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Authoring Blu-ray Discs

If you don't know what you're doing, HD output can prove a frustrating task. To give some perspective, a minute of uncompressed HD video equals a gigabyte of memory! The answer to this problem is compression. The time has come to empower yourself! By understanding HD compression you will minimize your problems when outputting to Blu-ray. This will save on time and aspirin. In this tutorial, we'll walk you through the process of compressing video for Blu-ray distribution.

The following examples will draw from Adobe Premiere and Adobe Encore, as these are the systems the author has worked most extensively with.

Compressing for Blu-ray is a two-step process.

1. Creating the HD Media File (Encoding and Formatting)
2. Putting it on a Blu-ray Disc (Building and Burning)

The first step can be approached in two ways. You can use your editing platform, Adobe Premiere in this case, or you can use your disc authoring system, Adobe Encore.

For step number one, I recommend using your editing platform (Adobe Premiere in this case) to compress your masterpiece. There are a couple of reasons for this. The editing platform gives more options for output, while encoding within it allows the system to focus all its energy on creating a crisp media file for you. I find the overall quality tends to be better.

If you choose to export your video via the DVD authoring system (Encore), it will be pulling double duty as an encoder and a Blu-ray burner. Remember, you're dealing with HD here. While the encode step happens before the burning takes place, the entire operation puts tremendous pressure on the authoring system. As such the entire process takes a long time (at most a few days,) and that's if the congestion of data doesn't crash the platform. We recommend saving often, and we've experienced greater overall stability when we manually transcode clips before beginning the build process.

In Adobe Premiere click File and then Export, where the drag down will display a series of options. Choose Adobe Media Encoder, as shown (Figure 1.) This will open the Encoder's Export Settings sub screen (Figure 2.) This is where the encoding process will take place.

Adobe Media Encoder is very straightforward and the options are all very accessible.

First you want to choose a codec. The primary video codecs that support Blu-ray are as follows:

• MPEG-2 (Blu-ray)
• H.264 Blu-ray (MPEG-4 AVC)
• SMPTE VC-1
• (Figure 3.)

MPEG-2 (Blu-ray) is the first-generation HD codec and is more akin to the limited 4.7GB DVD format. As such, the quality is compromised.

H.264 Blu-ray or MPEG-4 is newer and much stronger in both quality and efficiency in use of the available bits on the Blu-ray Disc.

SMPTE VC-1 is Microsoft's answer to H.264 (MPEG-4). Due to its reliance on the Windows Media architecture, this codec is only available on Windows-based outputting platforms.

As part of the spec, all Blu-ray players will support any one of these codecs, but for the sake of this example, we will choose H.264 Blu-ray (MPEG-4).

Below the format options you will see the range options (shown in Figure 2.) This refers to the exporting of your entire video or just a part, as marked on the Premiere timeline by in and out points.

As seen in the example (Figure 4.) there are many choices for pixel resolution. Most of your choices are similar. If you're exporting for a movie or home video, 1440x1080 is usually the way to go. You'll notice a small i or p next to the 1080.

The standard HD video mode is 1080i. The 1080 is the vertical resolution of the image, while the i means interlaced scan. Up till recently, most digital video was shown interlaced. The newer format is 1080p. The p stands for progressive scan.

In this case we'll choose 1440x1080i (Figure 5.) Here I chose 1080i because the video was originally shot interlaced.

You'll notice the 29.97 next to the 1080i. 29.97 is the rate of frames per second of playback, or simply frame rate. The frame rate affects how the motion of your video is perceived.

When video is shot, the presets of a camera will provide you with frame rate options. The vast majority of video in North America is shot at 29.97 frames/sec. Film is usually shot at 24 frames/sec. It's important to know what frame rate your project requires, because if it is heavily altered from its original settings the quality of the finished product may suffer.