Potential DCP issues (file system, audio channel order)

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Manuel
Posts: 2
Joined: Wed Jun 24, 2020 4:30 pm

Potential DCP issues (file system, audio channel order)

Post by Manuel »

Hi,

After a bit of trial and error, I seem to have made a working DCP copy of my first feature. As we have a small test screening this weekend to see if everything works in a cinema environment, I wanted to check in and ask for help on some uncertainties that I have faced:

- with easydcp player, everything seems fine, hash checks check out, however there is a "code 11" warning, and there doesn't seem to be any way for me to find out what means ;)
- when checking the DCP in Resolve, I'm getting some strange mixed results: there doesn't seem to be audio on the copy that I transferred to an EXT2-formatted drive (the 5.1 clip is shown, but is empty). But I did have the audio at least once. On the NTFS drive that I created just in case, the audio is there. However, Resolve seems to have switched LFE and C channels, with LFE being on top of the center channel when I check "display individual audio channels" in the 5.1 clip... I understand from this post https://lowepost.com/forums/topic/367-5 ... ed-places/ that this might be a Resolve issue, since I definitely mapped the tracks in DCP-O-Matic correctly. Playback of the DCP in Resolve stutters a bit from the NTFS drive
- finally, DCP-O-Matic itself seems to have problems opening the DCP copied to the ext2 drive (could not open mxf file for reading, error -101) but is doing fine with the DCP copied to the NTFS drive :D

I'm using Paragon extFS and NTFS drivers and I'm kinda guessing that (all) these potential glitches are due to file system management issues and the DCPs are fine, but wanted to make sure if anyone had similar experiences and possible suggestions.

(I'm on an iMac with latest DCP-O-Matic version)

Thanks for your help!

Carsten
Posts: 1596
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Potential DCP issues (file system, audio channel order)

Post by Carsten »

Paragon is known to work flaky with direct file access. I wouldn't use it for more than a straight copy between discs.

NTFS is fine (make sure all DCP discs have an MBR partition table, not todays default GUID/GPT partition scheme). The Mac disc utility offers all necessary choices when partitioning a disc.

I prefer Tuxera NTFS for writing to NTFS discs (it also allows formatting/creating NTFS discs). It comes free with some portable Toshiba drives, but even as a direct buy, it is inexpensive.


Do not care much about playout channel order/hardware/interface - it must be correct in the MXF file. To assure this, load the audio mxf of the final DCP into an audio editor. Audacity with the FFMPEG plugin can read DCI audio mxf directly. You will see a very typical audio plot, and swapped channels can usually be tracked down easily. You can also quickly mute/solo individual channels for a listening test.

- Carsten

Manuel
Posts: 2
Joined: Wed Jun 24, 2020 4:30 pm

Re: Potential DCP issues (file system, audio channel order)

Post by Manuel »

Hi Carsten,

Thanks a lot for your reply, that already puts my mind at some reasonable ease :)

Checked the audio mxf with Audacity and the center track is clearly the third, so that seems to be a weird Resolve glitch then.

I'll check out Tuxera!

/edit: was able to verify that the NTFS drive has been formatted with MBR -- nerd muscles got a bit rusty

/edit2: just wondering if there are any further thoughts on this "Code 11" thing from easydcp player -- since otherwise everything seems to work out fine :D
Last edited by Manuel on Wed Jun 24, 2020 11:17 pm, edited 3 times in total.

Carsten
Posts: 1596
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Potential DCP issues (file system, audio channel order)

Post by Carsten »

We had easyDCP player warnings earlier as well. Unfortunately, you only get explanations for these warnings with the full version. Bit of a neat trick...

Usually, these are just minor formal complaints. DCP is quite complex, and some formal aspects can be argued about, without them being an actual problem. You can try to verify the DCP with DCP-o-matic players verify function to make sure it is hashed correctly, but, I wouldn't be concerned just because of easyDCP.

- Carsten

Manuel
Posts: 2
Joined: Wed Jun 24, 2020 4:30 pm

Re: Potential DCP issues (file system, audio channel order)

Post by Manuel »

Gotcha. Yes, easydcp player's hash check itself verifies everything fine. It is a neat trick ;)
Fingers crossed, then!

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