DCP BEST PRACTICES 2018 - INTERNATIONALE FILMFESTSPIELE BERLIN - Berlinale
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INTERNATIONALE FILMFESTSPIELE BERLIN
DCP BEST PRACTICES 201868. Internationale Filmfestspiele Berlin
DCP Best Practices 2018
Content
Introduction ................................................................................ 3
Best practices in an nutshell ............................................................ 3
General ...................................................................................... 4
DCP concepts............................................................................... 5
Structure.................................................................................... 5
Files ......................................................................................... 5
XML Files ................................................................................ 6
MXF Files ................................................................................ 6
Encryption / KDMs ......................................................................... 6
Version Files / Supplemental DCPs ..................................................... 6
Subtitles .................................................................................... 7
Naming ...................................................................................... 7
Image Format .............................................................................. 8
Audio Format............................................................................... 9
Delivery of DCPs ........................................................................... 9
hard drives ................................................................................. 9
Delivery by network ....................................................................... 9
Frequently Asked Questions ........................................................... 10
Page 2 of 1168. Internationale Filmfestspiele Berlin
DCP Best Practices 2018 Introduction
INTRODUCTION
The purpose of this document is to provide basic information on DCP Concepts, DCP Mastering and DCP
Distribution to productions with no to limited previous DCP experience including information on how
to best prepare and supply a DCP to the festival.
BEST PRACTICES IN AN NUTSHELL
- Always use the naming convention (v 9.3) see: http://isdcf.com/dcnc/
- Clearly label all discs, specify which CPLs to use and provide technical contact information
- Respect the deadlines
- Do not use 2.5’’ HDDs or USB sticks – use CRU if possible
- Complete proper tests / QC of all DCPs in a DCI compliant screening facility in advance
- Format disk drives in ext2/ext3 and use MBR – do not use GPT
- When delivering VFs please supply the required OV
- Provide “Modified Transitional 1” DKDMs
- Do not send DKDMs by e-mail, instead upload through the festivals KDM portal
- DKDMs need to be valid from the day the DCP arrives until the end of the festival
- If possible use burned-in subtitles instead of XML / PNG
- Contact the festival for HFR, 3D, Atmos & Auro DCPs to check for venue compatibility
- If possible do not send DCPs with stereo audio (2.0)
- Do not send DCPs using Full Container
- Do not create nested DCPs – no DCPs inside DCP directories
Page 3 of 1168. Internationale Filmfestspiele Berlin DCP Best Practices 2018 General GENERAL DCP (Digital Cinema Package) is the standard delivery format for digital cinema projections – or simply put it is the equivalent of a 35mm film print in the digital era. To create a DCP from existing media (tapes, discs, files) a mastering system or software is needed to encode the data in the correct format, add encryption if needed and combine all data in a package. We recommend having the DCP mastered at a professional post-production facility since the color-space conversion requires in-depth experience. If you decide to create the DCP yourself using commercial or open-source software we ask you to test the DCP in a DCI-compliant cinema to make sure it is playable and your color-space conversion was correct. Please do not send untested DCPs to the festival. The Film Office of the festival will run a number of tests to make sure all DCP comply with the standards and are operable on all systems throughout the festival. In 2018 the festival and the EFM will only use Dolby, Barco and Sony servers for the playback. Depending on the data-rate a DCP uses about 1,5 GB to 2 GB of hard-disk space per minute – therefore it is important to use hard-disks that allow for a fast transfer onto the festivals storage servers. Page 4 of 11
