I thought I’d start a thread on this as it is apparent that a few Discs Suffer this issue. From what we know so far:
- It only impacts the ATMOS Track when bit-streaming the audio
- The audio drop out can last from a short break to a full 10sec of no audio (depending on how quickly your HW Equipment takes to resync)
- The original Disc in a HW Player does not exhibit this issue (eg for me an XBOX One S plays it correctly).
- The original Disc also plays fine using PDVD
- It seems to impact players that use ffmpeg (eg JRiver Media Center, MPC-HC)
- NVidia Shield also has the same issue (does Shield use ffmpeg?)
We don’t know for sure what the root cause but so far the summary of the speculation is:
- Decryption Issue with DeUHD : Possible. In my testing comparing the output between DeUHD / makeMKV / AnyDVD each were writing different headers in the M2TS packets (though MakeMKV have confirmed they will update their prog to write the packets with the same values as discussed here3). Maybe it is such an issue at these points
- Mastering Issue : Unlikely. We can all play these discs with dropping the audio on HW players.
- PC based SW Issues : Possible. We are all using the same underlying ffmpeg dll for bitstreaming the Audio. ATMOS support is pretty new on the PC. Given that there is no issue with HW players, it could be a “bug” in ffmpeg handling these streams at this point (if you google ATMOS Dropout you get plenty of recent hits and bugfixes).
- PC based HW / Cable Issues handling “High Bit Rate Atmos” : Unlikely. We all have different HW setups but each have the same issue at the same spot.
Sample: Here is a [URL=“https://ufile.io/kjezf”]40 sec sample[/URL] from a UHD BD with Atmos Track (325MB) where at the 33sec mark the ATMOS track drops out when bitstreaming to an AVR. This can be used for testing to see if your setup has the issue OR if anyone has the skills then please update us. I’ve also posted this in the LAV Forum on Doom9 in the hope the Hendrik/Nevcairel has some comments.
I thought it would be good to consolidate the details below of what Discs (and setups) are impacted.