DIGITAL CINEMA MASTERING 101 : DCP’S Done Right

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DIGITAL CINEMA MASTERING 101 : DCP’s Done Right

DIGITAL CINEMA PACKAGES ( DCP)

You pour your heart and soul into the movies you make. The passion of storytelling drives you to get the best possible image up on that screen for the audience to enjoy. With film as a physical medium falling out of common use and Digital Cinema taking over, it’s important to understand how to best take advantage of this new technology, and choosing to have the mastering of your film to digital cinema done right.

WHAT IS DIGITAL CINEMA?

Digital Cinema refers to the use of digital technology to display your movie on a theatrical screen. Digital projection accounts for about 80% of movie screens in the U.S. The rest are expected to make the transition to digital within the next 18 months. There are many advantages of digital cinema including consistent image quality and reduced cost. With most movies now being shot digitally, an all-digital workflow makes sense. You can make 50 or 1000 copies of a digital print without generation loss. And there is no potential dust or scratching in the digital process; which means your hundredth screening will be just as pristine as your first.

WHAT IS A DIGITAL CINEMA PACKAGE (DCP)?

In the way that a film print comes as rolls of film contained in cans, a Digital Print exists as data stored on a hard drive. A Digital Print, known as a Digital Cinema Package (DCP), is a movie stored as a group of digital files that are transported to theaters on a hard drive. The files are then copied to the theater’s Digital Cinema Server-a computer that stores, reads, and plays back DCP’s. From the server the movie is played back and projected onto the screen. A DCP is what is used as the content in all digital cinemas for the highest quality playback. For a number of reasons a properly mastered DCP would have superior image quality to everything else (Film Print, HDCAM, Blu-ray…)

As a film maker, why should I exhibit on a DCP over any other format?

The top 5 reasons are:

1) Digital Cinema has a broad Acceptance: Nearly all cinema screens will be Digital by 2015. In fact 84% all the screens in the US have already been converted to digital projectors that play DCP's. The large film festivals like Sundance, Cannes, Berlin, Telluride, SXSW and many more prefer a DCP as the exhibition format of choice. A DCP would also be required as a submission to AMPAS for an academy award consideration. Roush Media: Digital Cinema Packages 2

2) Huge cost savings for DCP mastering and distribution compared to Film Prints, even tape. The cost of a recording a negative and print from the DI data is apx $30,000 to $45,000. After that each film print will run you $1,500 to $2,500. A DCP that is a digital copy on a hard drive (duplicates) would cost somewhere in the range of $150 to $650 for the same thing.

3) A DCP can have superior image and sound quality over everything else for commercial exhibition ( Film, tape, Blu-ray). When a film release print is made because of the optical generational loss, the resolution is often said to be only about 1K. A DCP will be a digital copy of the DI source (DSM) at least 2K and will look like what the filmmaker indented and viewed in the DI suite.

4) A DCP is Highly Reliable and is a less fragile media then film, or Blu-ray disk. It is easier to ship than film and when it arrives at the theater the server will hash check the data integrity during the ingest process so that once it is on the server and you have a valid KDM if encrypted, you will not have any problems playing it back. With a Blu-Ray Disk you just have a consumer player that cost a few hundred dollars reading a optical disk that could have defects you will not know of until your screening. That is a disaster waiting to happen.

5) Unlike film, a DCP will give you perfect digital copies for your exhibit at the same quality on the 100th screening as the 1st.

WHAT ARE THE SPECIFICATIONS FOR A DCP?

Digital Cinema Packages have fairly strict specifications set forth by the Digital Cinema Initiatives (DCI) and ratified by SMPTE. In order to ensure your DCP’s compatibility with Digital Cinemas around the world, it must comply with the DCI specifications. Most movies can be converted to match these standards, but it is a good idea to plan ahead if you intend to screen in a Digital Cinema. The specifications regulate color and bit depth, resolution and aspect ratio, compression and data rate, frame rates, audio, subtitles and captions, and encryption of DCP’s.

1) COLOR AND BIT DEPTH Roush Media: Digital Cinema Packages 3

One element of Digital cinema that is DCI specified is the color reproduced by Digital Cinema projectors. Most modern displays (TV’s, computer monitors, cell phones, tablets) reproduce color in a color space known as RGB. Digital Cinema projectors, however, display what is known as XYZ color. The Digital Cinema XYZ (DCI XYZ) color space is also much larger than most RGB monitors can display and much closer to the range visible to the human eye. So, one big reason to prepare your movie in advance for Digital Cinema is to take advantage of the large color space available. Instead of color grading your project on a monitor, it would be ideal to see it graded on a projector that can reproduce the same color that will be available to your audience in a theater. This will give you the most control over the images your audiences see.

Chart 1.1-CIE 1931 This graph shows the range of color visible to the human eye. The smaller interior triangle is the Rec709 gamut. The larger interior triangle represents the Digital Cinema color space.

The main difference between RGB and XYZ is the mathematical way that values are represented. RGB has three chrominance values-one each for red, green and blue. XYZ has two chrominance values (X and Y) that represent a color on the CIE Chart. The third value (Z) represents luminance. XYZ and RGB can and do actually represent the same color values.

During the grading process movies exist as RGB, so in order to fit the RGB values into the same gamut as DCI XYZ they need to be graded in the color space known as P3. P3 is an RGB color space, but has the same color values and range as the DCI XYZ space. Because the two are represented differently, conversions have to be done between the grading process and the DCP encoding so the DCP can be viewed properly. Under proper conditions that conversion is lossless-the colors represented should be identical when properly displayed. Roush Media: Digital Cinema Packages 4

Managing these color space conversions is essential when creating your image files. To guarantee that your movie will be projected correctly on the big screen the use of Look Up Tables (LUTs) or Gamma Matrices are applied to convert from Rec709 or P3 RGB to XYZ during the DCP creation.

Another element that affects the color reproduced in Digital Cinema is the bit depth of the images. DCP’s are created with 12 bits per color channel (12 each for red, green, and blue). This means that each of the red, green, and blue channels can individually reproduce 4096 values between black and full luminance. When you consider every possible combination of those values you get the 68,719,476,736 colors available in the Digital Cinema color space. This gives DCP’s a great amount of dynamic range and means that there are an immense amount of colors they can reproduce. The table below compares bit depths and their colors, along with some examples of technologies that employ them.

Table 1.2-Bit depth and color

Bits per Steps per Total Reproducible Examples channel channel Colors 1 2 8 2 4 64 3 8 512 4 16 4,096 5 32 32,768 6 64 262,144 7 128 2,097,152 8 256 16,777,216 (Million) DVD/Blu-ray, 5D, DNxHD, TV, computer screen 9 512 134,217,728 10 1,024 1,073,741,824 ProRes, DNxHD(X), DPX 10bit (Billion) 12 4,096 68,719,476,736 DCP’s, ARRIRAW, REDCODE RAW (Billion) 16 65,536 281,474,976,710,656 F65 RAW, DCDM, DSM (Trillion)

This chart shows the 8 colors that may be reproduced with one bit per color channel. With one bit the channel can either be turned off (0) or turned to full luminance (1). Roush Media: Digital Cinema Packages 5

Chart 1.3-One bit per color channel

R-0, G-0, B-0 R-0, G-0, B-1 R-1, G-0, B-0 R-0, G-1, B-0 R-0, G-1, B-1 R-1, G-1, B-0 R-1, G-0, B-1 R-1, G-1, B-1 Black Blue Red Green Cyan Yellow Magenta White

Higher bit depths allow for changes in color to be smoother and give the ability to reproduce a more accurate representation of the intended image. They also give you more room to manipulate the image without artifacts and banding. The image below represents the steps available in 1, 2, 3, 4, and 5-bit color for the red channel: starting with the channel turned off (black) on the left, and ending with full luminance (red at full luminance) on the right. The 12 bits available in Digital Cinema are significantly more than can be accurately represented here.

Chart 1.4-Red Channel bit depth

1 bit (2 steps)

2 bits (4 steps)

3 bits (8 steps)

4bits (16 steps)

5 bits (32 steps)

If you imagine identical charts for the green and blue channels, every possible combination of those steps mixed together and alone will give you the total number of colors available with each bit depth. Roush Media: Digital Cinema Packages 6

2) RESOLUTION AND ASPECT RATIO

Another element specified by DCI is the resolution of DCP’s and the aspect ratios that relate to those resolutions. DCP’s can be created at either 2K or 4K. And theaters are required to be able to project your movie whether the DCP is 2K or 4K. A 2K DCP will be scaled up by a 4K projector and a 4K DCP is scaled down by a 2K projector. This means that your movie should always play at the proper size regardless of the screen on which it plays.

