DCP Tips and Best Practices for your Digital Cinema Package

What A DCP Is: 
A DCP (Digital Cinema Package) is the standard file-based theatrical screening format that has almost entirely replaced film prints over the last 10 years. A DCP exists as a folder of data files instead of film reels, videotape, or disks. DCPs are made by converting your common master video/audio files into the DCP file based format.

DCP Frame Rates:

• DCPs are most commonly at 24 frames per second (fps) which covers source frame rates of both 23.976 and 24 fps without frame rate conversion.
• A 24 frame DCP is compatible at most DCP theaters and considered the most compatible frame rate.
• Some venues and festivals will still ONLY support 24 fps DCPs.
• If your project has a frame rate OTHER THAN 23.976 or 24, yours will have other considerations.
• Some theaters/festivals can also handle DCPs that are 25, 30 and other frame rates, but you need to be certain and verify with them that they support your frame rate.
• You can either make a DCP in one of the matching supported frame rates or a decide to frame convert to 24 if your venue only supports 24.
• If you have a 29.97/30 frame project it will look better as a 30 frame DCP, but you need to confirm the venue’s acceptance of a 30 frame DCPs. If the 30 frame DCPs are not supported by your venue, then a frame conversion to 24 will be the final option.
• For best screening results, a frame conversion from 29.97/30 to 24 should be avoided if at all possible by delivering 30 frame DCP if supported.
• Frame rate compatibility is entirely in the hands of what the venue or festival accepts.
• If a 25 frame project needs to be covered to 24, it can be done as a re-time which is cleaner than a frame conversion. The re-time method changes run-time and audio pitch needs correction is typical  this method, but the visual is cleaner compared to a frame conversion. Same is true for 24 to 25.

HD, 2K, UHD, or 4K?

• DCPs can only be made in either 2K or 4K.
• 2K refers to pixels that have common 2K widths such as 1998×1080 (flat) and 2048×858 (scope).
• 4K refers to pixels in common 4K widths such as 3996×2160 (flat) or 4096×1716. (scope).
• HD (High Definition) and 2K projects typically become 2K DCPs.
• UHD (Ultra High Definition) and 4K projects typically become 4K DCPs, or down-converted to 2K DCPs.
• HD refers to projects that are 1920 pixels wide by 1080 pixels tall.
• UHD refers to projects that are 3840 pixels wide by 2160 pixels tall.
• It really only makes sense to make a 4K DCP if you have a 4K or larger master. Up-converting to 4K from 2K or HD is probably not beneficial.
• Most providers charge more to make 4K, so if DCP creation cost is a major consideration, 2K is usually cheaper.
• Compatibility is also a consideration. A theater must be able to accept a 4K and play it on a 4K projector in order for a 4K to make any sense. Some theaters can open a 4K DCP, but still only project it in 2K. Some theaters can’t open or reliably play a 4K DCP, so you need to verify that.
• Larger than 4K masters files will need to be down-converted to 4K or 2K. There are no DCP options bigger than 4K.
• If cost and/or compatibility is not a concern then a 4K DCP is the right choice for 4K (or UHD) projects.

Aspect Ratios: Full, Flat, Scope, Or Other?

