Dolby Digital pass-through/decoding issues

1st Official Post

    Hi everyone,

    I refer to this kind of setup

    LE8.90 (Intel NUC) => TV (HDMI 2.0) => AV receiver (via optical connection, could not get ARC to work)

    It's setup like this as my AV only supports HDMI 1.4/1080 and I want to have implement 4k this way.

    Viewing video files is ok and audio is passed through this chain just fine.

    I know that streaming Live TV from a tvheadend server prohibits pass-through and that Kodi needs to decode.

    But 5.1 sound does not get through to my speakers.

    I did an additional test with a file where I disabled pass-through manually. Same here, no 5.1 at my speakers.

    If I connect LE via HDMI 1.4 to my AV and stream TV this way, 5.1 sound is ok (still, no pass-through obviously).

    Any suggestions how to trouble-shoot?

    Edited once, last by mbonet (October 4, 2018 at 1:58 PM).

    • Official Post

    The optical out on your TV might be only meant for its internal DVB-S receiver (if it has one). In a little bit I doubt, that a conversion from HDMI to some optical out (Toslink or S/PDIF) will work in that way using external devices.It could probably send the 2 channels to your amp where you might get DolbyProLogic IIx or something like that. But that´s 2ch PCM then and not a conversion from a bitstream coming from HDMI to some optical out.

    ARC is something different which is also able to handle external devices connected via HDMI. But ARC also has to be supported by your AVR. I nearly have the same problem. My AVR also isn´t ARC-capable and if I ever get a 4kTV I have to make my thoughts how to deal with that.

    In my case I probably consider some HDMI spliiter (1 in 2 out). So I´m able to send the audio to the AVR and the video to the TV directly.

    That's right, internal DVB-S or Netflix app deliver sound to the AVR via that link just fine.

    So maybe you're right and the TV can't handle 5.1 PCM from its HDMI input.

    My AVR claims to have ARC implemented, so I need to give it another try. Maybe that's a solution.

    Otherwise I'd need to replace the AVR with a newer one which can handle HDMI 2.0.

    I had this issue. Solved it by browsing my TV settings. Found a setting for the Optical audio output. Had to change it to Dolby Digital. After that I followed the "TV (AC3)" from the guide posted above.