Lots of devs having audio corruption problems on Gear VR...

It would seem that there's some kind of audio corruption affecting Gear VR. It seems particularly severe when using a bluetooth audio device for output, but in our experience it still happens sometimes even with wired headphones or built-in speakers. With speech audio in particular the problem manifests as a very obvious 'robot' voice - slowed down, pitched shifted, slurred kind of thing.
I've logged a bug with a repro project (case 758969). The project is very simple (no OVR/OSP plugin, single audio source in scene). With this project, I get corruption 100% with bluetooth audio, but critically it's the same corruption we've experienced without bluetooth, and I only made the bluetooth connection after googling around. A response from Oculus support mentioned in the thread linked below said...

"So I contacted Oculus support and here is reply they gave me in regards to this problem:
"There currently isn't a work around for this as we've seen some compatibility issues with bluetooth headsets and plugged in peripherals. Sorry about that!""

... but we're seeing it happen on devices without any peripherals apart from the GearVR headset itself.

Is there any up to date info on this problem? My notes...
- Only happens on Gear VR builds. Non-VR builds on the same device (S6) are fine.
- Happens 100% for me using a bluetooth audio device + Gear VR.
- Also happens at reduced frequency - but definitely does still happen - using wired headphones.
- Can often be fixed when it happens by powering the S6 down and restarting, but NOT if happening with a bluetooth device.
- I can only find other mentions of similar problems for other Unity devs. Can't find a single non-Unity mention of similar audio corruption.
- In our full product we use wwise for some of our audio. Even when unity standard audio is corrupt, wwise audio output is fine.

A few discussions which seem like the same problem, based on descriptions of the type of audio corruption...

https://forums.oculus.com/viewtopic.php?t=28184
http://www.landsendgame.com/customer-support (last entry on the FAQ)
http://forum.unity3d.com/threads/gear-vr-and-bluetooth-headphones-issue.357285/

The Oculus forum thread also mentions that Dead Secret (also Gear VR, also made with Unity) used to have a similar or identical problem but that it has been fixed by them - in v1.2 looking at their release notes. Related?

Anyway - enough rambling. This is a pretty big issue for us, even at the reduced prevalence with non-bluetooth audio, so any info greatly appreciated.

Thanks

Andrew

 

Looks like plenty of people are reporting this as a non-VR issue as well, which is interesting. A couple of seemingly relevant extra points...
- There are complaints from non-VR people about audio problems being associated with the use of the Android audio fast path. These seem to centre about custom ROMs falsely advertising fast path support, and also complaints about it with bluetooth devices. However I know that it has happened for us with stock S6 without bluetooth - but only on Gear VR builds.
- However in my experience VR makes a crucial difference on the same device. If I'm running a non-VR build it's fine. Maybe Unity switches something about the audio path internally for Gear VR? As I said I can repro the problem with 'vanilla' Unity Gear VR support (no OVR/OSP).
- Another developer had a Gear VR app which was affected but which was fixed with an update. I asked them what change fixed it - it was the bump to Unity 4.6.9p3. The release notes advertise "Android: Audio - Disabled Fast Path for GearVR". No Unity 5 patch releases around the same time seem to advertise a similar change, and we appear to still have the problem.
- Some people say that the problem only appeared for them in Unity 5.2. I'm very sure we saw the problem in 5.1 - but that was using the legacy Oculus OSP plugin so it may have been behaving differently internally.

So it looks likely that the problem is associated with fast path, and that the differences between VR/non-VR builds and the effect of bluetooth audio output are probably very relevant.

Andrew

 

Hi Yury

Thanks for the reply. We're happy to help if we can. We're very much Gear VR biased - we have 15 devices split across S6, S6 Edge, Note 4 (both Snapdragon and Exynos flavours) and Note 5. Our app (VTime) is heavily VoIP driven so we're very incentivised regarding both audio latency and this audio corruption problem. We've had persistant issues with the audio corruption without bluetooth. I'd say that although we can't create a 100% repro case without bluetooth, the 10% incidence is about right - although it does seem to vary.
- We have an indication from testing that it seems to happen more often on some devices. One report was 'it seemed to be that if I had a particular device I'd know that I'd get it about 1/3rd of runs. If it happened I'd just re-run and it might be fixed'.
- I'm going to see if there's any difference between S6/Note4 Snapdragon/ Note4 Exynos, but I guess you probably know already.
- Having heard audio corruption both via bluetooth and 'raw', I'll reiterate that it seems to sound identical. Perhaps finding the root cause of the bluetooth problem will be all that is needed to fix the rest.
- If there's anything more involved we can do, let me know. For example - you could give us a custom Unity build which injects extra diagnostics into the audio code if that would help. We can run with it and point you at cases where corruption did and did not happen.

Thanks

Andrew

 

I just got my Gear VR in the mail yesterday, so I don't have much to add yet except that I'm experienced audio corruption over bluetooth with my S6 with most, if not all of the published apps available for it - Land's End, Darknet, that ocean sim I can't remember the name of. (Seems to go away when not using bluetooth, to clarify.) I actually thought the audio corruption was intentional with Land's End and the audio was designed to just sound like static throughout the whole game, and then I tried that tactical boardgame sim and heard corrupted voice clips. Not sure if all of these are made with Unity although it wouldn't surprise me. I'll update with more once I have time to build and try out my own apps a bit.

 

I had this issue with Unity 4.6 and the Android SDK for Android 4.4.
Every audio I had included in a build for GearVR with this setup it was totally broken. The audio played but it was like someone played the audio fast forward, higher pitch and played double. I had to build the apps on another PC after a few days of research why this was happening on my own PC. I reinstalled everything for this setup to build correctly, but nothing worked. Switching to Unity 5.1 fixed it for me, I had to do it anyway. Since then I did not experience anything like this error. But I hardly update my Android SDK to avoid such unknown bugs, and that seams to work out very well. Since then I test everything double to avoid such things when I have really close deadlines.

Currently using Unity 5.3.0f4 with Android 4.4 to build and updated by SDK last time about 1 month ago. Building for GearVR Note4 and S6 without issues.

Why the whole audio issues happened for me on Unity 4.6, I never found out.