This post relates to issues when bitstreaming from HTPC via HDMI to an AV Reciever with an Nvidia GPU handling the audio via HDMI.
Nvidia driver later than 355.60 does not work (at least up to 368.22 where I had issues, but likely also after that)
Previously this year both Dolby TrueHD and DTS HD had been working for me.
After that a windows driver update was installaed by windows update for my Gefore GTX550 and I did not really notice any issues, but then I mostly watch std DD and DTS movies and dont look to much on my AVR display
Yesterday I was going for Atmos to see if that worked and noticed that DTS HD was seen by my AVR as std DTS
and DTS HD gave an error prompt in MPCHC that it couldnt recoginze the audio format.
Hence i uninstalled MPCHC, LAV filters and installed the latest version. No progress.
Tried resetting MPCHC and LAV and redoing the setup, but same issue.
Started doubting myself and googled for hours on issues with Atmos, be it MPCHC, non compliant GPU, LAV filters or any other issues.
After spending allmost 10 hours I found BELOW post on an Nvidia forum. The guy has experienced the same thing and was right on the money with the solution but Nvidia did not want to recognize the issue, You can read the 3 pages where this guy even struggles with forum members which I dont understand since he was really just looking for answers and was way more knowledgeble than many of the repliers. Anyway.
- I look at my driver version and saw that I had version 368.22 installed for my GTX 560 (nvidia package version). Poster above had a GTX960 so it does not seem related to a single card.
There was also another poster with the same issue but with GT740 under Windows 8.1 and 980TI under Windows 10.
- According to above poster, he had found that the last driver that allowed TrueHD and DTS-HD to work was version 355.60 (but he had other issues with displaying 4K with that driver)
2 resolutions to the issue were mentioned in the thread.
- Nvidias solution (after a lot of support talk and Nvidia even askin poster to contact Microsoft for the issue
) was to slightly lower the resolution of the display and that would enable TrueHD and Atmost once again. For this guy it seemed to do the trick, but who wants to turn down resolution for the display really?
For me, it didnt matter if I went all the way down to 720p 30Hz - audio formats were still broken.
- So I made a quick test according to posters proposal and rolled back video driver from device manager. That did not help.
Then I rolled back the High definition audio driver and BAM - suddenly the DTS-HD and Dolby True HD encoded formats re-appeared under "Playback devices - tab playback - my reciever - tab supported formats" as in attached image. Also Atmos worked like a charm
I then updated my Nvidia driver package to 355.60 which the poster above found to be the latest working one and the audio was still working as it should (also 3D H-SBS H-OU was working)
I hope that this will help somebody, it sure helped me after a sleepless night.
Kudos to "altoiddealer
" who found this (in my opinion) hard to find bug which falls back on Nvidia