DTS bitstream passthrough not working properly when playing DVD

shaftanista · Feb 1, 2019

Hi,

I've got an Xbox One S (European variant - DVD Region 2, Blu-ray Region B), it's fully updated (OS version 10.0.17763.3066) and overall I'm pretty happy with it. It also doubles as a main DVD/Blu-ray player in my home. I recently upgraded to a home theater
setup and discovered that the Xbox behaves a bit weird when playing DVDs with DTS audio tracks.

The specific disc I discovered it with is a
concert DVD of a Polish band; it has three audio tracks, which show up as Polish DD 5.1, Polish DTS 5.1 and Polish DD 2.0. All of them play properly through the Xbox when the "Let my receiver decode audio" option is turned off. When I turn it on, however,
the DTS track - while sounding fine and the Xbox properly identifying it as DTS 754 kb/s - causes the receiver to identify the incoming signal as Dolby Digital. It seems that the Xbox is transcoding the signal even though it's set up to pass it through unmodified.
This happens even if I set the console's audio output setting to DTS bitstream - unless of course I disable the "Let my receiver decode audio" option, but then that's the Xbox decoding the audio and optionally encoding it back to DTS.

Unfortunately, I don't have any other DVDs that would have a DTS audio track to check. But I have some Blu-rays with audio in various flavours of DTS (DTS 5.1, DTS-HD 5.1, DTS Discrete 6.1 and DTS-HD-MA 6.1), and all those are passed through properly, with
the receiver identifying what they really are. So it seems to either be a problem related to this specific disc, or to DVDs in contrast to Blu-rays.

Audio from the same disc is properly identified as DTS when played through my laptop (connected to the same receiver via HDMI), using MPC-HC with bitstreaming enabled in LAV filter settings.

My receiver is Denon AVR-X1500H if that's relevant, and everything is connected through HDMI (Xbox -> receiver -> TV, no ARC involved in this path). I haven't tried using the optical output.

This is of course not a show stopper. I can always set the Xbox to decode the audio and pass it as PCM, the audio quality should be identical. Well, even with the DTS->DD transcoding, I'm unlikely to actually hear the difference anyway. But I found it weird,
it's probably a software bug, so I wanted to report this issue. I hope it will be fixed in a subsequent update.

:)

RKP · Feb 5, 2019

I am new to XBOX and purchased one last week. I am facing similar issues.

(1) Once I configure Dolby Atmos, all audio coming from Xbox is showing as Atmos on the receiver side.
(2) When I use Blu-ray, all DD audios are being recognized by the receiver properly as is DTS audio. The Atmos default issue is only for non-Bluray content.
(3) But when I choose DTS Master-HD 7.1 channel, only 5.1 channel is showing up in the receiver.

As the previous poster mentioned, it is odd we have to choose between DTS and DD when selecting bitstream out and selecting passthrough to the receiver. It is not clear the setting is overridden when passthrough is selected, as I can see DTS from Blueray disk with Atmo selected.

XBF Diego M

Hi there,

Thank you for keeping us updated.

I would recommend submitting a formal bug report through the Insider Hub app, but I'll see if I can provide this to one of my colleagues so they can pass it on to the right people if that is possible.

XBF Diego M

Hi there!

That's an odd issue. It's unfortunate you don't have other DVD's with DTS audio to test out other than the one you have tested. We can't be too sure if it's just that disc but it's possible that this happens with DVD's with DTS audio tracks while connected
through the receiver.

Is your console enrolled in the preview program by any chance? It's possible a preview update could have this software bug, but even if the console is not enrolled I suggest formally reporting this problem to the preview team so they can look into this.
You can report a problem after you download the
Xbox Insider Hub app and hen holding the Xbox button on the controller to pull up the power menu.

XBF Leo G

Hello!

Thank you for posting on the Xbox forums. We will be locking this thread due to it being revived by a new post. If there are any questions, discussions or issues that anyone would like to bring to our attention, please create a new thread. We will be
more than happy to answer any questions or provide solutions for any issues. Thank you again and happy gaming!

Kevin1138

I have had a similar problem in north America however it only happens with DVDs, not Blu-ray’s, and it doesn’t happen with every DVD, just certain ones.

Essentially it’s the same thing though the Blu-ray player app will acknowledge that it’s a DTS stream yet it’s passing it through to my receiver as a Dolby digital signal.

As I said before I have checked many DVDs and this glitch happens with some yet not others. Very strange bug

shaftanista

Thank you for the reply. I managed to make some more tests.

It seems that the Xbox is not transcoding the DTS audio as I originally stated, but rather just not switching the audio tracks properly when it is set to pass the audio to the receiver. I didn't notice because, well, on a concert DVD the two 5.1 tracks are
essentially the same mix encoded with two different algorithms, so it's hard to hear any difference

I authored a simple test disc with an equivalent audio track setup and burned it onto a DVD-RW for testing. Here's an ISO (just a test screen and TTS-generated audio, nothing copyrighted) if you want to take a look yourself [Xbox
One DVD audio passthrough bug test.iso] and here's a
recording of my Xbox playing it (first with the "Let my receiver decode audio" option turned off, then with it turned on, for comparison).

No, my console is not enrolled in the preview program, at least not to my knowledge. Thank you for pointing me towards the Insider Hub app, though. I didn't know what the proper bug reporting procedure was, so I posted on the forums.

BTW, I had some problems posting here; I might have ended up launching this thread several times, because I was getting silent errors from the forums (the browser was just freezing when I was clicking the send button). Sorry about that if it was the case.

EDIT:

I tested some more things:

The problem persists when I connect the Xbox directly to my TV (which is a Samsung UE65MU8002). The TV is perfectly capable of decoding both DD and DTS by itself. The results were exactly the same as with the receiver.
I made another test disc that leaves out the DD 5.1 track, leaving only DTS 5.1 and DD 2.0, both still identifying as Polish. The result is
another peculiar behaviour - the DTS track gets forwarded as DTS bitstream, and I cannot switch to the DD 2.0 track (the DTS track still plays even when the DD track is selected). Everything still works fine when Xbox decodes the audio, though.
The problem also persisted when I changed the language ID of one of the audio tracks in the authoring software (so that the disc has two tracks that identify as English DTS 5.1 and Polish DD 2.0). Still the DD 2.0 track is unplayable as bitstream pass-through.

It seems to conclude that:

The issue is not receiver-specific, as it persists on two different HDMI input devices (receiver and TV).
The issue is not DTS-specific nor language-specific, either. It seems to be a generic bug with DVD audio track switching when bitstream pass-through is enabled.

I guess I'll just stick to letting the Xbox decode the audio for now, at least when playing DVDs. I'd really like to see this bug fixed, though. Should I still file a formal bug report through the Insider Hub, or would you be so kind to let the right people
know of this thread?

DTS bitstream passthrough not working properly when playing DVD