Carsten Kurz: Tiny note there: There are Interop and SMPTE KDMs. Interop KDM is deprecated. While you could find systems which expect Interop KDM if you look very hard you need to generate SMPTE KDM for both Interop and SMPTE DCPs. Wolfgang

So are you saying SMTP is normally OK but occasionally I may need to generate a DCP if someone has a old server (although I guess they would want ot upgrade as they will not be able to play new commercial DCPs). Ben On 2 August 2014 09:08, Wolfgang Woehl &lt;tito(a)online.de&gt; wrote: -- *Ben Edwards, Video Editor and Cameraman* *web*:*www.nkytwig.com* <http://funkytwig.com/>* mobile:**07773 02 44 82* *skype**:**funkytwig** twitter:**@funkytwig* <https://twitter.com/funkytwig>iContact Community Video <http://www.icontactvideo.org/> | Bristol Community Channel <http://bristol.mirocommunity.org/>

Am 07.08.2014 um 19:49 schrieb Ben Edwards: It's a bit more complicated than that - current commercial DCPs basically are all Interop, but KDM, the KeyDeliveryMessage for encrypted content ran through it's own format changes over the years. Wolfgang is right that 'classic' Interop KDMs are outdated now, whereas the 'Modified Transitional 1' is, as the name says, a breed between Interop and SMPTE and aimed towards compatibility with both Interop AND SMPTE DCPs. DCP-o-matic supports no 'old style' Interop KDMs, but it does support Interop DCPs - and if encrypted, they currently should be be used with the 'Modified Transitional 1' KDM type. This is all about playing safe - the specific projection system you are testing it on may be ok with either version, but any other system may not. So stay with these recommendations. - Carsten

On Thu, 7 Aug 2014, Ben Edwards wrote: As far as I can tell, the normal approach here is to send the distribution company the (encrypted) DCP. They will give you a certificate for their system, and you make a KDM for this certificate. That KDM gives them the secret keys that encrypted the DCP so that they can make new KDMs themselves to send to cinemas. You could send them just the raw key (as is held in the metadata.xml) but this is unsafe as if it were to be intercepted then the interceptor could decrypt your DCP. Carl

Am 02.08.2014 um 12:33 schrieb Ben Edwards: Your content WILL be converted to 4:4:4/12Bit anyway, as this is the only format supported in a DCP now. The question is, should this happen in Premiere, or in DCP-o-matic/FFMPEG? You probably know that the fourth '4' in 4444 effectively is not used here, as alpha channels have little use in final compositions. If you have access to a high quality screening system, it would be interesting to test both variants. I won't challenge Carl on this, but I would at least assume that Premiere does a better job directly from the timeline - because the up-conversion/requantisation takes place before the ProRes compression. I would again assume that in DCP-o-matic then, only Prores decode and color conversion takes place prior to J2K compression. There would even be a better workflow in creating the xyz J2K directly from within Premiere, as it leaves out the intermediate Prores compression. That said - there can be differences between theory and practice when converting between different codecs, because some of their internal dealing with scaling, subsampling, gamma handling, colour conversion etc. is obscure. Then finally, even things done technically wrong or less optimal can still look better on screen ;-) So, nothing goes over visual testing. That's right, however, currently it is quite complicated to pirate an unencrypted DCP. At least it goes beyond the knowledge of most projectionists. There are no simple tools available to do that. If you don't put your DCP on the internet, the risk is fairly low. Some cinemas just keep unencryped content on site in order to play it occasinally for internal use, but they usually won't make business with it. The important thing to notice with encrypted DCPs and KDMs is that there is no universal key that works for all cinemas. A KDM is only valid for a single specific machine. KDM service companies/distributors maintain huge databases of cinema locations with all their certificates in order to be able to issue KDMs reliably in daily operations. This database is the core of their operations. So you need to reason if you want to take up that part yourself. Usually no problem for a specific screening, but in the long run it could become an issue to generate and maintain your own database. Yes, the Make KDM Dialog will allow you to setup a database of cinemas and screens, attach their certificates, and then select one of them for KDM creation. Actually the cinema environment is the only one with an internationally agreed perceptive loudness standard. There is still some variance in it, and I guess this will never be solved completely (one major issue is different expectations for entertaining loudness between 'typical' younger and older audience), but in general it works well. The formal reference setting at all cinemas is 'Fader level 7'. Actually most cinemas I know play preshow at 4.5-5.5 and main features at 5-6, though. If you do a screening at a cinema, check the processor setting yourself in the booth or on the wall control (if there is one). In my opinion, you should aim for your preferred loudness being reached at 5.5 to 6. This could become a long discussion, but in general, the reference level in nearly all digital cinemas should be the same, but the way projectionists, ushers, equipment, control, etc. are able to do adjustments on content with non-standard levels is different. In some locations, staff just dials in something on the wall control, then forget it for the next week. In other cinemas, levels are set automatically from the server per feature. There is one automation system I know of that actually takes the number of sold tickets for a specific auditorium and adjusts volume +/- to compensate for more or less crowded auditoriums. Commercial DCPs sometimes come with notes suggesting preferred fader settings to make sure the content is played back at the directors preferred level. E.g. 'Gravity' came with suggestions to play at level 7.2 (! the .2 is hilarious). And I just have an accompanying letter for a DCP between my fingers which says: 'Do not play this movie louder than 5.5' ;-) And that is NOT an action movie, but an arthouse flic. Looking forward to check it. These numbers may not tell you much, but the difference between 5.5 and 7.2 on the same feature is typically between 'just right' and 'deafening'. I notice that 'highend' productions typically can be played more towards the 7 - e.g. we played 'Gravity' and 'Lincoln' at 6.5 without any complaints, and I guess 7 would have been still ok, at least in a full auditorium. - Carsten

