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Multiple Video Angles
Using multiple video angles in a track also affects the maximum allowable video bit rate
you can use. Due to the way the DVD specification requires video streams to be
multiplexed together, the number of video streams determines the maximum video bit
rate you can use in SD projects. The maximum combined bit rates (highest bit rate video
stream + all audio streams + all subtitle streams) you can use for each multi- and
mixed-angle track in an SD project is from 8.0 Mbps with two streams to 7.0 Mbps with
nine streams. See Encoding Video for Multi-Angle Tracks for more information.
HD projects using multiple video angles in a track are limited to 24.0 Mbps for the
maximum combined bit rates, regardless of the number of video angles.
Transitions
When you add a transition to a menu, to a still clip in a track, or to slides in a slideshow,
you need to account for the additional video it creates.
• In the case of menus, the transitions become short rendered video clips stored in the
same video object (VOB) file as the menus. This means that, in addition to the overall
amount of disc space menu transitions require, you must also consider their impact on
the 1 GB menu VOB file size limit. See Standard SD DVD Video Zone Files for more
information. You must also take into account that a transition video clip is rendered
for each menu button that has transitions enabled—a menu with 18 buttons can require
18 transition video clips.
• In the case of still clips in a track and slides in a slideshow, adding transitions increases
the amount of disc space each requires even if the transition does not increase the
length of the track or slideshow. This is because stills and slides use much less disc
space than the motion video created by the transitions, even if the transition is from
one slide to another.
The amount of disc space required by each transition varies depending on their length
and type. In general, for SD projects, which use a bit rate of 6 Mbps for transitions, you
should allow 750 KB of disc space for every second of transition time in the project. For
HD projects, which use a bit rate of 20 Mbps for transitions, you should allow 2.5 MB of
disc space per second.
Using the Video Bit Rate
The video bit rates you calculate can be used as the bit rate entry of your encoder,
regardless of the encoding method you intend to use (one pass, one-pass variable bit
rate [VBR], or two-pass VBR).
When using one of the VBR encoding methods in the integrated MPEG encoder, the “Bit
rate” setting affects the amount of disc space that the MPEG video file requires, while the
“Max bit rate” setting sets the highest video bit rate that is allowed in the file (but does
not affect the file size). See MPEG Encoding Methods for more information.
41Chapter 2 Planning Your Project