Hi,
Soon I will be having a new setup, and I am curious what are the options I have related to audio.
I (will) have the following hardware
- home theatre receiver (Samsung HT-D6750W) that supports DTS-HD but only HDMI 1.x
- htpc with radeon 460 (win10, 4k, 10 bit, etc.)
- LG C7 (4k, hdr, etc.) with HDMI 2.0
Since I would like to output 4k video, I cannot connect the htpc to my receiver with HDMI, since I will lose the 4k capabilities.
So the htpc will be connected to the TV directly.
To get the audio to the receiver there seems to be two options:
1) use the Audio Return Channel HDMI connection from TV to receiver
2) use SPDIF to connect htpc to receiver
Is it correct that if I would use passthrough in Kodi for DTS-HD neither option would work?
Neither ARC nor SPDIF supports DTS-HD, right?
So, there is no way to let the receiver get DTS-HD to let it decode there, right?
That would be a bit dissapointing, because my htpc has a weak CPU.
What would happen if I don't use passthrough in Kodi?
I read that Kodi will then decode the DTS-HD audio in software into PCM.
What happens with this audio stream in the two cases above?
My guess is that sending it over SPDIF probably works fine and I have surround audio and everything.
And what about ARC? Will that work?
You are correct, that neither ARC, nor S/P-DIF ist capable of DTS-HD or TrueHD.
I am not sure about this, but there are HDMI-Splitters on the market. If I look at them, it seems as if the get one input (HTPC) and two outputs:
- one to TV
- one to Receiver
But then again I cannot say whether 4K or HDR will be lost. Also it the receiver could perhaps refuse to read the DTS-HD audio if the Splitter sends an actual HDCP 2.2 signal to it. So this would only be an option, if somebody can confirm this and recommend the specific device, which he tested.
If LibreELEC was used as the OS, there would then be no HDCP issues, but you would not get 4K Netflix either.
If you want 4K Netflix and DD+ audio you need to upgrade an AVR to support HDCP 2.2 / HDMI 2.0
All the rest is speculation an experimentation.
If your home theatre receiver is HDMI 1.4 it is good enough for 4K @ up to 30fps Video
ie. 4K movies
If you just select DTS passthrough in Kodi you will get the lossy 5.1 DTS core from DTS-MA audio, which can be sent over ARC or SPDIF. Trouble is how does the TV process 5.1 DTS audio ?
http://kodi.wiki/view/Audio_troubleshooting
Thanks for your confirmation regarding HD audio on S/P-DIF and ARC.
Do you know anything about the (multi-channel?) PCM stream that Kodi would send on S/P-DIF or ARC?
I have one other thought. I have a HDMI 1.4 connection on-board (APU), but also a HDMI 2.0 connection on the Radeon 460. Will it be possible with Kodi to send the audio on another HDMI connection than the video?
(2017-04-06, 11:06)SmellyCat Wrote: [ -> ]Thanks for your confirmation regarding HD audio on S/P-DIF and ARC.
Do you know anything about the (multi-channel?) PCM stream that Kodi would send on S/P-DIF or ARC?
ARC and SPDIF are not capable of carrying multichannel PCM.
ARC and SPDIF are limited to PCM 2.0/DD/DTS (though not all ARC and SPDIF output implementations support DTS ISTR)
I'd think of ARC as a SPDIF connection going the 'wrong way' down an HDMI cable. It was added on long after the main HDMI spec was standardised, to 'solve' the Smart TV audio issue. (Where a Smart TV connected to an AVR couldn't simply send the audio from internal TV player apps to the amp rather than the TV speakers)
ARC and SPDIF are limited to DVD-quality audio - they are only really capable of 1.5Mbs bandwidth I believe. This isn't enough for more than a 2.0 PCM 48k connection, or DD/DTS at DVD bitrates. You need a full HDMI audio connection for PCM 5.1/7.1, Dolby True HD, DTS-HD MA/HRA and I believe DD+. (Full bitrate HDMI audio is carried over the same data paths and pins as the video signal, with the audio being carried in horizontal and/or vertical blanking periods I believe)
(2017-04-07, 10:37)noggin Wrote: [ -> ]ARC and SPDIF are limited to PCM 2.0/DD/DTS (though not all ARC and SPDIF output implementations support DTS ISTR)
That's a dissapointment that SPDIF does not support any HD audio. It makes you wonder what they are doing making all these audio formats, yet have no way to transmit them to your receiver.