Hi all, One thing that is also useful is to measure the loudness of the source material (according to the EBU R128 specification). Unfortunately there is no standard loudness value in LUFS defined for cinema[1] as there is for TV broadcast. According to my investigations of about 100 professionally mastered DCP:s distributed in the wild the average lies somewhere around -24 LUFS. You can use the ebu128 filter in ffmpeg to check the loudness of a video or audio file: cat <videofile> | ffmpeg -i - -filter_complex ebur128=peak=true -f null - To check on a DCP with audio mxfs split into reels, you could use shell wild cards, e.g.: cat Naganting_maste_ga_sonder_FTR_F_SV-EN_51_SV_2k_20140121_FT_audio_0* | ffmpeg -i - -filter_complex ebur128=peak=true -f null - The nice thing about the "Integrated loudness" (I) is that it changes along with the audio gain. E.g. If you have material with an integrated loudness of -16 LUFS (too loud), change the gain -8 dB to get -24 LUFS. 1. Discussed extensively here: http://www.gearslutz.com/board/post-production-forum/768373-cinema-playback… Best, -mattias

Am 02.08.2014 um 21:26 schrieb Ben Edwards: There is no easy solution to that. If you mix in 5.1, you need a decent 5.1 system for monitoring. Professional film mixing stages use similar equipment as in real cinemas, and they are calibrated with the same mechanism, that means, they also use a cinema processor at fader setting 7 to create the 85db SPL for the calibration. That's the idea of the Dolby level 7 in cinemas - mixing stages and cinemas adhere to the same reference level. In theory, you could do that calibration on your own monitoring setup, but it's hard to keep a level/setup discipline on non-pro audio gear, computer soundcards, etc. The good thing is that you are working in an absolute digital audio reference system - the same 24bits that your computer delivers to your audio card can be transferred 1:1 to a digital cinema system. That was more complicated in the analog film days where a lot of analog reference levels had to be maintained throughout the monitoring and master transfer chain, not to speak of the complex behavior of analog matrix sound systems. Mattias suggestion to use the EBU128 filter for an analysis is not bad. Common VU type readings are useless, as they do not weigh perceptual aspects of the sound. Peak levels are irrelevant, unless they indicate clipping. For a monitoring setup, I think it is best to avoid as many analog stages between your computer and speakers as possible. I think the easiest non-pro setup would be to feed up to 8 LPCM channels from a graphics card HDMI/Black Magic Design HDMI output directly into a Home AV receiver. After proper setup, there should be only the AV receivers master volume control that can mess up your reference level. Mark it, and you should have some piece of mind. A lot of semi and pro audio cards have AES/EBU outputs, but I rarely see 5.1 or 7.1 receivers with discrete multichannel capable AES/EBU inputs, at least not in the price range I could afford. For people with less ambition to spend extra money on a monitoring system, I actually suggest getting a range of common DCP trailers from a projectionist, e.g. different programm types like dialog, action, music, etc., extract the audio (which is possible as these trailers are unencrypted), and play it on your monitoring system as a reference to your own material. If reliable monitoring to spec'd levels would be easy, we wouldn't have this discussion. ;-) - Carsten

