This whole HDMI bitrate vs 7.1 uncompressed is driving me nuts?!?! What is the best/correct ...

Im running 7.1 with my Denon 3312CI. Heres the thing... I still use a seperate sammy blu ray player for movies, and lossless, etc. but if Im just using my One for gaming Im told and thinking to use 7.1 uncompressed Right? Right? But I dang well know
that the games are NOT encoded in 7.1 so isnt the 7.1 uncompressed just duplicating the same in each rear as the side?! Id rather go bitrate Dolby then, so my receiver sees this and matrixes the rear correct? Id want my rear matrixed not an identical match
of the side since that would throw depth off...this crap should be simple, as in bitrate uncompressed, and let the receiver do its work. I love DTS, but am also sure the games arent being programmed in DTS either. Can I get some real thkughts from some die
hard theater peeps here please.

:)

 

Cracking sounds when HDMI is set to Bitstream OUT

Regarding the HDMI Bitrate, since the update I have tried switching from 5.1 to Bitrate which has drastically improved the surround sound, but after about 5 minutes the audio completely cuts out. I have tried this several times and while uncompressed stereo,
5.1, and 7.1 always work, Bitrate with Dolby Surround sound much better. Has anyone else had this issue?

 

DTS reverting back to Uncompressed 7.1

Yes dts master audio is the best dts. Not sure which the xbox is doing. Either way uncompressed the audio bitrate is much higher than dts master audio. Which I have tested on my bluray player before comparing dts master vs uncompressed. But master audio
is considered lossless like uncompressed for what it's worth.

 

I don't know if games support 7.1 or not, but I don't think the Xbox would simply duplicate the rears in to the extra two channels. I would think it would be much more likely to simply leave those channels empty if they aren't being used. If you set it
to 7.1 and get sound from the rear surrounds during games, I'd think that means the games support 7.1. But if they are blank and you want your receiver to matrix the audio into 7.1, use 5.1 uncompressed, not Dolby or DTS. Why unnecessarily compress the audio?

 

The setting of 7.1 uncompressed is best because it eliminates both the need for the One to encode the uncompressed multichannel PCM audio to a bitstream and the need for the receiver to decode that bitstream back to uncompressed PCM. I am not sure whether
any Xbox One games have true, discrete 7.1 audio. However, if a game only supports discrete 5.1, I would think the One would (when set to 7.1) expand it to 7.1 by a similar matrix process as your receiver. Alternatively, you could try setting the One to
5.1 uncompressed and see if your receiver can be set to a listening/processing mode that expands it to 7.1 via its own matrix process.

 

The receiver wont decode a thing when it comes over pcm. So we are guessing as to what the one is doing with rear channels in 7.1, thats the problem.

 

The receiver doesn't need to do any decoding with PCM audio, that's the point. PCM audio isn't encoded, it's simply pure, uncompressed audio. That's why it's the best option.

Still, your receiver should be able to matrix 5.1 PCM into your 7.1 speakers using Dolby Pro Logic IIz or something like that. But first, when the receiver is set to Direct and your Xbox is set to 7.1 and you play games, does audio come out of all channels?

 

Yes it does come in from all channels. It would be nice to know what the one does with 7.1 when its not encoded for 7.1?! I guess thats the real question.

 

What happens when you play other 5.1 content, like from a DVD or Netflix? I have a 5.1 setup and whenever I watch stereo content it continues to output 5.1 PCM, but with sound only coming from the fronts, leaving the center and rears blank. I assume it
would do the same in your 7.1 setup; where if the source is 5.1 it would continue to output a 7.1 signal, but leave the rear surrounds blank.

 

I don't think true 7.1 is available yet, but using PCM from the XB1 may decode it similar to Dolby Digital EX, which is 5.1 and then uses surround processing on the Rear Right and Lefts to make up the additional back channels.

Personally, after reading this thread, I'm changing my setting to Dolby Digital 5.1, since I have a THX Ultra 2 Plus. certified receiver. I'd rather my receiver decode the audio as it probably does a better job of processing the stream.

True 7.1 streams use Dolby TrueHD and DTS-HD Master Audio. Dolby ProLogic IIz is 2 channel audio which is processed into 5.1 (not discrete channels). The difference between Pro Logic and IIz is that the rear surround channels use full frequency response
where original ProLogic does not (low end frequencies are kept in the front channels)

 

Dolby Digital EX is 5.1 digital with matrixed rears. Prologic 2 is just a newer stereo version of pro logic. Im going bitstream because I dont trust or know what the one is doing with any extra channels. I want my receiver to decode the bitstream. Until
I know more from microsoft, thats what Im rolling with.

 

I follow that answer up clarifying again...I use my good sammy bluray player for blurays and the lossless dts ma, dolby Hd master soundtracks. Games arent coded that way.

 

Agreed.

To add, since there is no option on the XB1 for Dolby TrueHD or DTS-Master Audio, leads me to believe that its decoding similar to Dolby Digital EX (as I'm pretty sure I've heard the Surround Back channels).

I'm sure the 7.1 option is really for future proofing, and at some point they'll add TrueHD and Master Audio..

But as I write this, raises the question for BluRay playback on the XB1, in which case true 7.1 movies should probably be set for uncompressed 7.1..

 

The Xbox One is still doing audio decoding, even if you select Bitstream. It will decode all audio into PCM and then encode it again into bitstream if you chose to. It's never going to just pass on encoded audio direct from the source. It can't really,
because of all of its audio mixing it has to do. If you're playing a game and snap TV, then it has to mix the audio, which can only be done in PCM. If you're watching a movie and just go to the home screen it has to be able to mix audio. It's always going
to decode everything into PCM. All you're doing by selecting bitstream is making the Xbox re-encode it and your receiver decode it back, it can't gain anything.

If you're worried about what's happening with those extra channels on games, I still think the best option would be 5.1 PCM, then let your receiver do whatever you want. I also don't see the Xbox One adding the ability to output DTS-HD or Dolby TrueHD,
there's just no point in it. It still won't pass it on directly from the Blu Ray, unless they would just have it disable and switch to PCM output anytime any mixing had to be done. The way it works now is fine, it just decodes it into PCM and passes it on.

 

• But koop, ive either lost my mind or not, or something...but you cant apply dolby digital settings or dts settings to pcm signals coming in. Can you?! Bitstream can be adjusted and broken down to a matrixed Dolby Ex, OR DTS-Neo for 7.1 matrix with a capable
  receiver knowing, and pcm isnt adjusted the same way by the receiver. Im pretty dang sure the One is either not making the back channels, or its duplicating each side to the rear channels for the Ones uncompressed settings. I would think that the uncompressed
  pcm is needed for the lossless blu ray streams, but not so much for games...as in we dont know what the one does with setups over 5.1 on games.