68. Internationale Filmfestspiele Berlin DCP Best Practices 2018 DCP concepts DCP CONCEPTS STRUCTURE The VOLINDEX has to be present in any DCP and is used in case the data of a DCP needs to be spread over several devices or hard drives. With the size of hard disk available today it is common practice to store the whole package on one device. The PKL or PackageList and the Assetmap contain a list of all files required to play package and additional meta-data to organize the files within the DCP. The CPL or CompositionPlayList defines how the movie should be played, by defining which assets should be included in the picture, sound and subtitle tracks. It can be compared to a timeline in an editing application. Just as a traditional 35mm print a CPL can include several reels, each using different assets. One PKL or package can contain several CPLs with different versions of usually the same movie. These versions can for example differ in language, subtitles, length or audio language. By defining the start or entry points for the different assets CPLs allows for simple “editing” like skipping a leader in a certain version. FILES The DCP is made up of several files that contain the picture, sound, subtitle and meta-data. These MXF and XML files usually reside in a folder labeled with the title of the DCP – for details on correct naming please see the section on naming below. In case your DCP uses subtitles there might be several additional folders containing subtitle information. It is essential that no files are changed or renamed after mastering the DCP or otherwise the DCP can no longer be operative. Page 5 of 11
68. Internationale Filmfestspiele Berlin DCP Best Practices 2018 DCP concepts XML FILES XML (Extensible Markup Language) contain a defined set of hierarchically organized elements that can contain various data. In DCPs the XML files are used to set the structure of the package and to hold meta-data like naming or encryption information. MXF FILES The general concept of MXF (Material eXchange Format) files is to function as a file wrapper for one or several files along with storing meta-data information. MXF picture files contain a sequence of compressed, encoded and optionally encrypted JPEG2000 images whereas the MXF audio files contain several linear mono PCM audio tracks. The optional encryption standard is AES 128 bit in CBC mode. It is important to note, that in DCPs JPEG2000 files use the XYZ color space instead of RGB or REC.709 commonly used in digital video. Therefore images have to be converted into the XYZ color space during encoding. ENCRYPTION / KDMS The DCP standard allows content to optionally be encrypted to prevent unauthorized screenings. This is accomplished by encrypting the picture and/or audio MXF files within the DCP. To enable playback a small XML file called KDM (KeyDeliveryMessage) is needed, it contains the necessary keys for decryption. The KDM is specifically targeted to a certain screen (playback device) and is valid only within a set timeframe. By providing a DKDM (Distribution KDM) the festival can be authorized to generate KDMs for the screenings as needed. This allows for last minute changes and eliminates the need for a large number of individual KDMs. It is important to note that KDMs are not issued per DCP but for each CPL of the DCP individually. By issuing only one DKDM you can make sure that the correct version of the movie will be played. VERSION FILES / SUPPLEMENTAL DCPS Version files also know as VF or supplemental DCPs are usually used to create a subtitled version of an original DCP (called OV for original version). These version files do not contain the assets (picture and sound files) of the OV but only the additional subtitle information. Therefore it is essential to provide a matching OV along with any VF since the VF relies on assets only available in the OV. If you plan to submit a version file to the festival we kindly ask you to send OV and VF together in one clearly labeled shipment however OV and VF can be delivered on two separate hard drives. Page 6 of 11
68. Internationale Filmfestspiele Berlin DCP Best Practices 2018 DCP concepts SUBTITLES As stated above a CPL can contain a separate subtitle track for each reel. These subtitles can either be text-based (XML) or be images based (PNG). If used in a version file it allows for easy addition of subtitles to an existing DCP without the need of re-encoding the images, however we strongly suggest that you create a new DCP with subtitles burned into the image. When using burned-in subtitles please make sure that all text is positioned within the title safe area (5%). Our experience has shown that the most issues encountered during playback are due to errors in the subtitle tracks. NAMING The film title along with technical information should be placed in the ContentTitleText element of the CPL (CompositionPlayList). The naming should comply with version nine of the Digital Cinema Naming Convention that can be found at: http://isdcf.com/dcnc/ The below diagram gives an overview about the types of information that have to be included in the ContentTitleText. Please closely follow this guide, especially if you are new to DCP mastering. Page 7 of 11
68. Internationale Filmfestspiele Berlin
DCP Best Practices 2018 Image Format
IMAGE FORMAT
The DCP format only specifies three different aspect ratios for the image:
Flat Format aspect 1.85:1 (1998x1080 or 3996×2160)
Scope Format aspect 2.39:1 (2048×858 or 4096×1716)
Full Format aspect 1.9:1 (2048×1080 or 4096×2160) – NOT RECOMMENDED
Although not specifically defined most playback devices will also support:
HDTV Format aspect 1.77:1 (1920×1080 or 3840×2160) – ONLY RECOMMENDED FOR 1.77
Since some venues do not support Full Format and the aspect 1.9:1 is not commonly used in cinema,
we do not recommend that you master your movie in this format. Using this format might result in
cropping of the image during presentation.
