Manual trigger? No, to use the transcoder you need to set the audio to DD output, meaning everything gets transcoded to DD, even DTS. You would have to enter the audio menu settings to switch if you have a DTS video.
For your setup choose one of the following 3 options, assuming you set the extractor's EDID to DD/AC3:
Settings/Audio/Digital output format =
My 4850x arrived today and works like a charm! I have a 2000 era JVC receiver, back from when JVC still made outstanding AVRs. Given the amount of money I'd have to spend today to get an AVR with an analog sound path that is clean enough for DD+ to even make an audible difference over what I have, this is a fantastic solution. All my DD/DTS streams pass through unmolested, and DD+ is transcoded on the fly.
I have to say, Roku doesn't do a very good job of marketing the Ultra. I can see no marketing information on the Ultra that tells people it has a DD encoder built in. In fact, in most marketing information, the only difference you can see between the streaming stick 4k and the Ultra is USB. I wish I had known.
They actually do specifically mention its Dolby decoding capabilities in the Ultra's product specs, though its slightly misleading/incomplete implying it only applies to Atmos, and doesn't mention its passthrough capabilities:
Roku Ultra | The ultimate streaming player | Roku
| Audio features |
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Compare that to the SS4K, which doesn't mention Dolby decoding of any kind and only mentions passthrough:
Roku® Streaming Stick® 4K | Powerful & portable HD & 4K streaming stick | Roku
| Audio features |
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So the information is in their "marketing", though you do have to scroll all the way down to the specs.
Regardless its good you resolved/solved your DD playback compatibility issue using a decoder model - keep in mind:
It says it can decode Atmos, not that it can encode DD. Decoding Atmos to me doesn't imply it can re-encode it to DD 5.1. The ability to decode Atmos could mean simply rendering it in stereo. They should include:
Maybe it's not an issue for most - I don't know how many other dinosaurs like me have what must now seem like vintage equipment that supports DD but not DD+. But there must be enough people for them to include the capability. Might as well draw attention to it. Another bullet point on the features list can't hurt. It's a great capability!
All Dolby decoders can (re)encode to the Dolby capabilities level of the decoder (e.g. DMAT 2.x PCM/Atmos, DMAT 2.x PCM, DD+/Atmos, DD+, DD) and below & of the detected/configured device (e.g. DMAT 2.x PCM/Atmos, DMAT 2.x PCM, DD+/Atmos, DD+, DD) and below - this is by Dolby spec/requirement (assuming a certified Dolby decoder in usage), and has always been true, so it sort of "goes without saying".
Yes, Roku could put that in the marketing/specs, but none of their competitors/etc devices' with Dolby decoders do (e.g. FireTV, Android TV, Google TV, TVs, etc), and some of them are far more detailed in their audio specs, so I wouldnt hold that against Roku, though a clear statement that it has both Dolby Atmos-level decoder & Dolby passthrough capabilities should be sufficient (better would be to list specifically which Dolby/DTS codecs/formats each model supports; best would be the unicorn scenario of listing all the input codecs/formats vs output codecs/formats and all transcoding/conversion scenarios in a nice huge table/chart).
You/others (and myself: though I have Atmos-capable HTS setups, I also have (and maintain for others) legacy DD-only HTS/etc setups) arent a "dinosaur": there is a much much larger installed base of DD-only devices than there are DD+ (and higher) devices, so compatibility exists for that reason alone - the difference between Roku and its competitors is that most Roku models lack Dolby decoders (passthrough only), whereas most/all competitors models include Dolby decoders (no passthrough), giving competitors an advantage when it comes to fuller 5.1 (DD+/DD) compatibility, though a disadvantage when it comes to 5.1 passthrough capabilities.