There are a few different common aspect ratios to choose from when making a DCP. They are 1.85:1 (referred to as “Flat”), 1.89:1 (also known as 1.90:1 and referred to as “Full Container”), and 2.39:1 (also known as 2.40:1 and referred to as “Scope”). The table below shows the 2K and 4K resolutions relating to those aspect ratios. Each of these is known as a “container size” because all DCP’s should ideally fit within one of these aspect and resolution combinations.

Table 2.1-DCP Container Sizes

Flat (1.85:1) Full Container (1.90:1) Scope (2.40:1) 2K 1998x1080 2048x1080 2048x858 4K 3996x2160 4096x2160 4096x1716

It is possible to encode DCP’s in other aspect ratios, such as 1.78 (16x9), they would just have to fit within one of the container sizes. For example, a 1920x1080 (1.78) project can easily fit within the 2K “Flat” package with some slight pillar boxing. A 1.78 image can also usually be resized and cropped to 1.85:1 without losing relevant information. And 2.35:1 images are often fit into the 2.40:1 container either by pillar boxing or cropping the top and bottom. The chart below shows the relationship between the aspect ratios.

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Image 2.2-Aspect Ratio Chart

3) COMPRESSION AND DATA RATE

DCI also specifies the type of compression and data rate necessary to faithfully represent images on movie screens. The files that make up the media contained in DCP’s are MXF containers (.mxf) with JPEG 2000 encoding. MXF stands for Material Exchange Format and is a common "wrapper" file format for video and audio. It is the native media format in Avid editing systems and is gaining support in many camera systems. JPEG 2000 encoding is a wavelet-type compression, which is considered lossless. And all DCP’s are compressed at a maximum of 250 Megabits per second. This means that when your movie is displayed from a DCP it should be visually indistinguishable from your final color graded images. DCP’s are compressed at a maximum of 250 Mbits/sec with Jpeg 2000 encoding (wavelet/lossless) and contain 12 bits of color information (4,096 steps/68,719,476,736 colors).

Blu-rays are compressed at a maximum of 35 Mbits/sec with h264 or mpeg2 encoding (both lossy) and contain 8 bits of color information (256 steps/16,777,216 colors).

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4) FRAME RATE/3D

DCI also regulates the frame rates for 2D and 3D movies. There are a variety of potential frame rates that a DCP could play at, however, 24 frames per second (fps) is the most common. And in order to ensure compatibility with all Digital Cinema Servers, a 2K DCP will need to play at either 24 or 48 fps and a 4K DCP will need to play at 24. Conversions can be done for projects shot at 25, 30 or 60 fps so that they meet those specifications. Even projects shot at 23.976 fps require a slight auido conversion to play at a true 24 fps.

A stereoscopic or 3D DCP actually shows 48 frames per second for a 24 fps movie. This is because each frame in a 24 fps 3D movie actually consists of a left eye and a right eye, meaning that you have double the frames to display for 3D. Standards have not yet been set for high frame rate (HFR) DCP’s and the technology is still being developed to properly display them.

5) AUDIO

DCI specifies audio for DCP’s as PCM audio that remains uncompressed through the entire process. The audio for a DCP is usually 5.1 surround sound, but stereo and 7.1 surround are also available options. The mix is split into mono waves at 24 bit and 48 kilohertz (kHz) and to be included with the picture delivery. They are then encoded as uncompressed PCM files with the DCP. Because DCP’s run at a true 24 frames per second, projects edited in 23.976 fps need a slight conversion for the audio to sync with the picture properly.

6) SUBTITLES AND CAPTIONS

According to the DCI specifications, DCP’s can include burned-in subtitles or alternatively, a subtitle track which is separate from the picture and synced based on timecode. The subtitle track is then interpreted by the projector and displayed on the screen as the movie plays. Captions work similarly, but instead of being displayed onscreen they are displayed on devices provided to individuals by the theater. Subtitles and captions can be included with your picture and audio delivery as an XML file.

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7) ENCRYPTION

DCI also allows for DCP’s to be encrypted (AES 128bit) in order to protect your content. An encrypted DCP cannot be played or modified unless access to it is granted via a file known as a Key Delivery Message (KDM). KDM’s are generated and distributed to theaters along with encrypted DCP’s allowing a theater to play a specific DCP for a specific range of time on a specific screen. In order to create a KDM, two things have to happen-the theater has to provide its server’s certificates and the range of time that theater will be allow to play the movie has to be determined.