I was hoping my on-board HDMI output could still be used for audio. Unfortunately Windows 10 reports it as "unplugged" after I added my Radeon 460.
(2017-04-07, 21:54)SmellyCat Wrote: [ -> ] (2017-04-07, 10:37)noggin Wrote: [ -> ]ARC and SPDIF are limited to PCM 2.0/DD/DTS (though not all ARC and SPDIF output implementations support DTS ISTR)
That's a dissapointment that SPDIF does not support any HD audio. It makes you wonder what they are doing making all these audio formats, yet have no way to transmit them to your receiver.
Eh? HDMI has been the standard AV interconnect for about nearly 10 years now. HDMI carries HD Audio (in the right direction down cables) with no problems, as well as multichannel PCM. It arrived around the same time as the PS3 and Blu-ray / HD-DVD drives and HD TV broadcasts in Europe.
SPDIF dates back to the 90s (possibly even the late 80s?) - long before HD Audio was 'a thing'.
If you have an HDMI amp, you usually just route your HDMI video output through your amp en-route to your TV. ARC is really only there to route audio from internal apps on your TV, as well as your TV's internal tuners.
(2017-04-07, 21:54)SmellyCat Wrote: [ -> ]I was hoping my on-board HDMI output could still be used for audio. Unfortunately Windows 10 reports it as "unplugged" after I added my Radeon 460.
It should work but you have to enable it as a second display, even if you're only using it for audio.
(2017-04-08, 00:35)noggin Wrote: [ -> ]If you have an HDMI amp, you usually just route your HDMI video output through your amp en-route to your TV.
Unless your receiver is not HDMI 2.0, which I expect will be pretty common for people just buying a UHD television.
You would lose HDR and such.
(2017-04-08, 02:47)Luke M Wrote: [ -> ] (2017-04-07, 21:54)SmellyCat Wrote: [ -> ]I was hoping my on-board HDMI output could still be used for audio. Unfortunately Windows 10 reports it as "unplugged" after I added my Radeon 460.
It should work but you have to enable it as a second display, even if you're only using it for audio.
Thanks for the suggestion. I took another look at things just now and I suspect that the 2nd AMD Digital Display Output, that is unplugged, is unlikely to be the on-board HDMI output, because the on-board display device is not longer present in the device manager. Could it be the Display Port on the Radeon 460? What about if I buy a Displayport to HDMI adapter and connect this to the receiver? Would that work?
(2017-04-08, 11:47)SmellyCat Wrote: [ -> ] (2017-04-08, 00:35)noggin Wrote: [ -> ]If you have an HDMI amp, you usually just route your HDMI video output through your amp en-route to your TV.
Unless your receiver is not HDMI 2.0, which I expect will be pretty common for people just buying a UHD television.
You would lose HDR and such.
Yes - and 2160/59.94p. That is definitely a use-case where dual HDMI outputs are needed for HD Audio - and I believe it is possible (though not always easy)
I'm in a similar situation - but have decided the only really sane course of action is to upgrade my AVR longer term. ARC and SPDIF connectivity are red herrings in this area. SPDIF is a relic from the 90s, ARC is a solution to a different problem (Smart TV app/Tuner audio to AVR connectivity)
I have been using a displayport to HDMI converter to send audio (and video) from the HTPC to the receiver. And a direct HDMI connection to send video to the 4K TV.
I needed to do a bit of fiddling, but in the end I managed to set up multidisplay setup in Windows 10, where Kodi is on the 4K display.
It works in about 95% of the times I start the HTPC. Sometimes I need to restart the HTPC, because the TV didn't detect any signal.