Compressor: DVD Compression Settings

[NOTE: I’m just finishing a complete training series on Compressor 4.1. Currently, this is available to subscribers only. After the first of the year, it will be in our store.]

One of the most common compression questions I get is how to compress files for a DVD. I’ve covered this a lot in my video training, but haven’t written about this for several years. This article explains what you need to know using both Compressor 4.1 and Compressor 4.0.

NOTE: DVDs are always and only standard-definition video. Compressing HD media for a DVD always converts it to standard-def. If you need to burn HD media onto an optical disc, you need to create a Blu-ray, or AVCHD Disc. (The HD-DVD format listed in DVD Studio Pro is a dead format that can only be played on a Macintosh, and nothing else.)

WHEN SHOULD YOU COMPRESS FILES FOR A DVD?

• If you are using iDVD to burn movies to a disc, you don’t need to compress them in Compressor.
• If you are burning a single movie to a disc, you can do that in either Final Cut Pro X or Compressor.
• If you are authoring a disc to contain multiple movies, menus, scripts, stories in either DVD Studio Pro or Adobe Encore, then you need to compress your media in Compressor.

COMPRESSOR 4.1 SETTINGS

A new feature in Compressor 4.1 is Destinations. A Destination combines both a compression setting and a job action that does something with the file once compression is complete. In this screen shot, the Create DVD destination is highlighted.

The benefit of Destinations is that they compress and burn a single movie to a disc with one setting.

To apply a Destination, drag the “Create DVD” destination on top of the job.

CHANGE AUDIO SETTINGS

This applies two compression settings and a job action to burn the actual disc itself:

• Dolby Digital (which creates the audio file)
• MPEG-2 for DVD (which creates the video file)

Authored DVDs use MPEG Elemental files, which means that the audio and video are separated into different files during compression, then combined during the final building process of the DVD; a process called “mixing.”

Open the Inspector by clicking the icon (blue in this example) in the top right corner of Compressor, or type Command+4, then click the Audio text button at the top.

All the audio compression default settings are fine, except for three (unless you mixed the audio in a Dolby-certified environment, in which case, leave these on):

• Change DRC line mode to: None
• Change DRC RF mode to: None
• Change Dialog Normalization to: -31

This turns all three of these settings off.

CHANGE VIDEO BIT RATE

Select the MPEG-2 for DVD setting applied to the job, then click the Video text button at the top.

A new feature in the 4.1 update is Automatically select bit rate. This setting is on by default. What this does is automatically set the bit rate for the video file to get the highest quality based on the available space on the disc. However, this setting assumes you are only burning one movie to a DVD. This is the best choice when you are burning a single movie, but not a good choice when authoring several movies to a disc.

NOTE: Keep in mind that if you want to burn multiple movies to a disc, you need to use an authoring program like Adobe Encore or DVD Studio Pro; you can’t use Compressor.

My recommendation, when you need to compress multiple movies to burn to a disc, is to change the compression settings to:

• Uncheck “Automatically select bit rate”
• Set the Average bit rate to: 5.5 mbps
• Set the Maximum bit rate to: 7.2 mbps

NOTE: These settings apply to both PAL and NTSC media.

The rest of the video settings are fine. This allows up to 90 minutes of media on a single-layer, single-sided disc, or up to 3 hours on a dual-layer, single-sided DVD.

COMPRESSOR 4 SETTINGS

In Compressor 4, the changes are similar, but the interface is different.

In the Settings window, inside the Apple folder is Disc Burning. Drag the Dolby Digital Professional and MPEG-2 for DVD settings on top of your clip in the Batch window. (The H.264 setting is only used for Blu-ray Discs.)

In the Batch window, select the MPEG-2 for DVD setting that is applied to the clip, then click the Encoder tab in the Inspector. Click the dark Auto-Sensor just to the right of the Average Bit Rate entry box. (This is only useful when burning one movie onto the DVD.) When this sensor is dark, it is on. When it is light gray, it is off. In this screen shot, it is turned on (dark).

Then, make the following changes:

• Set the Auto-Sensor to: Off (light gray)
• Set Mode to: Two-pass VBR Best
• Set the Average bit rate to: 5.5 mbps
• Set the Maximum bit rate to: 7.2 mbps

NOTE: These settings apply to both PAL and NTSC media.

As with Compressor 4.1, this allows about 90 minutes of material on a single-layer, and 3 hours of material on a dual-layer DVD.

Next, go back to the Batch window and select the Dolby Digital setting applied to the clip. Then, in the Inspector > Encoder > Audio tab, set Dialog Normalization to -31.

NOTE: Yes, I know. This is weird number. But the explanation of how this works would require another article.

Click the Preprocessing tab…

And change the Compression preset to None. This disables light audio levels compression that is being applied by this encoder.

And that’s it.

To learn more about Compressor 4, I invite you to become a subscriber, or check out the Compressor 4 training in our store.