The added expense is required for studio & theatrical broad released films, but may not be the best choice for festivals and special screenings for a small indie film. A film festival would prefer it to be unencrypted for easer scheduling and playback. Even a DCP that is not encrypted has a number hurdles that must be overcome for it to be pirated.

For example,

1) To access or view a DCP, you will need special systems or software (Linux EXT file systems, Jpeg2000 MFX decoding of DCI compliant content). 2) Once you have access to the files they will be in XYZ color space. These files need to be converted correctly to be viewed without everything looking really bad. 3) Each Digital cinema server is designed to only allow ingesting of a DCP and cannot export the CPL (Composition Playlist). This will not allow it to be moved to another server without coming from the source Hard Drive.

WHAT TYPE OF FILES CAN BE USED TO MAKE A DCP?

Theoretically, almost any type of image and sound file can be used to generate a DCP. You could make it from a ProRes QuickTime, various tape formats, a DPX or Tiff sequence, or even RAW camera formats. But, the thing to remember when preparing your files is that the DCP will not be any higher quality than the material you start with. For example, if you were to make a DCP from a DVD your DCP might technically be 2K, but it will not increase the clarity or color information in your image-it only increases the size.

So, the best practice here is to start with files that are at or above DCI specifications (2K, 12 bit uncompressed, P3 gamut, 5.1 audio). In order to make the best use of the color and range that you have available in Digital Cinema, a DCP should be generated from files color graded in P3 in a DCI theater. A LUT conversion can be done but in most cases it will not take advantage of the larger color gamut of P3 and not be as good as if the film was graded in P3. This is especially important with wide color Roush Media: Digital Cinema Packages 10

gamut cameras if the original camera material is 12 bits or more, like the RAW formats available with the ARRI Alexa, Sony F65 and RED.

Generally, after a movie is color graded, it will be exported to an uncompressed image sequence like DPX or Tiff. A Digital Cinema Distribution Master (DCDM) is often created in preparation for a DCP with specifications set by DCI. The DCDM consists of 16 bit Tiff files at the intended resolution in DCI XYZ color and the final 5.1 audio mix as separate mono wave files at 48 kHz and 24 bit. Any necessary subtitle files or other program data is also included.

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HOW CAN I CHOOSE THE RIGHT FACILITY?

Software and systems are is becoming available at lower costs. Many companies are beginning to provide Digital Cinema Mastering services creating a more competitive market. But, not all Digital Cinema Packages are created equal and you need to make sure that you choose the right facility to master your film to a DCP. You have to take into account whether or not the facility has adequate technology, knowledge and experience.

There are many low cost solutions, but evaluate your options carefully. Companies can say that they provide a fast, reliable and low priced option for creating and distributing DCPs, but they may not have the engineering, tech support and knowledge to make sure that there will be no issues with your DCP when it arrives at the theater. There are many things you need to look out for when your DCP is created with low cost services or software systems.

Things to watch out for:

-Color conversions to XYZ may not be 100% accurate. The RGB to XYZ matrix can be incorrect and make your image look milky, washed out, tinted, or worse.

-DCP’s run at true 24 fps. This means that generally the audio need to be retimed in order for it to sync correctly. When this is not done right you will have sound sync and pitch issues.

-The low cost software options often do not encrypt DCP’s, and often cannot create 3D or 4K DCP’s.

-DCP’s made by low cost software may or may not be DCI-compliant. Which means it may work on one server, but not on others.

-In the image pipeline use of poor tools and techniques can introduce extra compression, artifacting and lost image detail & color information. The goal should be to produce the best looking DCP not just any DCP.

-After the DCP is created, the copy onto the hard drive that is DCI compliant then should be hash checked, ingested it into a server to verify it, and a full Quality Control pass done in a DCI theater. If this is not done your first screening will be a gamble.

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WHY SHOULD I CHOOSE ROUSH MEDIA?

At Roush Media we want to give our clients the best possible experience with post production. We don’t cut corners on quality and we won’t break your budget. We will manage your image so it looks great from start to finish.

Making a DCP with us is a great choice. As a DI facility we specialize in color and are happy to grade your movie with you in a calibrated DCI theater where the DCP will be shown. Grading in our Digital Cinema Theater allows you to maximize your audience’s viewing experience and make sure your vision is what makes it to the screen. We quality control all of our DCP’s (whether you grade with us or not) in the same DCI- compliant theater to ensure that your movie holds up when projected on the big screen. Our Digital Cinema server is identical to the ones found in theaters ensuring that if it plays back for us, it will play back for the theater.

