Film-Tech Forum ARCHIVE: Can I have two overlapping keys for the same movie?

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Posted by Frank Cox (Member # 6258) on 06-20-2018, 10:54 AM:

For some strange reason the key that I have for my next movie (Book Club) expires at 3am next Wednesday. Which means that it's not valid for the Wednesday and Thursday shows.

Thinking that this was an oversight by Deluxe I sent them an email expecting a key that covered the entire week, and got this reply instead:

quote:
You will receive the keys for 06/26 00:01 - 06/29 03:59 closer to the start date.

So that apparently means that I'll have two keys for the same movie.

My question is, can I load them both on my server at the same time and expect everything to just work through the entirety of my run, or should I wait until next Wednesday after the first key expires to load the second key for Wednesday and Thursday night?

Posted by Mike Blakesley (Member # 26) on 06-20-2018, 11:55 AM:

Yes, I've seen this once or twice. Sometimes we've received two keys for the same movie, both active through the whole play time. Bottom line, the server doesn't care how many keys are valid at the same time.

Posted by Jim Cassedy (Member # 4115) on 06-20-2018, 02:10 PM:

99.9% of the time it shouldn't be a problem.

I've had several situations where I had 3 back-to-back press
screenings of the same film, for different groups of people,
on the same day, and instead of the studio sending me one
key for the entire afternoon, they sent 3 keys with slightly
overlapping times. On a couple of occasions, the server
(DSS-200)gagged on this and wouldn't play one of the
shows, and I understand this happened to one of the
otherprojectionists who work that room too.

Rebooting solves the problem.

So now, when we wind up in that "multi-key" situation, we
just wait to ingest each key separately right before each
show since there's usually at least 30min between screenings
and since we run everything manually there's always somebody
in the booth at all times anyway, so they might as well be
doing something.

But I'm in a unique situation. Most of the time, having
overlapping keys, shouldn't be a problem.

Posted by Marcel Birgelen (Member # 6801) on 06-20-2018, 02:40 PM:

I believe that multiple, overlapping keys is a mandatory feature of DCI certification and most of the times it will just work.

Maybe you can tell us what server you have and if it worked as anticipated.

Posted by Carsten Kurz (Member # 5396) on 06-20-2018, 04:15 PM:

There is a passage in the standards that deals with this, and, there are two different ways how to deal with this - one implies the option to revoke an initial key, meaning that any key issued later should supersede the one being issued earlier. This, however, could introduce problems with the common habit of prolongation KDMs, so, typically, successive KDMs are issued with overlapping time windows. I think there is a rule that says, if a feature has never been played using the first KDM, then upon receiving the second KDM, the first KDM should be invalidated. If the feature has been played once, the first KDM should remain valid. Again, the idea is that KDMs could be revoked by a second one with a different time frame.. It's weak, though, since the operator usually devides to ingest KDMs and when. Also, some systems allow to delete individual KDMs anyway.

Our Sony lists multiple KDMs as attached to a feature even when they are ingested at the same time, and simply adds up the time frames contained in them, so, no issue.

- Carsten

Posted by Leo Enticknap (Member # 534) on 06-20-2018, 08:57 PM:

I've had consistent problems with the Dolby cat745 and this. When two KDMs are ingested with overlapping open periods, if you try to select the CPL for playback during the period when both KDMs are open, it will give you the yellow "Checking content and licenses..." for about 30 seconds, and then revert to the white "Please select a show for playback." I have seen this happen (both to me and others I've helped on service calls) on software versions from 4.6.something through to 4.9.0. If this happens, the only fix I know of that works is to delete all the KDMs from the IMB and the affected CPL from the server, reingest the CPL, and then reingest one KDM only. Do not ingest the second KDM until the first has expired.

I've only experienced this problem with this specific model of IMB.

Posted by Frank Cox (Member # 6258) on 06-21-2018, 12:05 PM:

My server is a GDC SX-2001A with (as far as I know) the latest software.

However, based on what you fine folks have told me here, I think I'll take the cowardly way out and just have one (valid) key at a time on the server. Easier to do that than to jump through hoops to fix any problem that might or might not arise otherwise, unlikely as it may be.

Posted by Jim Cassedy (Member # 4115) on 06-21-2018, 01:35 PM:

quote: Leo Enticknap
"Checking content and licenses..." for about 30 seconds, and then
revert to the white "Please select a show for playback."

Yes, Leo, that's exactly what I was talking about when I said the server
would occasionally "gag" on overlapping keys. Although I seem to recall
that a simple re-boot cleared the problem for us.
(DSS-200 & Cat 745- -don't remember what software vers)

But we haven't had the problem since we started avoiding loading
overlapping keys. We started doing that at least two years ago, &
I know the server has had software upgrades done since then, so
it's possible it's no longer an "issue" for us.

Posted by Carsten Kurz (Member # 5396) on 06-21-2018, 02:26 PM:

The Dolby are especially nasty here since they only allow to delete all KDMs on the MediaBlock at once, while other servers allow to delete specific KDMs individually.

- Carsten