• Note: “Full Frame” is a term that means the picture fills the whole screen, without letter-boxing or pillar-boxing or squeezing, in its native pixel dimension. If a master file has letterbox or pillbox, it is not “Full Frame”
• Note:  “Aspect Ratio” is defined by the pixel dimension of the actual image, not including any letter-boxing or pillar-boxing. For example 1998 pixels wide divided by1080 pixels tall is 1.85. 1.85 is a standard aspect ratio and in DCP terms is called “Flat.”
• DCPs are either 2K or 4K and there are only three aspect ratios supported in Full Frame, so there are only six options total.
• Two of the six options are called “Full” (not to be confused with “Full Frame”). “Full” is currently out of favor as it is considered the IMAX format and therefore is discouraged or not accepted by many theaters, festivals or distributers. It is no longer recommended unless specifically for IMAX use.
• For the record though, “Full” which has a 2K size of 2048×1080 for 2K and 4096×2160. When the image is full frame the aspect ratio is about 1.90.
• If your master is genuinely a full frame “Full” 2048×1080 or 4096×2160. It can still be used if that’s all you have, it will be letterboxed into one of the other supported DCP types.
• Ruling out “Full” usually leaves only four DCP options. “Flat” or “Scope” in either 2K or 4K:
• Flat is 1998×1080 in 2K or 3996×2160 in 4K and has an aspect ratio of 1.85 Full Frame.
• Scope is 2048×858 in 2K and 4096×1716 in 4K and has an aspect ratio of 2.39 Full Frame. This size is also known as “Widescreen.”
• If you have the luxury of mastering your film to the PERFECT size for Full Frame DCPs, then master in one of the four here:
• 1998×1080 for Full Frame “1.85” 2K, 3996×2160 for “1.85” 4K (called Flat).
• Or… 2048×858 for Full Frame “2.39” 2K, 4096×1716 for 2.39 4K (called Scope).
• There are many reasons why the PERFECT export is not available. If not, there are still options.
• A common non-standard situation is the 16×9 or 1.78 aspect ratio (such as Full Frame HD or UHD). There is no 1.78 DCP option, so instead, it is customary to put 1.78 into a Flat (1.85) DCP without cropping. Then it is contained in the Flat DCP with a thin black left/right Pillarbox. The pillars are 34 pixels in 2K and 78 pixels in 4K.
• HD letterboxed to other aspect ratios are scaled to the best matching DCP container, the best available choice between full frame, letterbox or pillarbox.
• Similarly, files of any size that are any aspect ratio other than 1.85 or 2.39, will fit into a DCP with ether some letterboxing or pillarboxing, not cropping.
• If your project is not exactly the size of a scope or a flat, it will be contained in the closest of the two options and padded with letterbox or pillarbox to make up the difference.

Color Space and Gamma:
Your project is most likely in a YUV (REC 709) or RGB color space or one of those variants.
Your DCP will be in a DCP/projection specific color space known as XYZ. When viewed outside of a projection environment, without a color space conversion DCPs looks weird. Not to worry. Please simply deliver us your material in your native finished color space. Our workflow will recognize the metadata of your colorspace and we do the XYZ conversion as part of our process.
If you know any details about your color grading setup (such as gamma 2.2 or 2.4) please let us know and we’ll dial that into your DCP transfer. If you are unsure of your gamma we will set your source to 2.2 by default.

Your Project’s Current Frame Rate And Possible Conversion Scenarios:

• In most cases you simply provide your project to us in its finished produced frame rate:
• 23.98 fps projects, we re-time to 24fps during the DCP process, resulting in a 24fps DCP.
• 24 fps projects remain in 24fps and result in a 24fps DCP.
• 24 frame DCPs are considered universally supported at most every DCP theater.
• Other DCP frame rates are often supported, but support of other frame rates needs to be verified with individual theaters or festivals that they are going to. Frame rates such as 25 and 30 fps.
• 25 fps easily convert to a 25 fps DCP as the frame rates match.
• 29.97 fps projects are best made and screened as 30 fps DCPs. Check with theater/festival first
• 29.97fps projects that can only be screened at 24 fps compatible theaters need to be converted to  24fps. This scenario is not ideal due to frame blending and motion lag artifacting but can be done if you have no other option.
• We improve 29.97 conversions by doing them in 2 steps, first to 23.98fps and then re-timed to 24fps.
• In many 29.97fps to 23.98fps frame conversion cases we use Teranex hardware to convert as the first step to the DCP process.
• 29.97fps in SD will be Teranex up-converted to 23.98fps. Then re-timed to 24fps.
• 23.98fps in SD will be scaled up with software up-converted and then re-timed to 24fps.
• 25 fps projects can remain in 25fps and result in a 25fps DCP  if your venue will accept it. Or we can discuss conversion options. There is nuance to this process and decisions to be made, so please contact us to discuss if a 25-to-24
• Same discussion if a 24-to-25 conversion is needed

Sound:

• Ideally your DCP should have a 5.1 surround mix or a minimum LCR (Left, Center, Right) mix.
• You can supply the mix, either already attached to the picture media, or as separate audio files.
• If separate, we will be ideally looking for 6 separate mono WAV (OR AIF) files per channel, as 48K, 24 Bit (Left, Right, Center, Lfe, Left Surround, Right Surround).
• It is okay if the head and tail build of the audio and picture don’t match (for example, the audio has tones and the picture doesn’t or visa-versa). We will re-sync and trim accordingly.
• Please try to provide the sound mix in the frame rate of the picture master.
• For example if the picture is 23.98fps, then provide the sound in 23.98fps. 23.98fps projects will be conformed to 24fps in our DCP workflow. If you know the picture and sound are at mismatched frame rates, just let us know what you know so we have a heads up. We can usually adjust that on our end. If you don’t know or don’t tell us – don’t worry, we’ll figure it out and fix it along the way.

