On my Roku TV (2020 TCL 5-Series, software version 9.4.0), in the Audio settings, the "Auto Passthrough" option only works over HDMI ARC/eARC.
My request: Modify the current "Auto Passthrough" option to enable Dolby Digital/DTS passthrough over the Roku TV's optical audio connection. (Or, if this is not possible, add an additional setting for auto-passthrough of PCM/Dolby Digital/DTS over the optical connection.)
Background: My audio receiver only has non-ARC HDMI ports, so I need to send audio from the Roku TV to the audio receiver with an optical connection. A Dolby Digital signal should be sent to the receiver when the audio source is 5.1-channel/Dolby Digital, and a PCM signal sent to the receiver when the audio source is 2-channel (which enables the receiver to up-mix the audio to 5.1 using Dolby Pro Logic II). To achieve this, I need to manually switch the audio setting to "Dolby Digital" to get 5.1 sound from 5.1 sources such as Netflix, and switch back to "PCM-Stereo" to get a 2-channel signal from 2-channel sources such as YouTube. If I leave the "Dolby Digital" setting selected for 2-channel sources, the Roku TV will output a Dolby Digital signal with sound only to the front speakers, and an "empty" sound signal to the other speakers, which means that the receiver cannot detect a stereo signal and upmix it to 5.1 using Dolby Pro Logic II.
