Pyro Industries API-1394PCI Manual de usuario descargar pdf (Pagina 67)

CHAPTER 2: CAPTURING ■

the Audio Project Settings window. Xpress Pro has more settings available than Free

DV, but everything we need for this adjustment is on both systems. Take a look at the

list of settings and click Audio Project. A menu appears with all the adjustments that

we can make to the audio settings that pertain to the current project only.

Audio Project Settings

The first order of business is to establish a sample rate for our media (see Figure 2.21). The

sample rate for DV video is normally 48 kHz. I mention that it is “normally” this rate

because if you use all four audio tracks when you shoot DV, the sample rate goes down.

Only two audio tracks are usually used when shooting DV. If you use four tracks, the

sample rate is actually 32 kHz.

At the top right of the Audio Project Settings menu is the Sample Rate data. You

can choose from among three settings: 32 kHz, 44.1 kHz, and 48 kHz. The higher the

sample rate, the better the audio quality. It is important to note that there is only mar-

ginal difference between 44.1 kHz and 48 kHz. The default sample rate for Free

DV/Xpress Pro is 48 kHz. The higher the sample rate, the more disk space is required,

but audio does not take up a significant amount of drive space, anyway.

Compact disc audio recordings normally sample at 44.1 kHz. When importing

audio or capturing from compact disc, you might need to upsample or downsample

accordingly to make that recording properly fit the audio sample rate for your project.

48 kHz is the sample rate for many digital video- and audiotape formats, including

DigiBeta. DAT can record and play back both sample rates from most players, but the

typical DAT sample rate is also 48 kHz.

So which sampling rate is best for your project? If you used four audio tracks

when recording to DV, the primary sampling rate is 32 kHz. If most or all of your

material is 32 kHz, you might consider leaving it that way rather than upsampling to

48 kHz. However, if you are going to output to several different formats—CD, DVD,

and so forth—it might be simpler to upsample everything to 48 kHz when you are fin-

ished editing the project so that the audio sounds the same on all formats. I tend to

Note: A lot of consumer DV cameras have the audio setting at 32 kHz.Consult your owner’s guide and

change this setting to 48 kHz for optimum quality.

Figure 2.21 Choosing the sample rate

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Pyro Industries API-1394PCI Manual de usuario Pagina 67