If your project was never mixed in 5.1 and you only have a stereo mix there are still several possible options:

• Speak with the person who mixed your sound originally and see if a 5.1 versioning is feasible.
• It is also possible to ask for an “L,C,R” (left, center, right), where dialogue plays mostly center and music and effects play mostly left and right. This helps the audio “image” to fill the screen where a stereo mix doesn’t as well. Some DCPs must have a minimum of a L,C,R. For example, some Academy Awards submissions have been known to require a minimum L,C,R.
• If working with us, it is possible for us to create a 5.1 “spread” from stereo mix split/stems as an optional service. In order to do this we need to get your stereo D/M/E stems. They are stems meaning that the split Dialogue and Music and Sound Effects are on three sets of stereo tracks in their mix relative levels. Meaning that if you play all three stereo stems together, the end result is the mix that you are used to and nothing different. In order for this to work, you would need to have created or already have stereo D/M/E stems in your file archive. Otherwise you have to get those from your sound person. Or have those made.
• It is possible to use up-mix software, with varying results. Up-mixes should be reviewed carefully if attempted, to make sure they do more good than bad.
• There is no reason why we can’t simply use your stereo mix (sometimes referred to as a 2.0 mix) on your DCP. Sometimes that works for certain projects and rarely rejected.
• It is our opinion that a well mixed stereo track is better in most cases than a jury rigged and/or badly executed surround mix, fake surround mix, or unattended software up-mix.
• While there is no “official” loudness standard for short or feature DCPs, we’ve found the best results to be between 70 and 82 leq(m) as measured average over the entire run time of a project. We also recommend a maximum peak of any individual mix track of no more than -1 (1 db below the maximum digital peak of 0).

Ideal Masters For DCPs:

• A self contained Quicktime file (Ideally of the entire project in one reel) – such as ProRes HQ, ProRes, DNX, with embedded audio. Square pixels, no un-squeeze/stretch needed.
• We can accept files with extra material, such as bar/tones/slate/textless and extra audio tracks if that’s all you have on hand. We cut off all the extras for the DCP and use just the main sound mix.
• If you are generating a fresh export just for the DCP, please add 10 seconds of black to the tail. It’s optional but helpful for good reasons not really worth explaining. We do cut it off before making the DCP.
• Any subtitles need to be burned into your picture on your end.  
• Also accepted are DPX/TIFF image sequences with separate audio tracks. Please discuss with us first, though. Any subtitles need to be burned into your DPX or TIFF on your end.
• Separate audio is preferred as a the intended or backup to audio on the Quicktime.
• If separate audio, it is ideal to have some kind of audio guide track on the Quicktime file to aid us during our re-sync of your mix. The guide track does not have to be the final mix as long as the dialogue sync is generally valid in the guide audio track.
• Sound Mix tracks (if separate from picture) are 24 bit WAV or AIF files. 16 bit files are acceptable if that’s all you have.
• It’s better if the provided audio tracks are at the same frame rate as the picture master. For example, 23.98fps projects should have 23.98fps audio. If we determine there is mismatch, we can usually adjust it, but it helps if what you give us already has a matching frame rate.
• A 5.1 mix should be single mono/discrete track per track of mix.
• So a 5.1 mix would have 6 separate files, one each – Left, Right, Center, Lfe, Left Surround, Right Surround and labeled in a way that we can identify what is what.
• Or a stereo or LT/RT mix would have one stereo file or 2 single mono/discrete files of left/right.
• If you have both a solid 5.1 and stereo mix, we only want the full mix 5.1 tracks. We do not need any of the split audio tracks. For example we do not need the DME or M&E. tracks to make a DCP. Better to not give us extra tracks if at all possible.
• Other okay sources: HDCAM SR, HDCAM, D5 (though require an extra steps of digitizing and/or conversions).
• Not Ideal: (due to lower quality and extra steps required): H.264, Mp4, 720p, Standard Def, Blu-ray, DVD.
• Standard Definition (SD) source adds challenges. Expectations may need to be managed, as there is much less image real estate to work with — and it has to be scaled up significantly in size as well as frame rate converted in most cases.  In the case of 29.97 SD material it also often has a distinctively interlaced look that might need adjustment.
• Audio sources that are not ideal are AC3 or MP3.
• We do not accept un-exported workstation projects form any platform.

