ATMOS DCP BAD SOUND ON VIDEO EXPORT

[BKRUGGER]

I'm trying to export a video file from a dcp with Atmos, but I get a terrible sound over the whole film, like some sort of protection noise. Is it possible to avoid it or is it a dolby security mechanism. The client sent me a 7.1 and a 5.1 dcps, I tried to export the 7.1 in various ways, and I~m currently exporting the 5.1 to test. I would like to know if this could be fixed or if I'll have to ask then for a Prores. Thanks!

[carl]

Is it feasible to send me the DCP? carl@dcpomatic.com

[BKRUGGER]

Hey, Carl, thanks for the reply. It's kdm protected.

[carl]

You've got a KDM though, I guess?

[BKRUGGER]

Yes, the client sent me the dcps with the keys for my machine and I'm supposed to export a prores for subtitiling and translation purposes and then reexport a dcp with the subs. The sound of the dcp is ok on player, but when I export the video it has a terrible sound over the film sound.

[carl]

How many audio channels does your exported video file end up with?

Does it help to tick "Mix audio down to stereo" when exporting?

I'm guessing maybe that the ATMOS sync channel is ending up in the output somehow...

[BKRUGGER]

Ok, I'll try it and let you know. Thanks

[Carsten]

You need to edit the channel assignment in the matrix to use only channels 1-6 for 5.1, or 1-6 plus 11 and 12 before you export the audio.

I guess it's not a good idea to exclude certain channels automatically for export.

The player playback matrix by default only maps channels 1-6, that's why you don't hear the ATMOS timecode.

- Carsten