ALopenport(3dm)ALopenport(3dm)NAMEALopenport - (obsolete) open an audio port
SYNOPSIS
#include <dmedia/audio.h>
ALport ALopenport(char *name, char *direction, ALconfig config)
PARAMETER
name A port name is an ASCII string which summarizes the usage of
this port. It is intended for human consumption, similar to
a window title. Port names have a maximum length of 20
characters.
direction Use this parameter to identify whether the port is an input
or an output port. Acceptable values are:
"r" configures the port for reading (input).
"w" configures the port for writing (output).
config Expects the ALconfig structure returned by ALnewconfig(3dm).
This structure contains information that ALopenport(3dm) uses
to configure the port.
Passing a null (0) structure for this parameter, yields a
port with the default configuration.
DESCRIPTIONALopenport is obsolete and is provided for backward compatibility. The
preferred function is alOpenPort(3dm).
ALopenport(3dm) allocates and initializes an ALport structure, creating a
programmatic connection to the audio system. You can open more than one
port at a time, up to a limit imposed by the particular hardware
configuration.
The default port has a 100,000 sample stereo buffer, utilizing a 16-bit
two's complement sample format.
Upon opening, an input port immediately begins to fill with samples. You
should remove samples from the port post haste, lest the sample queue
overflow. Upon opening, an output port will attempt to remove samples
from the sample queue. You should provide samples to the port with great
alacrity or the sample queue will underflow.
ALopenport can fail for the following reasons:
AL_BAD_CONFIG config is invalid.
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ALopenport(3dm)ALopenport(3dm)
AL_BAD_DIRECTION direction is not valid.
AL_BAD_OUT_OF_MEM insufficient memory is available to allocate the
ALport structure.
AL_BAD_DEVICE_ACCESS audio hardware is inaccessible.
AL_BAD_NO_PORTS no audio ports are currently available.
DIAGNOSTICS
If successful, ALopenport(3dm) returns an ALport structure for the named
port. Otherwise, ALopenport(3dm) returns a null (0) valued structure and
sets an error number; this error can be retrieved with oserror(3C).
SEE ALSOALcloseport(3dm), ALnewconfig(3dm), ALsetconfig(3dm), ALqueryparams(3dm),
oserror(3C)
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