We compress DCP’s at the highest possible data rate so your movie retains its perfect clarity and sharpness. We also have the ability to encrypt your DCP allowing you to feel at ease with your project’s safety and satisfying any requirements from distributors. And we are more than willing to provide any necessary KDM’s for theaters to play your encrypted DCP. The hard drives we provide for our clients’ DCP’s have been vigorously tested to ensure compatibility and reliability for transport to your screenings. We will make your DCP right the first time and we guarantee your satisfaction. At Roush Media we will provide you with reliable, superior service to make sure your projects are delivered in a manner that exceeds your expectations.

Here are some reasons why:

1) We thoroughly check the source files (DSM) that are delivered to insure they meet our specs from a quality control standpoint. If there are potential issues that we notice our staff will notify you of the problem before hand to resolve it. 2) As a DI facility and not just a D-Cinema mastering business, we know color. If you have not color graded your film in a DCI theater you’re not getting the best image for a theatrical screening. We have talented colorist and a DCI theater that we can grade your film or trailer in with the correct color space & proper environment. This allows you to see what your audience will see. If your film has already been graded we can convert from Rec709 to P3 (Digital Cinema Color Space) and do a trim pass so you see what it looks like before we create the DCP. If doing it right is important to you and you have not graded your film for a theater environment, we recommend this. Roush Media: Digital Cinema Packages 13

3) Since we are serious about color and know it well, you can be assured that the XYZ Color Conversions we do are 100% accurate. For more accurate color mastering we employ a RGB to XYZ matrix in floating point. This is the math behind a LUT and is much better. 4) As part of the D-Cinema Mastering process if necessary and at no additional cost we will reformat the aspect ratio to Flat or Scope, pull up the audio to sync at 24fps, and convert the color to DCI XYZ color space from the films source. 5) We have the engineering experience and support to provide the studio quality 2K, 4K and 3D encrypted DCP’s that are 100% DCI Compliant and work on all servers. 6) We QC in a calibrated DCI Compliant Theater on a 20 foot screen to give you the peace of mind of what your final print looks like.

We offer the highest image quality and reliability in Digital Cinema Mastering (DCP) for theatrical distribution to cinemas, festivals and red carpet premieres. When you want it done right the first time, on time, looking its best – at a price you can afford; we are your source.

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WHAT DO OUR CLIENTS HAVE TO SAY?

“When I was searching for a company to do the digital cinema mastering for my latest film’s theatrical release I was really nervous. This was new to me so I asked around for a company that would walk me through the process while at the same time giving me the best transfer to DCP for some of the largest screens in America. I contacted one of the biggest facilities to see if they could do the DCP for my film. I was quoted 5,000 dollars to do the DCP. After I sent the film I was told that they could not do it because my frame rate was 30 and needed to be 24. My DP on the project then recommended Roush Media because they could do a frame rate conversion too. I can't tell you how grateful I am for taking his advice. They basically held my hand through the entire process helping me to provide the right files that saved me thousands of dollars and avoided the frame rate conversion. Roush Media not only delivered a great looking DCP on time and for a great price but took the time to listen to me when the big facilities would not! I will definitely use Roush Media on my next project.”

-Steven Scaffidi Executive Producer Ghost Rider Pictures

“Our first stop at Roush Media's door turned out to be a memorable one; the group handled the Digital Cinema Package encoding on our new feature, as well as Blu-ray authoring and also some color correction work on a second project. Each stage of service far surpassed our expectations, and we were doubly impressed with, not only their expressed dedication to detail, but also their commitment to go the extra mile for us in offering options and cost-saving alternatives. As a small independent studio trying to maintain ourselves in the open marketplace, contacting Roush Media was the wisest choice we could have made. We look forward to partnering with them again.”

-Jefferson and Kelly Moore Owners and Executive Producers Kelly's Filmworks Limited

“Roush Media gave the best care and customer service imaginable on our DCP conversion. Our feature film, ‘Lost In Hustle’ had a cinematic release date in South America just days after we found Roush. They discussed technical issues fully with incredible detail to be certain we were all on the same page. They were kind, generous and met our rush deadline which overlapped a holiday weekend with professional and friendly service that is hard to come by. They did a fantastic job and our Lost in Hustle premiere was a great success. We plan to work with no one else but Roush media on our future projects.”

-Didier Chabi Filmmaker