File Sampling Rate; File Formats - Townshend Computer Tools DAT-Link User Manual

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5.7.2 File Sampling Rate

If the le stored on the computer is not at the same sampling rate as that which
will be used by the DAT machine, a sampling-rate conversion operation must be
performed. This is done automatically in real time by the
built-in digital signal processor. To invoke a conversion, you need only specify
the sampling rate of the le using the
a mono le of speech stored on disk that was sampled at 8,000 samples/second.
Further, assume you wish to record this le onto both channels of a DAT at 44,100
samples/second. The appropriate command would be:
naplay -omono -s 8000 -S 44100 file
The option selects monophonic playback, the
-omono
sampled at 8,000 samples/second and the
generate audio data at 44,100 samples/second. To perform this command the
Link
will perform a digital resampling operation which will result in some low-pass
ltering of the audio signal. See Chapter 7 for more information on the e ects of
this conversion.

5.8 File Formats

In the above sections we have assumed the le being used contains just audio data
stored as 16 bit signed integers. By default
type by using various heuristics. If these fail, a warning message will be printed and
the format will be used. Other formats are available by using the
raw
followed by a format name. A full list of possible formats can be displayed by
typing:
naplay -f help
Appendix B.1 describes the encoding of each format.
In addition, to the overall le format, the type of data encoding can be speci ed
using the option. The valid encoding choices are:
-e
:
Direct linear encoding of the data as signed integers. The precision of the
Linear
values defaults to 16 bits/sample, but can be changed using the
described below. This is the default encoding.
:
IEEE oating point format using 4 bytes/sample.
IEEE
:
One byte per sample, A-law companded data.
ALaw
:
One byte per sample, mu-law companded data.
uLaw
Playback Tutorial
DAT-Link
option. As an example, assume you have
-s
-s 8000
instructs the
-S 44100
will attempt to deduce the le
naplay
using its
means the le is
DAT-Link
to
DAT-
option
-f
option
-p