This version of this document is no longer maintained. For the latest documentation, see http://www.qnx.com/developers/docs.

About This Guide

The Audio Developer's Guide is intended for developers who wish to write audio applications using the QNX Sound Architecture (QSA) drivers and library.

This table may help you find what you need in this guide:

To find out about:	Go to:
The structure of an audio application	Audio Architecture
Playing and recording sound	Playing and Capturing Audio Data
The structure of a mixer	Mixer Architecture
Audio library functions	Audio Library
How to code a `.wav` player in C	`wave.c` example
How to code a `.wav` recorder in C	`waverec.c` example
How to code a `mix_ctl` in C	`mix_ctl.c` example
Why `libasound.a` isn't offered	LGPL License Agreement
Terms used in this guide	Glossary

You should have already installed QNX Neutrino and become familiar with its architecture. For a detailed overview, see the System Architecture guide.

The key components of the QNX Audio driver architecture include:

io-audio: Audio system manager.
deva-ctrl-*.so drivers: Audio drivers. For example, the audio driver for the Ensoniq Audio PCI cards is deva-ctrl-audiopci.so. For more information, see "Audio drivers (deva-*)" in the Utilities Summary chapter of the QNX Neutrino Utilities Reference.
libasound.so: Programmer interface library.
<asound.h>, <asoundlib.h>: Header files in /usr/include/sys/.

What's new in 6.1

Changed content

snd_pcm_channel_info(): Removed the SND_PCM_CHNINFO_BATCH flag because it was deprecated in the source code.

What's new in 6.2

The QNX Sound Architecture has evolved away from ALSA. You should reread this entire guide.

What's new in 6.3

Three function calls, a structure, and a <mix_ctl.c> example were added: