17.1.1. Audio Device Objects

close () -- Method on audio device

This method explicitly closes the device. It is useful in situations where deleting the object does not immediately close it since there are other references to it. A closed device should not be used again.

drain () -- Method on audio device

This method waits until all pending output is processed and then returns. Calling this method is often not necessary: destroying the object will automatically close the audio device and this will do an implicit drain.

flush () -- Method on audio device

This method discards all pending output. It can be used avoid the slow response to a user's stop request (due to buffering of up to one second of sound).

getinfo () -- Method on audio device

This method retrieves status information like input and output volume, etc. and returns it in the form of an audio status object. This object has no methods but it contains a number of attributes describing the current device status. The names and meanings of the attributes are described in /usr/include/sun/audioio.h and in the audio man page. Member names are slightly different from their C counterparts: a status object is only a single structure. Members of the play substructure have `o_' prepended to their name and members of the record structure have `i_'. So, the C member play.sample_rate is accessed as o_sample_rate, record.gain as i_gain and monitor_gain plainly as monitor_gain.

ibufcount () -- Method on audio device

This method returns the number of samples that are buffered on the recording side, i.e. the program will not block on a read call of so many samples.

obufcount () -- Method on audio device

This method returns the number of samples buffered on the playback side. Unfortunately, this number cannot be used to determine a number of samples that can be written without blocking since the kernel output queue length seems to be variable.

read (size) -- Method on audio device

This method reads size samples from the audio input and returns them as a python string. The function blocks until enough data is available.

setinfo (status) -- Method on audio device

This method sets the audio device status parameters. The status parameter is an device status object as returned by getinfo and possibly modified by the program.

write (samples) -- Method on audio device

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.

Useability of the control device is limited at the moment, since there is no way to use the ``wait for something to happen'' feature the device provides.