Please see the table below for recommendations on formats to use:
Screen Aspect Flat Format Scope Format Full Format HDTV Format
1.33 : 1
pillarboxed
1.37 : 1
pillarboxed
1.66 : 1
pillarboxed
1.77 : 1
pillarboxed
1.85 : 1
2.39 : 1
2.55 : 1
letterboxed
Page 8 of 1168. Internationale Filmfestspiele Berlin DCP Best Practices 2018 Audio Format AUDIO FORMAT All our venues are equipped with 5.1 or 7.1 audio systems – some also support the immersive audio systems Dolby Atmos or Barco Auro. Although it is possible to create a stereo audio DCP not all cinemas are able to upmix the stereo sound. The result can be a mute center speaker during presentation which should be avoided. We therefore ask for 5.1 DCPs to have a minimum of three active channels (Left, Center, Right) with the remaining three channels muted. DELIVERY OF DCPS HARD DRIVES We generally prefer to receive hard drives in the industry standard CRU DX115 frame. These are designed specifically for digital cinema and allow for a fast copy process of the DCP onto cinema servers or in our case onto our central storage system. If you cannot send a CRU frame you may also submit a USB drive. When sending DCPs on physical hard-drives, we generally prefer external 3.5” USB or eSATA hard drives with 220V compatible power supply. If it is impossible for you to provide a 3.5” USB or eSATA hard drive we can make an exception and accept 2.5” hard drives or USB sticks. Hard disks need to be Linux formatted in EXT2 / EXT3 to be playable on all systems and they need to use Master Boot Record (MBR). The inode-size should be set to 128. On a Linux system you can use the command: sudo mkfs.ext2 -j -I 128 /dev/sdaXX “/dev/sdaXX” should be replaced with the device you want to use for the DCP. Do not use NTFS (Windows) or HFS+ (Mac) formatted drives for delivery to the festival. In case you plan to supply several DCPs (packages) on a single hard-drive, they should be placed into separate directories inside the root directory of your hard-drive. Although the standard only allows for one Assetmap per drive it is common practice to have one Assetmap per package or DCP-directory. Do not use DCP-directories inside DCP-directories. The drive should be well labeled with CPL and encryption information and be well packaged to prevent any damage during transport. DELIVERY BY NETWORK DCPs and Quicktime ProRes files can be digitally transferred to the Berlinale Film Office. We provide this service through Aspera. If you want to use the service you should contact a professional postproduction facility that offers one of these services or have a fiber internet connection with an upload bandwidth of at least 50 Mbit/s. For access and account information please contact films@berlinale.de. Please note that all DCPs have to be received on our servers before the deadline. Page 9 of 11
68. Internationale Filmfestspiele Berlin DCP Best Practices 2018 Frequently Asked Questions FREQUENTLY ASKED QUESTIONS What is a DCP? DCP is an acronym for Digital Cinema. One such package can contain multiple versions of one film and even multiple films. Different versions or playlists are called CPL (composition playlist). What is a KDM? KDM is an acronym for Key Delivery Message and is simply put the file-based key needed to unlock an encrypted CPL within a DCP to be played at on a specific playback device during a certain timeframe. What is a certificate? A certificate or public-key is the file-based information about a playback device needed to issue a key or KDM for this specific device. In our case Berlinale will supply you with a certificate from our key- management system. You will be asked to supply a single KDM for this system. Berlinale will then be able to generate KDMs for use at the festival as needed. Should we prepare a DCP for our Berlinale screenings? During the last couple of years cinema operations quickly adopted the Digital Cinema system proposed by the DCI and all Berlinale screens are now equipped with digital projection systems. However, if you do not wish to supply a DCP you can also supply Quick-Time ProRes files or tape-based media like HDcam. In that case we will create a DCP solely for use at the festival. Can I get a copy of the DCP that Berlinale creates from my QuickTime / tape? No. All DCPs created by the