Can bitsteaming / audio passthrough be implemented?

[Aspvr]

Is there any chance of audio passthrough being implemented?

I would love to be able to get dolby atmos to my receiver from overwatch and battlefront

Is this possible or are there hardware limitations?

Happy New Year!!

[JimmyJames26]

Idk if this helps but I use optical output from my tv to my steam link for my sound bar and sub woofer.

Steam link ----HDMI--> T.V ----optical cable--> sound bar and sub.

The link supports 5.1 so I'm not quite sure what your question is.

[Aspvr]

I have 5.1 too, thats not what i was asking

[JimmyJames26]

Originally posted by Aspvr:

I have 5.1 too, thats not what i was asking

My bad then!

[Aspvr]

No Problem.
What I Need is to send dolby / dts through the link to my receiver.
Obviously I know that the source needs to be outputting dts or dolby.
I'm not asking for encoding nor decoding quite the opposite I want passthrough.

[DirtyCamper]

Is there a particular reason to ask for dolby/dts? As it usually is meant to be a fallback because a lot of systems can't handle PCM. PCM still delivers the best audio quality on HDMI.
The fallback is intended for those that have no 5.1/7.1 cable set, and just have a toslink cable. Toslink can't go higher than stereo PCM. To have still have surround, the PC has to compress the channels on the fly to dts.
So if you can, use 5.1/7.1 PCM. But If your equipment or game isn't capable of PCM then I fear you you are out of luck.
On the other hand: even if your setup is 7.1 PCM I assume the compression will hurt the phase differences.
To be clear: I've never heard dolby/dts with correct phase shifts, pure stereo PCM with good phase shifts sounds so much better than 5.1. I know that atmos is finally trying to introduce phase shifts as it should have been a long time ago, but that same effect should also be available with a normal 5.1 set and openal (if I am correct).
But streaming of the phaseshifts to the link... I don't know... I fear you will loose it.

Anyway, good luck with it. Hope to hear if you ever got a solution.

[Aspvr]

I understand, and my receiver handles PCM correctly, my intention is not to encode anything,
games that output 5.1 PCM I want to keep that way, but some games like the new battlefront, now come with Dobly Atmos, and I would like to be able to pass that to my recievier/speakers.

Just wanted to know this, before I commit to re-thinking and re-doing my setup.
The link works pretty good. Some artifacts in some games like The Witcher 3, and that it.
But I want Atmos and 4k, I know 4k is not possible with the hardware, but if I could get Atmos in the near future I might stick with the link, if not i will try moonlight or hdmi over ethernet.

Would love some dev input on if its coming or not, no explanation needed, just a yes or a no will suffice.

Thx in advance

[DirtyCamper]

Originally posted by Aspvr:

I understand, and my receiver handles PCM correctly, my intention is not to encode anything,
games that output 5.1 PCM I want to keep that way, but some games like the new battlefront, now come with Dobly Atmos, and I would like to be able to pass that to my recievier/speakers.
<snip>

Heh, as a matter of fact, I just closed my google search for atmos. Seems very interesting, and indeed better than PCM: for those new to it: atmos promises to have a speaker setup agnostic format, in which you can position the streams origin, and the receiver must calculate phase shifting or any other way it is able to do it. It can be done cheap by driving 40+ speakers all over the room, or just 8 speakers with good phase shifting.
I have no idea how it technically is supposed to work, as I can only see it work using PCM for low latency and some 3D positioning.
I really really wonder if it is supposed to do a doppler effect (play a constant sine wave, and move the position from front to back, if it is what the hype promisses, the sine wave should change frequency to the hearer), or if it is more marketing hype.

Anyway, Aspvr, nice question.

[Xjph]

Originally posted by DirtyCamper:

I have no idea how it technically is supposed to work, as I can only see it work using PCM for low latency and some 3D positioning.

There needs to be a Dolby decoder somewhere in the processing stream, as the Atmos stuff for PC is all done within the Dolby TrueHD encoder. Dolby doesn't offer any way to just directly output Atmos as PCM (even though there's no technical reason they couldn't) because then you could use it without a Dolby Atmos branded receiver. :P

[Aspvr]

Originally posted by Vithigar:

Originally posted by DirtyCamper:

I have no idea how it technically is supposed to work, as I can only see it work using PCM for low latency and some 3D positioning.

There needs to be a Dolby decoder somewhere in the processing stream, as the Atmos stuff for PC is all done within the Dolby TrueHD encoder. Dolby doesn't offer any way to just directly output Atmos as PCM (even though there's no technical reason they couldn't) because then you could use it without a Dolby Atmos branded receiver. :P

Excuse mi ignorance, I really don't have enough information to contradict you, but if the game has the option to output Dolby Atmos, wouldn't the game itself encode the sound ? as i understand it, the link captures the sound directly form the game bypassing the sound card (reason why Dolby Live encoding doesn't work for many ppl), but its not the sound card that's encoding the sound its the game (cpu), so it shouldn't be an issue for the link,
unless the link also compresses sound before streaming it.

Having passthorugh would also be useful for ppl who use their pc as their media player.
Only way to enjoy Atmos in blu rays is with passthrough.

I might be very wrong about this, all my conclusions are derived from very light reading.\

[Xjph]

Originally posted by Aspvr:

Excuse mi ignorance, I really don't have enough information to contradict you, but if the game has the option to output Dolby Atmos, wouldn't the game itself encode the sound ? as i understand it, the link captures the sound directly form the game bypassing the sound card (reason why Dolby Live encoding doesn't work for many ppl), but its not the sound card that's encoding the sound its the game (cpu), so it shouldn't be an issue for the link,
unless the link also compresses sound before streaming it.

The game doesn't do the encoding from what I understand, it just adds whatever positional information Atmos uses. The actual Atmos encoding is done by the audio chipset, which according to EA's support page on making Atmos work in Battlefront, requires you to use a sound card with Dolby TrueHD audio processing capabilities and output your sound directly to a receiver that can decode Atmos.

edit: Okay, the page for Overwatch's Atmos implementation has differing information. Maybe it's handled differently by the different games. Overwatch does seem to handle all the Atmos processing in software, but appears to output Atmos for headphones specifically, not for a home theatre system.

So, I guess the TL;DR is that it's really not clearly communicated how Atmos is implemented by each game, and they both use it for different things. Battlefront uses Atmos hardware to directly drive an Atmos capable home theatre receiver, while Overwatch uses Atmos for headphones in software to provide positional audio via stereo headphones.