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Low budget DCP

Today there are several tools for making a DCP yourself and some of them are even free. I’m not familiar with all the tools that are around (remember i work in a cinema, not in a production studio). Nevertheless i picked up a few things worth knowing.

First of all: there are Plug-ins for video editors (like Wraptor for Adobe Premiere) that pretent to make a DCP from your edit. This is a very bad choice to make your DCP, because at least half of the DCPs i get that are made with these programs do NOT play on cinema equipment. I get some reports from people who do have good results using DaVinci Resolve, but i received a non playable DCP as well. So you might go that way if you really want, but you better test before you drive.

Second: Checking your DCP with a computer software DCP player (like EasyDCPplayer) is only good for checking if your picture and sound have turned up in the right shape in the DCP. You need a big high quality monitor, a sufficient speaker setup and sharp vision for this. You can use the Verify tool in DCP-o-matic Player to check integrity of your DCP. But be aware: if EasyDCPplayer plays your DCP and DCP-o-matic Player checks okay it does NOT mean it will play flawless on cinema equipment. See rule number one on my DCP page: If you can not test in a cinema do not try to make a DCP yourself. Try to find a reliable DCP studio, ask colleagues for good references. If this is too much of a hassle for you then you better skip this page and send a good video file instead (think ProRes422LT and the like), ask the theatre or festival that you will send it to which format they prefer.

DCP-o-matic

Now: It’s possible to make a DCP yourself these days. You will be able to make a screening copy that is perfect to show publicly if you stick to the rules. But be aware it probably will cost you time and efforts to get there. I have had good results with DCP-o-matic. It’s free, Open Source and has a good manual. Read it!

To help you along a little after reading the DCP-o-matic manual here are a few tips and additional remarks when using DCP-o-matic. First: Set some preferences. Keep default settings but change only:

Please do not select or alter the other options until you get more experienced and knowledgeable, they can easily get you in trouble.

Now you are set to start making a DCP. Following my hints we will be jumping back and forth through the DCP-o-matic interface, from Content tab to DCP tab and back. I hope the pictures (from MacOS) will help you. To enlarge a picture hover your mouse pointer over it. The screenshots might be a little different from more recent or older versions of DCP-o-matic, but you will get the point.

colour conversion selection

You start a new project choosing New from the File menu. Using the Add file(s)... button you select your edited film file. Wait for DCP-o-matic to analyze your film file. DCP-o-matic usually picks the correct colour conversion. Please check it and change the Colour if necessary. Please read the manual first. If you are unsure it may be wise to first try different settings on one or a few short part(s) of your film and check those in a test screening.

video container selection

Next important part is: choosing the right aspect ratio. First read the aspect ratio page if you didn’t yet. If your film is a HD movie (1920 x 1080 px which is 1.78:1) or Flat (1998 x 1080 px which is 1.85:1) it’s best to put it in a Flat DCP. If it’s Scope (2.39:1 or 2.35:1) it should be in a Scope DCP. If it’s something else: read the aspect ratio page. Knowing this go to the DCP tab in DCP-o-matic and at Video Container select DCI Flat (1998x1080 = 1.85:1) or DCI Scope (2048x858 = 2.39:1).

video scale selection

Next go back to the Content tab and the Scale option. Start with to fit DCP The picture of your video should fill the Preview window top to bottom, except when it is extremely wide (Aspect ratio above 2.39:1). If this is not the case you have to alter a few settings. Begin with selecting custom. Your video might have a non-standard aspect ratio, choose one that comes close. Fill in this aspect ratio in the window that appears when selecting custom. If your video does not have black borders you can fill in its dimensions at Set size. If you don’t know what the dimensions of your video are, open it in Quick Time and hit Command+I (or use a similar method) to get this info, most likely it will be the pixel size. That should do the job. Next use the Crop options to get it right. Find a bright frame in the Preview window to have a good view on what you are doing. Be careful not to stretch or squeeze your picture, best check is on a circle in the picture. Maybe changing the Container option in the DCP tab can help finding the right settings.

video scale selection

When you're ready DCP-o-matic will tell what it will do, you’ll read it under the Range option. Next go to the preview window on the right. Hit Play to see if everything looks as you want it, press play again to pause and move the dot to skip through the video. Make adjustments to the settings as needed.

video scale selection

Also make sure the sound settings are right. For this you first go to the DCP tab. At Channels select 6 - 5.1, or something else if you wish.

