\section{\module{sunaudiodev} ---         Access to Sun audio hardware} \declaremodule{builtin}{sunaudiodev}  \platform{SunOS}\modulesynopsis{Access to Sun audio hardware.}  This module allows you to access the Sun audio interface. The Sunaudio hardware is capable of recording and playing back audio datain u-LAW\index{u-LAW} format with a sample rate of 8K per second. Afull description can be found in the \manpage{audio}{7I} manual page. The module\refmodule[sunaudiodev-constants]{SUNAUDIODEV}\refstmodindex{SUNAUDIODEV} defines constants which may be used with this module. This module defines the following variables and functions: \begin{excdesc}{error}This exception is raised on all errors. The argument is a stringdescribing what went wrong.\end{excdesc} \begin{funcdesc}{open}{mode}This function opens the audio device and returns a Sun audio deviceobject. This object can then be used to do I/O on. The \var{mode} parameteris one of \code{'r'} for record-only access, \code{'w'} for play-onlyaccess, \code{'rw'} for both and \code{'control'} for access to thecontrol device. Since only one process is allowed to have the recorderor player open at the same time it is a good idea to open the deviceonly for the activity needed. See \manpage{audio}{7I} for details. As per the manpage, this module first looks in the environmentvariable \code{AUDIODEV} for the base audio device filename.  If notfound, it falls back to \file{/dev/audio}.  The control device iscalculated by appending ``ctl'' to the base audio device.\end{funcdesc}  \subsection{Audio Device Objects \label{audio-device-objects}} The audio device objects are returned by \function{open()} define thefollowing methods (except \code{control} objects which only provide\method{getinfo()}, \method{setinfo()}, \method{fileno()}, and\method{drain()}): \begin{methoddesc}[audio device]{close}{}This method explicitly closes the device. It is useful in situationswhere deleting the object does not immediately close it since thereare other references to it. A closed device should not be used again.\end{methoddesc} \begin{methoddesc}[audio device]{fileno}{}Returns the file descriptor associated with the device.  This can beused to set up \code{SIGPOLL} notification, as described below.\end{methoddesc} \begin{methoddesc}[audio device]{drain}{}This method waits until all pending output is processed and then returns.Calling this method is often not necessary: destroying the object willautomatically close the audio device and this will do an implicit drain.\end{methoddesc} \begin{methoddesc}[audio device]{flush}{}This method discards all pending output. It can be used avoid theslow response to a user's stop request (due to buffering of up to onesecond of sound).\end{methoddesc} \begin{methoddesc}[audio device]{getinfo}{}This method retrieves status information like input and output volume,etc. and returns it in the form ofan audio status object. This object has no methods but it contains anumber of attributes describing the current device status. The namesand meanings of the attributes are described in\code{<sun/audioio.h>} and in the \manpage{audio}{7I}manual page.  Member namesare slightly different from their C counterparts: a status object isonly a single structure. Members of the \cdata{play} substructure have\samp{o_} prepended to their name and members of the \cdata{record}structure have \samp{i_}. So, the C member \cdata{play.sample_rate} isaccessed as \member{o_sample_rate}, \cdata{record.gain} as \member{i_gain}and \cdata{monitor_gain} plainly as \member{monitor_gain}.\end{methoddesc} \begin{methoddesc}[audio device]{ibufcount}{}This method returns the number of samples that are buffered on therecording side, i.e.\ the program will not block on a\function{read()} call of so many samples.\end{methoddesc} \begin{methoddesc}[audio device]{obufcount}{}This method returns the number of samples buffered on the playbackside. Unfortunately, this number cannot be used to determine a numberof samples that can be written without blocking since the kerneloutput queue length seems to be variable.\end{methoddesc} \begin{methoddesc}[audio device]{read}{size}This method reads \var{size} samples from the audio input and returnsthem as a Python string. The function blocks until enough data is available.\end{methoddesc} \begin{methoddesc}[audio device]{setinfo}{status}This method sets the audio device status parameters. The \var{status}parameter is an device status object as returned by \function{getinfo()} andpossibly modified by the program.\end{methoddesc} \begin{methoddesc}[audio device]{write}{samples}Write is passed a Python string containing audio samples to be played.If there is enough buffer space free it will immediately return,otherwise it will block.\end{methoddesc} The audio device supports asynchronous notification of various events,through the SIGPOLL signal.  Here's an example of how you might enablethis in Python: \begin{verbatim}def handle_sigpoll(signum, frame):    print 'I got a SIGPOLL update' import fcntl, signal, STROPTS signal.signal(signal.SIGPOLL, handle_sigpoll)fcntl.ioctl(audio_obj.fileno(), STROPTS.I_SETSIG, STROPTS.S_MSG)\end{verbatim}  \section{\module{SUNAUDIODEV} ---         Constants used with \module{sunaudiodev}} \declaremodule[sunaudiodev-constants]{standard}{SUNAUDIODEV}  \platform{SunOS}\modulesynopsis{Constants for use with \refmodule{sunaudiodev}.}  This is a companion module to\refmodule{sunaudiodev}\refbimodindex{sunaudiodev} which definesuseful symbolic constants like \constant{MIN_GAIN},\constant{MAX_GAIN}, \constant{SPEAKER}, etc. The names of theconstants are the same names as used in the C include file\code{<sun/audioio.h>}, with the leading string \samp{AUDIO_}stripped.