DCP Hard Drives, Link And / Or Upload Options:
In the last few years, “hand-off” decisions for finished DCP have become more complicated as there are now numerous methods of delivery, when in the past, there was mostly one. In terms of which method to use, you are at the command of what any venue or festival is willing and able to accept. Still most common is a hard drive, but with further decisions. It’s not 100 percent possible to satisfy every future situation with just one choice. Also practices vary slightly if the project is feature length, or short. For each screening situation of distribution handoff, you need to get guidance from the theater, festival or distributor and hopefully they can email you a spec sheet that you can digest yourself and/or forward to us. If information is sparse, here are some common scenarios:

Feature Length:

• CRU drives: From a 2020 perspective, these drives might seem big, clunky and look like old technology, CRU drives (pronounced C.R.U. or “Crew”) are your best bet, especially if you have no information to work with and could only choose one option without knowing future needs. These are still the go-to standard for delivery to a commercial movie theater for if your film isn’t part of a large distribution chain. A CRU is not something you can connect to your own computer unless you have special hardware. Also they are usually  formatted as Linux EXT-2 (or 3), unless requested otherwise.  Like any drive, these drives are worth retrieving from the theater or festival for the future screenings. Or they can be erased and re-used for revisions or future projects. More than one project can live on the same drive as long as there is enough drive space to hold them.

• One slight advantage of CRU drives is that they have a “built for warfare” look and feel and are transported in padded packages or cases. People take them more seriously and tend to handle them with more care than a portable USB drive, because they look important. Plus these drives are big enough to handle good sized labels with detailed specs about the film and the drive. While the go-to standard, there are exceptions out there and CRUs won’t work for every last theater or festival, just most all of them. In terms of cost, they are about double the cost of the next cheapest option.
• Next cheapest option… Portable USB drive. Relatively inexpensive, and are more likely to be formatted in Windows NTFS, but EXT-2 is certainly possible. Mac formatted drives are going to be a deal breaker in many theaters. What the recipient can and will accept for drives and drive formats is completely at their control — meaning, what they say they are able to accept. Other drawbacks is that USB drives may not be taken as seriously and are more likely to be tossed around, or dropped. Abuse like that can knock them out of service. Also the USB connections of “cheap” portable drives can’t take a lot of abuse.

• USB- Flash/Thumb/Sticks. Cheaper as well and can be formatted as requested but generally not viable for large large files of feature length DCP. Even though large enough flash drives can be purchased, you are more likely to get resistance because the ingest into the theater systems from a flash drive is usually slower from hard drive. Also since so small, labeling is challenged. We use flash drives that accept a stringer and then we attach the stringer to a toe-tags label. Other negatives, they are easy to lose, easy to roll over with a chair or accidentally sent through the wash.
• Downloadable links are possible and we certainly have that capability, but can be a bit tricky. Mainly, you have to have an agreeable recipient. Presently not a lot of theaters are capable/willing to work with links or other methods of online file sharing. The files are large and require both the sender and recipient to have very fast internet. It is more likely that a festival will organize uploads/downloads on their own than directly at the theater. When asked to make a link our go-to service is “Filemail” as it has a robust upload/download interface that takes advantage of best available bandwidth. The other main advantage of Fillemail is that when using its interface (and unlike web browser services) it does a great job of handing a folder of files, without taking the time to zip or making an enormous unsupported zip files that will never unzip after a lengthy download. DCPs are a folder of files with a specific folder name that needs to stay in tact as a folder. Several other common cloud/ file share services struggle or are clunky in dealing with a folder of large file.

• Uploading to a festival or theater via “their” server or file sharing service. Directly to a theater is less likely. Directly to festivals is becoming more common. If the recipient accepts films this way, they have hopefully worked out the pitfalls of folder based file sharing. We have the capability to load to most servers. As with all of these options, it’s more in the hands of what the recipients allow.

