Townshend Computer Tools DAT-Link - Bu Ering of Audio Data; Customizing the con Guration

68 Recording Tutorial
Table 6.1: Options Available for narecord
Option Typ e Default Description
narecord.AutoStart Bool No Automatically start & stop
DAT machine
narecord.SkipSilence Bo ol No Skip initial silence inter-
val at the b eginning of a
recording.
narecord.lter.resp. nn . mm String Null If non-Null, the sp eci-
cation of lter resp onse
for sample-rate converter
which converts from nn to
mm samples/second. See
Appendix 7 for details on
using this option.
narecord.lter.stopband.atten Float 90 Attenuation, in dB, of
sample-rate converters anti-
aliasing stopband.
6.13 Buering of Audio Data
Buering of audio data was describ ed in Section 5.13 with resp ect to the naplay
program. The eects of the buering are somewhat dierent when recording audio
data from the DAT-Link . Unlike playback, the internal buering has no visible
eect on recording in terms of delays or latencies.
When the host computer begins retrieving audio data from the DAT-Link , it im-
mediately b egins acquiring data from its selected digital audio input. The host
computer must then continue to read audio data from the DAT-Link suciently
quickly to keep the buer from b ecoming full. If the buer overows b efore the
host computer is nished recording, an error is returned and recording is stopp ed.
Audio data will never be lost without an error indication. The buer utilization
can be monitored by the nastatus command described in Section 10.2.
For applications where ner control over the buering is required, custom programs
can b e written using the subroutine library described in Section 12 and Appendix
G.
6.14 Customizing the Conguration
Many of the command line options, as well as additional options can be specied in
the users .datlinkrc le in their home directory. The format of this le is describ ed
in App endix B.3. The options used by narecord are listed in Table 6.1.