Originally Posted by sd13
I plugged it into my Samsung q90r and it shows pcm as well. The Dolby digital is grayed out in the sound settings of the tv. I’m not sure if this is a defect or if it is just not capable of outputting 5.1 sound through the tv speakers. I had no trouble outputting 5.1 sound to any of my tv speakers or through the TVs optical output to a Sonos and Bose soundbar with my pioneer receiver.
First, if you see a menu on the Samsung TV that has Dolby listed/greyed out, that is the menu for audio pass-through going OUT FROM the TV via ARC or Optical.
There are two audio settings in recent Samsungs. One is usually called HDMI Audio Setting and the other just Audio Setting (or something equivalent). The former setting for a HDMI input source is the one that tells the upstream what it can send. Typically, the only choices for this setting will be PCM or Bitstream, neither of which will ever be greyed out.
When set to PCM, it asks upstream source in the handshake to decode all codecs and send only PCM and notes it has only two speakers. So an upstream source which honors this handshake (like a recent generation Denon and unlike older receivers that don't really care) will send PCM stereo. When set to Bitstream, the TV says in the handshake that it can take a number of formats undecoded and any number of channels (typically Dolby and DTS will be supported at the minimum but higher end TVs can have more internal decoders).
In this case, receivers like the Denon if working correctly will send undecoded Dolby or DTS multichannel or whatever the TV says it can support. The older receivers will continue to send whatever they were sending before.
The choices in the second setting (greyed out or not) are the formats the TV can send out/pass through via HDMI or Optical to a downstream audio processor. If it receives a Bitstream, it will enable the compatible formats it can pass through and pick the nearest automatically.
Your confusion is probably from the differences in how new receivers/TVs and old receivers/TVs participate in the handshake. The handshake prevents the TV from receiving formats it cannot decode and so just not output any audio. So, all recent receivers participate in the HDMI handshake. If you do find the Bitstream option and turn it on, you MAY need to power recycle the AVR to re-initiate a handshake.
Older receivers may just pass through everything or may have their own setting on what to pass through. The handshake removes the need for manual intervention once you have set up the flow in the pass through mode you would like which typically does not change unless there is equipment change.