Ulead 1.0 - Manual (Page 87)

SpruceUp User’s Guide 4—15
Audio Assets
SpruceUp requires the audio assets to be associated with the video assets, either as an
elementary file with the same name and in the same directory as the video file but with a
different extension, or as part of a multiplexed (also referred to as system or program)
MPEG file. The audio is treated as being inseparable from the video; it cannot be trimmed or
in any other way handled independently of the video.
Compressed vs. Uncompressed
The supported audio formats include some with compression and some without.
Compressed formats, including MPEG-1 Layer 2 and Dolby Digital's AC-3, have the
advantage of being much smaller files, yet still having very good quality. Typically used bit-
rates vary from 192kbps to 448kbps. The MP3 format, while part of the MPEG family, is not
supported by the DVD specification.
Uncompressed formats, such as PCM, WAV, and AIFF, have excellent quality, but with large
file sizes. These are often generically referred to as PCM files – similar to what is used on
audio CDs. The DVD specification requires WAV, PCM, and AIFF audio to be 16, 20, or 24
bits sampled at a 48Khz (1,536kbps for two channels) or 96Khz rate (as opposed to the
more common CD rate of 44.1Khz).
Important: SpruceUp supports 16 bits at 48Khz only.
See the Disc Space Math topic for details on how the above values were arrived at.
Choosing a format may in large part depend on the media the title will be distributed on.
Dolby® Digital AC-3
Dolby Digital audio, commonly referred to as AC-3, is a compressed format suitable for DVD
titles. It can be from a single channel up to six, supporting 5.1 surround sound. In other
words, not all AC-3 audio is 5.1 – most often it is a simple 2-channel arrangement.
The WinDVD player included with SpruceUp supports playing Dolby Digital audio, however
Dolby requires a licensing fee for each player. For this reason, the WinDVD player on trial
versions of SpruceUp cannot play AC-3 audio – you must upgrade to the full version (or
register your full version if you have not already done so). Playing back AC-3 audio, either
with the Simulate mode or by using the Clip Properties dialog, results in a muted output.
The Syzygy DVD player that can be freely exported along with your titles is not able to play
AC-3 files for the same licensing reasons.