Apple DVD Studio Pro 4 - Manual (Page 63)

• One-pass VBR method: You choose a basic bit rate and a maximum bit rate. The encoder
detects the amount of motion present in the video as it encodes and adjusts the bit
rate appropriately—scenes with motion use higher bit rates (up to the maximum setting
you choose) and scenes with little motion use the lower, basic bit rate. The disadvantage
of this method is that the quality will not be as good as with the two-pass VBR method.
• Two-pass VBR method: You choose a basic bit rate and a maximum bit rate, just as with
the one-pass VBR method. The difference is that the encoder makes two passes through
the video to encode it. The first pass examines the video to learn about its motion
content. The second pass performs the encode, varying the bit rate to provide better
results in scenes with motion (as compared to the one-pass VBR method). The
disadvantage of this method is that it takes twice as long as the one-pass VBR method.
Important: With the VBR methods, the basic bit rate setting determines the encoded file
size. The maximum bit rate setting does not affect the file size. Additionally, the VBR
methods are most effective when the maximum bit rate is about double the basic bit
rate, or at least 1 to 3 Mbps higher than the basic bit rate.
The integrated MPEG encoder allows you to select which of these methods you want to
use.
Choosing a Video Resolution
The resolution determines the number of pixels processed within a frame. The more pixels
used, the sharper the details in the image. Note that regardless of the resolution you
choose, most DVD players play back at full screen. The following is a list of common
resolutions used with MPEG-1 and MPEG-2 video with DVD Studio Pro.
Note: Menus must use full D1 resolution MPEG-2 video. If you assign any other resolution
or an MPEG-1 asset, the video will be transcoded to full D1 MPEG-2 when you build the
project.
SD Projects
SD projects can use the resolutions shown in the following tables.
NTSC
All frame rates use the interlaced scanning method (as indicated with an “i”). With the
exception of 352 x 240, all resolutions are MPEG-2 only.
Notes Aspect ratio Frame rate Resolution
Also known as SIF format; MPEG-1 or MPEG-2 4:3 29.97i 352 x 240
Also known as 1/2 D1 4:3 29.97i 352 x 480
Also known as Cropped D1; 16:9 is anamorphic 4:3, 16:9 29.97i 704 x 480
Also known as Full D1; 16:9 is anamorphic 4:3, 16:9 29.97i 720 x 480
63 Chapter 4 Preparing Video Assets