• Considerations for International delivery: Online file delivery has lots of good arguments for international destinations since the extended shipping time and potential customs delays are removed. But you need an agreeable recipient with fast enough internet access.

Short films/Trailers:

• USB- Flash/Thumb/Stick are the most common way to get a short to a theater or festival on physical media. Since the films are shorter and the size of the files are smaller, Theaters and festivals are usually agreeable, even if the ingest time is a little slower. In a couple of rare instances we’ve seen festival insist on a CRU drive for a short. As with all examples, it’s all in the hands of the recipients.

• Links and uploads are sometimes accepted for shorts and are more feasible than features, since the lengths are shorter and so the files are quite a bit smaller (compared to features).

Notes About Travel Hard Drives You Send / Hand Off To Us:
Here are a few friendly suggestions that will keep everything flowing and help you avoid the avoidable:

•  Whenever possible, please supply your material on a hard drive with a USB3 connection. We support others, but this is the most straight forward.
• If your drive requires a power supply, we need you to send that along with the drive.
• Please remember that hard drives are a delicate combination of mechanics and electronics and don’t do well when handled roughly or dropped.
• If shipping the drive to us, please pack it for a bumpy ride with proper padding. Original packaging makes a great inner shipping package. Then more.
• If you are hand delivering a hard drive to us, packing it for the trip is a very good idea. More than once has a hard drive been lost to an unexpected fast stop in a car ride causing a hard drive to fly from the passenger seat to the passenger floor. Know what we mean?
• Even with most proper of handing drives sometimes fail at inopportune times. Most all of the time, they are fine. But… drives can fail in transit, they can fail while sitting on our worktable, they can fail on their way back to you. Sometimes without reasonable explanation.
• So we are urge you—if at all possible, please don’t send us any files we don’t need or files that you can’t afford to lose in a drive failure. Plus, extra and unrelated files also adds potential confusion.
• Ideally the drive we get from you should has only exactly the files what we need on it for the DCP. Please don’t send your “only” copy of the film or a drive that doubles as your backup of your entire operation. If the drive must contain other material, please consider sequestering all unrelated material into a folder that is called something like “do not use” or “ignore.”
• Please label the drive and the drive’s box and with your name, company name and phone number.
• Please label the project files and folders on the drive with a name that we are aware of. Something that would make sense to someone who isn’t intimately familiar with the project.

Upload elements via Internet rather than sending/hand off on a hard drive:

• Master files for DCP can get very large. If you have fast internet, we do as well,  and web based file transfers  file might be reasonable, perhaps 200 gigabytes during one business day. Unless you are just down the street and then hand delivering the files will be faster. If sharing large files, back-time by at least one day and allow for time to recover from errors or the need for a second try.
• Uploads are also okay for short projects, or separate audio coming from a different location or for small patches or fixes.
• Better/faster/easier is for you to use link via our Filemail account: https://tree-falls-post.filemail.com
• it’s easy to use. You do not need an account. Just fill in the form and drag the file/folder and hit send.
• If you have material already on the cloud elsewhere, it MUST be set as a downloadable link. It will not work for us if it just is a “share” or a system that requires a login or if we need to start a new account somewhere. There are a surprising number of competing files sharing systems out there and it is not possible for us to have an account with all of them. So we don’t.

Miscellaneous:

• Our “house standard” for head and tail on festival bound and screening DCPs is to add 2 seconds of black and silence before first frame of picture and 2 second black/silence tail after last frame of picture & credit roll. This will satisfy the requests for padding that we see from some festivals.
• Padding is reduced to 1 second head/tail on trailers.
• If your DCP is going straight to distributors and intended as a distribution master, we do not pad the head or tail.
• It is perfectly fine and useful to include your bars/tones/slates/2-pops and such in the media you provide us. In our process, we will remove all of that and add a clean head and tail.
• If you have a picture master already prepped with lots more audio tracks than needed and separate WAV Files, it’s okay. We will sort it out.
• We are unable to support add Subtitles unless you (or we) burn them into the picture before the conversion to DCP.  Also many festivals and some theaters insist on the burned-in method anyway.
• DCPs cannot be “revised” or changes inserted into them, if any changes are needed they need to be re-done.
• Sorry, we do not support 3D projects.