Hi Leyla,
I connect with high quality HDMI from Swisscom TV Box to AV unit. HDMI to TV.
TV Box is set on Surround Sound. As I said, many programmes show DOLBY D on AV unit (both in original and second language on, for example, FOX TV programmes with dual language options). However, a lot of programmes shown Dolby Digital on information, screen listing but do NOT get Dolby D on AV - I'm attaching a dropbox link to screen grabs from TV and photos of AV Unit (set on AUTO to reflect input from Swisscom TV Box).
https://www.dropbox.com/sh/uvx5r4g9cdfyzks/AACf5lG7occ7137UwbL-85Zka?dl=0
1. Channel 5 HD - Showing Dolby Audio / AV Unit shows Dolby D
2. Channel 4 HD - Showing Dolby Audio / AV Unit shows Stereo
You can see on both that the AV Unit indicates a Dolby Signal (above the words DOLBY D and STEREO) but different response. It is quite strange.
Regards
Mark