About this guide

The Audio Developer's Guide is intended for developers who wish to write audio applications using the QNX-extended ALSA 0.5.2 (Advanced Linux Sound Architecture, www.alsa-project.org) drivers and library.

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

To find out about:	Go to:
Writing an audio application	Playing Audio Data
Adjusting hardware-dependent values for volume and balance	Controlling Volume and Balance
Synchronizing audio and video using software	Audio Synchronization Mechanisms
Audio library functions	Audio Library
How to code a `.wav` player in C	Appendix A: `wave.c` example
Why we chose ALSA v0.50	Appendix B: Audio library and driver history
Why `libasound.a` isn't offered	Appendix C: LGPL License Agreement
Function safety and classification information	Appendix D: Summary of safety information

We assume that you've already installed Neutrino and that you're familiar with its architecture. For a detailed overview, see the Neutrino System Architecture manual.

The key components of the Neutrino Audio driver architecture include:

deva-* drivers: Audio drivers. For example, the audio driver for the Ensoniq Audio PCI cards is deva-audiopci.
libasound.so: Programmer Interface library.
<asound*.h>: Header files in /usr/include/sys/.

What's new online (as of October 17, 2000)

Changed content

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