Making a Digital Cinema Package

The finished Stop/Eject DCP. Not as cool as a roll of 35mm.
The finished Stop/Eject DCP. Not as cool as a roll of 35mm.

Now that huge reels of 35mm film are all but obsolete, Digital Cinema Packages (DCPs) are the new means of getting a film to a cinema. Many top film festivals will only screen off a DCP or 35mm print, and in terms of picture and sound quality and compatibility it is your best option for screening at theatrical venues in general. Much has been written about how you can make a DCP at home for nothing, but having just gone through the process myself for Stop/Eject I’m going to round up some of the best sources of information I came across and enlarge on the area of disc formatting which hasn’t been too well covered elsewhere.

To ensure maximum compatibility of your DCP you need to:

  • convert your film to 24fps if it isn’t already at that frame rate
  • use a standard 2K aspect ratio, 2048×1080 or 2048×858
  • put it on a disc that is EXT3 formatted
  • supply that disc in a Cru Dataport DX-115

I’ve spoken to filmmakers who have ignored many or all of the above and still run their DCPs successfully in cinemas, but I decided to play it safe and do all of the above, except the Cru Dataport, which was a little too expensive. Instead I bought a 500GB LaCie Rugged USB drive and put my DCP on there. Read Knut Erik Evensen’s excellent blog post on DCP delivery for more info on Dataports and USB compatibility.

The formatted drive as seen in Ubuntu, with the DCP files copied over
Step 5: the formatted drive as seen in Ubuntu, with the DCP files copied over

So, here is the process I went through. I was starting out with 25,409 uncompressed 16-bit TIFF files representing each individual frame of Stop/Eject, and six mono 24-bit linear PCM WAV files for the 5.1 surround soundtrack. The TIFFs were in 1080P (1920×1080) letterboxed to an aspect ratio of 2.35:1.

  1. First of all I used Photoshop to batch convert all the TIFFs to the 2048×858 aspect ratio. This is actually 2.39:1 rather than the 2.35:1, so it meant cropping a sliver of the actual picture off the top and bottom, not just the black bars, as well as enlarging the picture slightly. It took my poor iMac about 12 hours to convert the 25,409 frames. I’m sure there’s quicker batch conversion software out there than Photoshop if you hunt around though.
  2. Next I used a free piece of audio software called Audacity to slow down each of the six audio files by 4% so that they will match the images when they run at 24fps. (Stop/Eject was shot and edited at 25fps.) Thanks to Matt Cameron’s blog for this tip.
  3. Then I downloaded and ran OpenDCP, the brilliant free software that actually creates the Digital Cinema Package for you. It’s very simple to use, but check out the help Wiki and Danny Lacey’s seminal blog post to guide you through it. The end result was six files: four XML files and two MXF files, one for sound and one for picture. Encoding at the default bitrate of 125mb/s, which the Wiki says is more than good enough for 2K at 24fps, Stop/Eject’s DCP was just under 17GB, so about 1GB per minute.
  4. Now the tricky bit – copying those six files onto an EXT3 formatted drive. EXT3 is a Linux file system, and is not supported by MacOS. So I downloaded Ubuntu, a free operating system which does support it. (Choose the 64-bit download unless you have quite an old computer.) The downloaded file is a disc image (.ISO) which you can burn to DVD using Disk Utlity (found in the utilities sub-folder of MacOS’s Applications folder). Then restart your Mac, with the DVD still in the drive, and hold down C when you hear the chimes. This will boot up your Mac in the Ubuntu operating system. (You can release C when you see the black screen and Ubuntu logo.)
  5. Once Ubuntu was running, I right-clicked the LaCie Rugged in the list of drives in the lower left of the desktop and chose format from the contextual menu. To get more than the default options, I clicked Disk Utility in the dialogue box that came up. I could now select EXT3 as the file system (leaving the other settings at their default values). When I clicked format, Ubuntu didn’t seem to be doing anything, but after a few minutes the Disk Utility showed that the volume had been created. I could then close the Disk Utility, and drag and drop the six DCP files from another hard drive (MacOS formatted) onto my newly EXT3 formatted LaCie. Apparently you can put these files inside a folder if you want, but again to be extra safe I put them in the root directory.

After completing the DCP I took it to the Courtyard, my local arts centre, where head projectionist Simon Nicholls was kind enough to let me test it. To my very pleasant surprise it worked perfectly, uploading at about real time via the Doremi server’s USB 2 socket and playing shortly afterwards with superb sound and picture quality. Much as I love celluloid, the ease and cheapness of this process are breathtaking, the purchase of the hard drive being the only cost. I’ll let you know how I get on running it at other cinemas.

Making a Digital Cinema Package

How to Create a Blu-ray Motion Menu in Adobe Encore

Today I thought I’d share the process I figured out for creating looping menus in Encore for DVD and Blu-ray. If, like me, you want to do it all from scratch rather than using any of the built-in templates, the process isn’t particularly intuitive, and was sufficiently different from DVD Studio Pro (the software I’m used to) to leave me scratching my head from time to time, but here’s how I did it in the end. I’ll use Stop/Eject‘s main menu as the example. I’m going to assume you already know the basics of Encore and can find your way around Photoshop.