festival are encrypted and we will not be able to give you a copy of the DCP or of the keys that we use. Should be prepare an Interop or an SMPTE DCP? Currently all systems used by the festival and the EFM are capable of playing both Interop and SMPTE DCPs. We highly recommend that you prepare a SMPTE DCP as is has various advantages over the older Interop format, specifically they provide a wider range of frame rates, metadata, improved security, more robust subtitles. Who should create my DCP and how? Preparing a DCP requires in depth knowledge of digital video, audio formats and digital color spaces. It is recommended that DCPs are being mastered at professional labs or postproduction facilities, however more and more software products are on the market that can be used to create DCPs on desktop computers. When using those products special care should be taken in labeling (naming convention), color-space conversion and media-/screen-format. In any case a QC (test-screening) in a SMPTE compliant theatre should be completed before sending the DCP to the Berlinale. Why and how is Berlinale testing my DCP? Our experience has shown that quite a number of DCPs delivered to the festival have technical errors and would cause issues during the presentation. As a precaution we have developed a highly automated testing routine that all DCPs go through. It is still your responsibility to properly test the Page 10 of 11
68. Internationale Filmfestspiele Berlin DCP Best Practices 2018 Frequently Asked Questions DCP in a SMPTE compliant digital cinema beginning to end before sending it to the festival. Our tests then focus on data-structure errors and interoperability issues that might arise during playback on a specific projection system. Can I be present while you test my DCP? No, due to security reasons we do not allow any visitors in our internal QC process. Can I schedule a test-screening or rehearsal for my DCP screening? Due to the tight schedule of the festival and the EFM we generally do not offer test-screenings for DCPs. Your DCP has to be tested before it is submitted. The only exception to this rule applies to films in the official competition and to EFM customers that have booked an additional test-screening. What if Berlinale encounters problems with my DCP? If we should find problems with your DCP during our QC/IC process we will contact you with a detailed error report and work with you to resolve the problem. Normally we will ask you to supply a corrected version of your DCP. In special cases we can try to fix the problem if you provide written permission to do so and if you give permission through the KDM upload portal. Why does Berlinale need a DKDM (master key) for my screenings? There are two reasons why we ask you to supply us with a DKDM: 1) A DKDM lets us generate KDMs (key) for the theatres that we use during on a very short-term notice. In case we need to reschedule a screening or swap projectors / servers we are able to generate new keys as needed. 2) It enables us to test your DCP in our secure environment in advance. Without a key we cannot perform a number of critical tests. How does the festival store my DCP and KDM? Both DCPs and KDMs are stored in a secure environment. Special access-control applies to the DCP storage room, ingest-systems and the data-center where all data is centrally stored. Why are the colors strange when I look at the JPEG2000 files in my DCP? If you open the MainPicture Asset of your DCP in an application like VLC you will see a RGB representation of your images in XYZ color space or in other words you are looking at your image on a display that cannot correctly display it. The only correct way to look at your files would be to use a YZX capable playback device like a DCI compliant projector. I found that the colors/contrast during my Berlinale screening did not look right. Can you adjust the projector for my repetition screenings? No, we will not be able to change any color/contrast/brightness settings in the projector. The idea of the digital cinema system is to have a defined gamma, colorspace and brightness. All our venues are calibrated to DCI / SMPTE specifications before the festival and are verified throughout the festival. Page 11 of 11
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