Film-Tech Forum ARCHIVE: KDM compatibility problems with Dolby System 4.4?

This is topic KDM compatibility problems with Dolby System 4.4? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Antti Nayha (Member # 4980) on 07-20-2012, 01:57 PM:

I'll be managing the projection side of things for a large-ish film festival that starts in four weeks now. Our digital booths will all use Series 2 projectors and Dolby DSS200 servers, which is a very nice thing in a festival setting - compared to having to deal with a mixture of old and new equipment and their unique quirks.

However, it looks like at least one of our Dolbys will be running DCI-compliant 4.4 software, while the rest will still be at 4.3. So far, I’ve only ever worked with Dolby software up to version 4.3, and I've been advised by several people (including some on this forum) not to update to 4.4 before it’s absolutely necessary.

Now, I've heard reports about cases where some KDM's have been incompatible with 4.4. I've understood that those problematic KDM's have been mostly (exclusively?) created by "indie" type mastering facilities - on the other hand, KDM's supplied by one of the big labs have generally worked flawlessly on both 4.3 and 4.4. Of course, festivals tend to receive a lot of stuff from the indie companies, and some of the material can be... well, mastered in an interesting fashion, as discussed in the "film-less film festival" thread earlier.

Looking for information about the KDM problems, I found this bit in 4.4.0's release notes:

quote:
Composition Playlist Validation Checking
The system enforces composition playlist (CPL) validation checking per DCI requirements unless the associated content has a Modified Transitional 1 KDM, as defined by the Inter-Society Digital Cinema Forum (ISDCF). Modified Transitional 1 KDMs do not contain the ContentAuthenticator element. To allow playback of Interop content, the system must have a Modified Transitional 1 KDM, as Interop content is not DCI compliant. Because all content is currently in Interop format, you should replace any KDM that contains a ContentAuthenticator with a Modified Transitional 1 KDM.

...but I’m not sure if this is related to the problems mentioned above at all. I don’t think I’ve ever even come across a ContentAuthenticator element in a KDM.

Does anyone happen to have any dirty details to share about such problem cases with 4.4? I'm just wondering if there's anything I can do to prepare for such events (barring early ingestion and testing, of course). Naturally, I can check all KDM's looking for ContentAuthenticator elements - but what else?

While I'm here: any other useful tips for a 4.4 virgin? Thanks in advance!

Posted by Kris Verhanneman (Member # 5562) on 07-21-2012, 04:49 AM:

there is only 1 thing that I heard on the version 4.4

- Make sure that the server and projector certificates/serials are know to the distributeurs.

In version 4.4 both server and projector can be in the KDM files.

That is the only issue I heard on dolby 4.4 and serie II projectors.
Personaly: we are still on 4.3.9 and it runs nice. Would like to keep it but I guess the 4.4 will arrive in september.

Posted by Steve Guttag (Member # 268) on 07-21-2012, 03:42 PM:

So far, all of our 4.3 to 4.4 transitions have been smooth. No KDM issues and I have not heard anything about the projector being in on the KDM thing. TLS encryption is now the only Cinelink 2 option but that is pretty old news since all series 2 projectors require that too.

I have had once instance of no picture but with sound and I have heard of others that have experienced it. The percentage of failure though is in the small fractions less than 1%.

I have done both remote updates as well as with a disc...all were problem free.

Posted by Wolfgang Woehl (Member # 6901) on 07-23-2012, 01:45 PM:

A KDM with ContentAuthenticator is perfectly alright when it references a signed SMPTE CPL which is in turn part of a SMPTE 429-2 compliant DCP. We'll see more and more of these while the transition from Interop DCP to the latter is ongoing.

So Antti, when checking KDMs you can't entirely dismiss KDMs with ContentAuthenticator unless you're checking the referenced composition (and package) as well.

Plus what Kris said about projector certificates. These will increasingly show up in DCI specific KDMs (AuthorizedDeviceInfo > DeviceList) and DCI-compliant systems will start to require them in KDMs.

Posted by Antti Nayha (Member # 4980) on 07-24-2012, 10:28 AM:

First, thanks for all the replies.

quote: Wolfgang Woehl
A KDM with ContentAuthenticator is perfectly alright when it references a signed SMPTE CPL which is in turn part of a SMPTE 429-2 compliant DCP.

Yeah, I got that part, so I'm planning to check the DCP's with dcp_inspect as well to find out which ones are SMPTE. Thanks for writing that software, by the way! [Cool]

I'm currently trying it out, and will write some feedback a bit later in the Digital Cinema Tools thread.

Posted by Dave Macaulay (Member # 813) on 07-24-2012, 10:40 AM:

Realistically SMPTE DCPs are pretty rare now (but coming!). I don't think this one is a projector certificate error. I haven't seen any content with this "trusted device" (meaning "untrusted exhibitors", of course) stuff enabled.
The DCI compliant software does much more rigorous checks of signatures etc. for all DCP and KDM elements, as I understand it. If a content creator has consistently had an error in the DCP or KDM, previous versions didn't check everything and would accept them without comment. I've had this happen with a non-major distributor - encrypted content A-OK with old software, failed security validation with new software. Fixing the problem was easy, I sent them a picture of the server error message and the issue was soon resolved.

Posted by Olivier Lemaire (Member # 5579) on 07-24-2012, 10:44 AM:

I already did see "untrusted devices" with KDM, when on a dual projector setting - but it was not with a Dolby media block, but a Doremi one.
(Solved by the way issuing a correct KDM, indicating projector's certificates - as required in a dual projection system).

Posted by Antti Nayha (Member # 4980) on 07-25-2012, 03:37 AM:

quote: Dave Macaulay
The DCI compliant software does much more rigorous checks of signatures etc. for all DCP and KDM elements, as I understand it. If a content creator has consistently had an error in the DCP or KDM, previous versions didn't check everything and would accept them without comment.

Now, this is starting to sound like the problem I was referring to in my first post! So I guess there's no way to recognize such problem cases before ingesting... but I will try and test all non-major-lab-originated content first.

So far I've encountered just a few SMPTE DCP's, and those were all unencrypted so no KDM problems there. All but one were European short films, shot at 25 fps and distributed as an SMPTE DCP at the original frame rate (since 25 fps Interop doesn't exist as far as I know). I've only even seen one (short) film distributed as 24 fps SMPTE.

Posted by Antti Nayha (Member # 4980) on 08-29-2012, 04:38 AM:

Just wrapped up the festival. There were a total of 47 DCP screening copies, 16 of them KDM-free. All were 24 fps, all but one were Interop and none of the KDM's had a ContentAuthenticator element.

No problems whatsoever on either 4.3 or 4.4 Dolby software (many films were played on both). This year we didn't even have a single DCP subtitling problem! [Eek!]

Either we were very very lucky, or the world is slowly turning into a better place.

Edit: actually we did have minor playing-when-ingesting hiccups on a DSS200 (4.4 software, four 1 TB drives, all freshly formatted). The playback just froze for a second or so a few times. I haven't seen this in a while, and never really had time to pinpoint the problem. Stopping the ingestion solved it immediately, and for the rest of the festival we just did all ingestion overnight at that venue.