

    Why is retrieving the offset value from the input source important to me?

    By being able to query this offset value in the stream will allow me to use the plugin to make subtle volume adjustments so that dialog and maximum sounds in the soundtracks play back in my theater room at a more consistent level

    I am not sure I remember anything like that in the Denon API documentation, but I will look for it and see if it can be included into the plug-in.

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      web control setup information page on my avr-4810

      on the webgui it is able to pull that information from the receiver. under setup menu/Information/Audio Input signal


      Surround Mode DOLBY DIGITAL +PL2 x cinema
      Input Signal Dolby Digital
      Fs 48kHz
      Format 3/3/.1
      OffSet -4dB

      I opened a telnet connection to the Denon receiver to sniff out what it is receiving and when I hit refresh on the page I get a bunch of responses from SSINFAISFLG,etc

      specifically i think SSINFOAISOFF might show the offset response


        might not need this added anymore as i just finished writing a geturl script to grab the values from the webpage and store them as virtual devices in homeseer. works good so far.