NETAUDIO(3) 183
u
float VULevelRight;
nsigned int sampleNumber; /∗ Current sample number at input or output ∗/
}
unsigned int buffered; /∗ Number of samples of buffered data ∗/
NAsnapshot;
{typedef struct
NAsnapshot pb; /∗ Playback snapshot ∗/
}
NAsnapshot rec; /∗ Record snapshot ∗/
NAsnapshots;
Snapshots can also be generated as part of NA_SNAPSHOT events. See na_event(3) for
i
details.
nt NAPause(port,playrec,pause)
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NAport ∗port;
nt playrec;
int pause;
Pause or resume transfers. playrec should be NA_PLAY or NA_RECORD to pause playback
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t
or recording respectively. The pause argument is non-zero to pause transfers, zero to resum
hem.
int NABegin(port,playrec)
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NAport ∗port;
nt playrec;
Force transfers to/from the digital audio IO’s to begin. This routine must be called before
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t
using NARead() to retrieve samples during recording. For playback, it’s use its optional sinc
ransfers to the digital audio outputs will begin automatically once the DAT-Link’s internal
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buffers are full. Also, NADrain() and NACloseData() automatically initiate playback if it has
ot already begun. Note that due to a limitation of the SCSI driver’s on most computer, the
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c
last 512 bytes of data may not be sent to the DAT-Link until NADrain() or NACloseData() i
alled. Thus, if only a small amount of data is being sent, NABegin() should NOT be called or
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the DAT-Link may underrun before the last 512 bytes can be sent.
nt NADrain(port)
NAport ∗port;
Force playback to begin if it has not already and then allow buffered samples to drain during
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a
playback. This routine will not return until all buffered data has been output to the digita
udio outputs. If all is well, NADrain() will return 0, if a server communication error occurs
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-1 will be returned, and, if a transfer error such as an underrun occurred, the transfer error code
see na_info(3) ) will be returned.
N
int NAFlush(port,playrec)
Aport ∗port;
int playrec;
Flush (delete) any buffered data for transfers in the given direction.
N
int NASetFilter(port,filter)
Aport ∗port;
;const NAfilter ∗filter
Setup the specifications for filtering during conversion of audio data by the DAT-Link. This
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structure of the filter argument is:
ypedef struct {
N
float atten;
etAudio Reference Last change: 1993/11/11 2
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