The HiFiBerry Digi/Digi+ can output 5.1-channel DTS and Dolby Digital soundtracks to a receiver that can decode it. Note that this feature isn't officially supported by us and we can't guarantee that it will work in any installation.
To enable this you have to do the following steps:
1. Make sure the HiFiBerry Digi is configured correctly. You can use our OpenElec guide for this.
2. Enable the sound output to the HiFiBerry Digi. To do this, go to Settings/System/Audio output and select the HiFiBerry Digi as the audio output device.
3. Now you still have to enable DTS/Dolby Digital passthrough. You need to enable the expert settings first (in the lower left). After switching to expert mode you have much more options that you can configure. You now need to enable passthrough and also enable “Dolby Digital capable receiver ” and “DTS capable receiver”.