First of all you have to understand how DVDs and Blu-rays (henceforth collectively referred to simply as “discs”) work. They’re not like websites or Flash movies where you can do anything you want; the specifications are quite narrow. A motion menu consists of two elements:

  1. The background, which is a video (typically with audio) that you can create in Final Cut Pro, Premiere, or whatever.
  2. The button highlights, which show the user which button is currently selected. The user will only ever see one of these at a time.

Hang on – background, button hightlights…. but what about the buttons themselves? These have to be part of the background. Yes, you can import your background movie as a Quicktime into Encore and then add buttons to it within Encore, but when you come to build your disc the software will render those buttons into the background movie. All the disc player can deal with is a background movie and the highlights.

I prefer to build my buttons into the background movie in my editing software (Final Cut) rather than add them in Encore, and that’s the approach I’ll outline here.

Another crucial point to understand is that each button highlight can only be one colour. So look at the Stop/Eject main menu below. The button highlights are the white rings. They could not be red-and-white striped rings, like life preservers; they can only be one solid colour.

Stop/Eject's main menu with all the button highlights visible
Stop/Eject’s main menu with all the button highlights visible

So, now you appreciate all of the above you can get started on your menu. The first step for me was shooting and editing the background movie, although for most people this will be a computer-generated graphic rather than something shot with a camera. It’s important to think about where your loop point is going to be so that the menu will loop smoothly.

The following video shows my edited background movie. The buttons were created in Photoshop and added to the movie in Final Cut, before exporting as a ProRes Quicktime (with these buttons now baked in) ready to be imported into Encore.

In Encore I can now create a new menu and use the pick-whip in the properties panel to select my Quicktime file as the source for both the video and the audio. I can also set the loop point in the same panel.

I need to make sure that the loop point is at a place in the video where the audio track is silent or at least is playing a constant background noise – e.g. an air conditioning hum – that will not jump unpleasantly when the menu loops. You’ll notice that my menu’s audio track has a beat or two of silence around the loop point. If you’re using music, don’t start it immediately at the loop point as many players take a fraction of a second to kick in the audio after they loop.

I also need to ensure that all of the buttons have appeared before the loop point. This is because the loop point is the place at which the player will start displaying the button highlight. If your menu loops back to a point before the buttons have appeared, the user will momentarily see the highlight without the corresponding button.

To create the button highlights, right-click (or ctrl-click if you’re using a single button mouse) on the menu and choose “edit menu in Photoshop” from the contextual menu. Photoshop will open with a still of your menu as it appears at the loop point. Annoyingly, this still will be in standard definition even if you’re creating a Blu-ray disc, so the first thing you’ll need to do in Photoshop is to change the pixel aspect ratio to square and re-size the image to 1920×1080.

For each button, create a new group in the layers palette and give it a name that starts with (+). When you go back to Encore it will recognise this folder as pertaining to a button. Within the group, make a new layer and call it (=1)highlight. Draw your button highlight on this layer, remembering that it can only be one colour.

Now we need to pause a moment and consider hit areas. When your disc is played in a computer, the user can select buttons with the mouse. The hit area determines what part of the screen the user must hover the mouse pointer over for the button to be considered selected. This area MUST be rectangular. For each button, Encore will look at all the layers within the relevant group and draw the smallest possible rectangle that will completely enclose all those layers; that will be your button’s hit area.

In my case, right now the only layers in my groups are the white rings which are the button highlights themselves. But what if someone hovers the mouse over the words “special features”? I want the button to be selected then too, so in the (+)special features group I’ll create a second layer (critically, it must be below the highlight layer) and draw a rectangle where I want my hit area to be. I can then click the eye icon next to this in the layer palette so it becomes invisible and doesn’t ruin the look of my menu.

The main menu with the hit areas visible
The main menu with the hit areas visible

Another restriction of the DVD/Blu-ray specs is that button hit areas can’t overlap. Given the restriction I mentioned earlier, that they must be rectangular, you can see from the layout of my menu that it isn’t possible for the hit areas of Play Movie and Scene Selection to include the text for those buttons without overlapping each other. I choose not to compromise the design of the menu and trust that users will soon find the hit area with a quick sweep of the mouse over the whole image.

I save the image in Photoshop and return to Encore. I can now see the button hit areas outlined on the menu. If I click the icon for “show selected subpicture highlights” (see below image) I can see the highlights too. It’s now simply a case of setting the target for each button using the pick-whip in the properties panel.

The Encore interface with the button to view the highlights hovered over
The Encore interface with the button to view the highlights hovered over

When users return to the main menu, after they’ve visited the special features menu, for example, I don’t want them to have to sit through the intro part of the menu again; I want them to go straight to the loop point. So I’ll go to the main menu button in the special features menu and set the target – not using the pick-whip, but through the pull-down menu. I’ll select “specifiy link” and in the dialogue box which appears I make sure to tick the “set to loop point” checkbox.

One final point. The version of Encore I used (CS5.1) has a bug whereby any motion menu longer than 70 seconds will not loop smoothly; a second or so of black will appear each time the player gets to the end of the loop. This issue does not occur in Encore’s preview, only when you’ve burnt the disc. There’s no workaround that I can find other than shortening the menu.

I hope this has been some help to those of you out there who are still burning your films onto physical discs. Let me know if you’d like to hear more about any part of the disc authoring process.

How to Create a Blu-ray Motion Menu in Adobe Encore