6 audio channels

Go back to the Content tab and next to Audio tab. Then check if all your audio channels are mapped correctly. Always 1 = Left, 2 = Right, 3 = Center, 4 = Sub/LFE, 5 = Left surround, 6 = Right Surround. If you need more channels, stick to these DCI specifications

mid-side selection

Please read the sound page first. If you only have a stereo mix and there is dialogue in it do this: Go to the DCP tab and then Audio. Go to Processor and select Mid-Side decoder. This will add a Center channel. You can use the method described in the manual as well. If your film has ProLogic (LtRt) sound and you are sure the theatre sound system can decode this, you may leave the Processor option untouched.

gain adjust

Use the Content tab, Audio and use Gain to bring it below -3dB. Hit Show graph of audio levels. This can take some time! Check all Channels (if you used the Mid Side decoder you should have Left, Right and Center) and see if none peaks over -3dB. Use Gain to correct and see the result inmmediately. For features and shorts i advice to set peaks somewhere between -3.8dB and -4.0dB, for pre-show content like trailers, advertisements and the like i advice to aim for -3.2dB to -3.5dB. With these settings your DCP will have around the same level as most DCPs of that kind. By doing this the chances that your DCP will be played too loud or too soft will be smaller.

timing

If the first and or the last frame of your video has image, this is the time to add 3 or 4 frames of a black picture of the right resolution before and or after the video using Add file(s). If your video has more than 3 sec silent black at beginning or end, trim it using the Timing tab. Changes made here only take effect when you click Set. Check your settings in the Preview window!

subtitles

I have little experience on using subtitles other than from DVD-rips. Please read the manual. As far as i can see there are three possibilities:

At Stream choose the subtitle language you wish to use for this version of your DCP. At Language choose this language also, it will put the correct code in the CPL (to be discussed below). You can resize and shift the subtitles using Offset and Scale. Remember that things look pretty different on a big screen. And keep away from the very edge of the picture. Read about Title Safe Area on the aspect ratio page. With (Fonts and) Appearance you can alter the look of the subtitles, even the colour. Again, you can check things in the Preview window. Burn subtitles into image does exactly what it says. As a projectionist i advice you to not select this. Seperate subtitles will make it possible to shift subtitles in difficult screening situations. But be sure you use a recent version of DCP-o-matic. In older versions certain subtitles types (like those from DVD rips) did not show in projection unless burned in. If you check your DCP in a software player (like DCP-o-Matic Player), subtitles might not be shown correctly. Again the only valid test is in a cinema.

name details

In the DCP tab first set the Content Type: Feature for films over 60 minutes, Short for films under 60 minutes. Do not select one of the options below Advertisement. Some cinema equipent can not handle those. Next set Language for the main spoken language in your film. Don't check this if your film has no dialogue. If you want to fill in something at Metadata Facility or Studio, first check the already used codes on DCNC. Do not check Encrypted except if you know what you are doing. (Read the DCP page) Click Copy as name and correct if necessary. This name is what cinema people call CPL. This is what we see and derive info from, so getting this correct is important.

Now everything is ready for making the DCP. From the menu choose Jobs. If you select Make DCP in batch converter it will allow you to work on a next project in DCP-o-matic, while the batch converter will be busy baking the DCP. Have patience and book a test screening in your cinema. Read on the DCP page what you need for that. If in the test screening your DOP detects quality issues in the picture, you may give it another try with a higher setting of JPEG2000 bandwith at the DCP tab but stay well under 240 or your DCP may cause serious playback issues on cinema equipment. If you need to make a change to the sound or the subtitles, you will discover that editing the original DCP-o-matic project (not starting a new project) will save a lot of time in rendering because it will re-use the unaltered picture file(s) (MXF) of the original DCP. You may also choose to make a VF (Version File), read the manual.

Finally: put only the DCP on the disk or whatever distribution you use. It is inside the DCP-o-matic film/project folder that you set up on preferences or when you started the project. You will recognise it by the format of its name. Something like FilmForFestival_FTR-1_F-178_EN-FR_51_2K_20170206_SMPTE Do not send the whole film/project folder, only the DCP folder! Best is to use rsync, Grsync or ftp for the transfer. If you send your DCP on a disk, the disk has to be formatted ext2 or ext3 to be sure your DCP can be loaded into the cinema system. Look at the ext3 disk page to know more about this. You may also use the DCP-o-matic Disk Writer for putting the DCP on a disk that in the process will be properly formatted to ext2. Be aware the tool will wipe the disk and you can only put one DCP on the disk this way (as far as i know).

Checking

Player Verify

If you have DCP-o-matic you also have a way of checking if your DCP (or someone else’s) that you want to send is not corrupt. Only if you have DCP-o-matic installed in Linux (or you have software that enables mounting ext2/3) you can check the integrity of a DCP on a properly formatted disk (ext2 or ext3). Start DCP-o-matic Player and open the DCP. Let it work for a while until it’s ready. Go to Tools and choose Verify DCP... After a while a pop-up will tell you if the DCP is okay or what is wrong. I get reports that every DCP that has been checked okay by DCP-o-matic Player does play on cinema equipment. (For the scientists among us: It remains true until falsified) If you use Linux you may also use the command line tool dcp_inspect from Digital Cinema Tools to check if the DCP on the disk is okay. Checks will tell you if the DCP is built correctly, it will not report faults in video, subtitles or audio. Please read the DCP page. Consider donating to the DCP-o-matic project.

Henk Rhebergen, updated june 2024