Am 02.08.2014 um 18:04 schrieb Wolfgang Woehl: I just recently came across these ISDCF meeting materials with some interesting aspects covered: http://www.isdcf.com/meeting/Loudness%20Issues%20In%20Cinema%20–%20EU%20-%2… http://www.isdcf.com/meeting/Levels%20in%20the%20Theatre.pdf Adding to my remarks - to be precise, only Level 7 is more or less guaranteed to yield a specific loudness, because that is the fader setting which is (should be) used for the calibration process. While all cinema audio processors use this 1 to 10 scheme, a level 5 on a USL or Datasat processor could/will be different from a level 5 on a Dolby processor. Though I assume that these manufacturers all try to simulate the same gain/fader relation as Dolby does. DCP-o-matic still has a hidden preference option for different level/gain relations of different processors, but I think currently only the Dolby system is used. I think the origin of the Dolby Level numbers is a control voltage steering a VCA block in Dolbys earlier analog processors. I think that they were off at 0 volt and full on at 10 volts. That was a common system for VCA circuits, also in analog music synthesizers of the time. Dolbys later digital systems then tried to simulate the same behaviour, as other manufacturers. Sometimes I come across forum statements from people claiming to play main features mostly at 4-5. Something must be wrong there. - Carsten

Mike, if you read my previous post, you will notice that I do not advocate playing at 7 blindly. As a matter of fact, we have never played a single feature at 7. Not even when I do personal qc on a new feature do I choose to play at 7, even as a sound pro it isn't fun for me at these levels. Also, I have no idea wether the fader level/attentuation relation is the same between your CP650 and our AP20. So, it may be that your 4.8 is essentially the same as our 5.5. Your mentioning of playing Gravity at 6.5 may suggest that we have identical calibration levels at level 7 (what should indeed be the case for all cinemas), but not even that is sure. But I know for sure that 'no complaints about sound being too soft' is no evidence that a cinema is doing it 'right'. An all time 'no complaint level' will typically result in a sound level that will leave most of the audience untouched by the sound. Intense dialog perception needs the subtleness of the human voice to come through, as well as spontaneous excitement. If you're checking individual features for a proper dialog level, that is probably the best thing to do. Although I usually then still choose to give it a bit of boost from there, because the level needs to be higher for populated auditoriums, and the adjustment range between 'just right' and 'too loud' in my opinion should be used towards the top, not the bottom, for the reason I explained above. This, of course doesn't mean using 7 instead of 5.5, but e.g. choosing 5.8 to 6 if 5.5 seems to be 'just okay'. You are, of course, as every cinema operator, the one who knows your audience and sound system best. Even with the best calibration, a single number can never cover all aspects of a specific cinema sound system coupled with an audiences expectations and habits. I just want to make clear that, from a 'cinematic experience point of hearing', 'too soft' is equally bad as 'too loud', even if it doesn't trigger complaints. - Carsten Am 03.08.2014 um 09:05 schrieb Mike Blakesley / Roxy Theatre / Valley Auto: