User manual

419
Export Audio Mixdown
The following options are available:
General tab
In the Input Stream section, you set the sample rate (44.1,
48 or 96 kHz) and the bit resolution (16 bit or 24 bit) of the
encoded file. These should be set to match the sample rate
and bit resolution of the source material. If no value matches
that of your source material, use the closest available value
that is higher than the actual value. E.g. if you’re using 20 bit
source material, set the bit resolution to 24 bit rather than
16 bit.
Ö The setting in the Channels field depends on the cho-
sen output and cannot be changed manually.
The settings in the Encoding Scheme section are used for
defining the desired output from the encoder, e.g. whether
it should be a stereo file or a 5.1 surround file. Make set-
tings appropriate for the intended use of the file. If the file
will be downloaded or streamed on the Internet, you might
not want too high bit rates, for example. See below for de-
scriptions of the options.
• Mode
The WMA Pro encoder can use either a constant bit rate
or a variable bit rate for encoding to 5.1 surround, or it can
use lossless encoding for encoding to stereo. The options
on this menu are as follows:
• Bit Rate/Quality
This menu allows you to set the desired bit rate. The avail-
able bit rate settings vary depending on the selected
mode and/or output channels (see above). If the Mode
“Variable Bitrate” is used (see above), the menu allows
you to select from various levels of desired quality, with 10
being the lowest and 100 the highest. Generally, the
higher the bitrate or quality you select, the larger the final
file will be. The menu also shows the channel format (5.1
or stereo).
Advanced tab
• Dynamic Range Control
These controls allow you to define the dynamic range of
the encoded file. The dynamic range is the difference in
dB between the average loudness and the peak audio
level (the loudest sounds) of the audio. These settings af-
fect how the audio is reproduced if the file is played on a
Windows XP computer with a player from the Windows
Media series, and the user activates the special “Quiet
Mode” feature of the player to control the dynamic range.
The dynamic range is automatically calculated during the
encoding process, but you can specify it manually as well.
If you want to manually specify the dynamic range, first put
a checkmark in the box to the left by clicking in it, and then
enter the desired dB values in the Peak and Average
fields. You can enter any value between 0 and -90dB.
Note, however, that it is usually not recommended to
change the Average value, since it affects the overall vol-
ume level of the audio and therefore can affect the audio
quality adversely.
The Quiet Mode in a Windows Media player can be set to
one of three settings. Below, these settings are listed to-
gether with an explanation of how the Dynamic Range set-
tings affect them:
• Off: If Quiet Mode is off, the dynamic range settings that were
automatically calculated during the encoding will be used.
• Little Difference: If this is selected and you have not manually
changed the dynamic range settings, the peak level will be
limited to 6dB above the average level during playback. If you
have manually specified the dynamic range, the peak level will
be limited to the mean value between the peak and average
values you specified.
• Medium Difference: If this is selected and you have not manu-
ally changed the dynamic range settings, the peak level will be
limited to 12dB above the average level. If you have changed
the dynamic range, the peak level will be limited to the peak
value you specified.
Mode Description
Constant Bitrate This will encode to a 5.1 surround file with a constant
bit rate (set in the Bit Rate/Channels menu, see be-
low). Constant bit rate is preferably used if you want to
limit the size of the final file. The size of a file encoded
with a constant bit rate is always the bit rate times the
duration of the file.
Variable Bitrate Encodes to a 5.1 surround file with a variable bit rate,
according to a quality scale (the desired quality is set
in the Bit Rate/Channels menu, see below). When you
encode with variable bit rates, the bit rate fluctuates
depending on the character and intricacy of the mate-
rial being encoded. The more complex passages in the
source material, the higher the bit rate – and the larger
the final file.
Lossless Encodes to a stereo file with lossless compression.