Apple Compressor (4.0) - Manual (Page 88)

Chapter 5 Custom settings and output formats 88
4 If available, use the Maximum Bit Rate slider or field to set a maximum bit rate.
Because SD DVD players support peak bit rates of up to 10.08 Mbps for video plus audio, you
should set the maximum video bit rate between 8.0 and 8.5 Mbps if you’re using a 1.5 Mbps
(two-channel AIFF) audio track.
Note: For best results, make sure the maximum bit rate is at least 1 Mbps higher than the
average setting. Larger differences can produce better results.
5 Choose one of the following settings from the Motion Estimation pop-up menu:
•
Good: The fastest motion estimation setting—sufficient when there is relatively low motion
between frames
•
Better: A good general-purpose motion estimation setting—provides very good results even in
the presence of complex interlaced motion
•
Best: The highest-quality setting to handle the most demanding and complex motion for
interlaced sources—somewhat slower than the Better mode
Stage 3: Open the GOP tab and choose GOP settings
Select a suitable GOP structure and size and decide whether you want the GOPs to be open or
closed. For more information about GOPs, see
About GOPs (groups of pictures) on page 99.
Note: These settings are not adjustable if you chose an HD video format in the Video Format tab.
1 To open the GOP tab, click the GOP button in the MPEG-2 Encoder pane of the Inspector.
Choose a GOP structure
to control how many
B-frames are used.
Choose open
or closed GOPs.
Choose a GOP size.
2 Choose a GOP structure from the GOP Structure pop-up menu.
For the majority of MPEG-2 encoding jobs for DVD authoring, choose the IBBP GOP structure.
3 Choose a GOP size from the GOP Size pop-up menu.
For the majority of MPEG-2 encoding jobs for DVD authoring, choose a GOP size of 15 for NTSC
and a GOP size of 12 for PAL and 24p.
The options available in the pop-up menu vary depending on the GOP structure you choose and
whether the GOP is open or closed.
4 Decide whether you want the GOP pattern to be open or closed, and click the appropriate button.