• 07/14/2017
  • Public Content
Contents

Audio Framework

Overview
The Ref-OS-IoT uses the Advanced Linux Sound Architecture (ALSA) framework to deliver Audio features to application.
Audio Software Stack
Audio Software Architecture shown below outlines the OS audio Stack which covers the following aspects:
  • Application uses GStreamer to setup the Audio pipeline.
  • GStreamer provides ALSA sink and source used on the pipeline
  • GStreamer good and bad audio codecs are used as filters in the audio pipeline.
  • ALSA library provides a transparent access to audio driver to play and record audio
 
Pulse Audio Features
PulseAudio is a networked sound server for advanced audio features such as:
  • Software mixing of multiple audio streams, bypassing any restrictions the hardware has.
  • Sample rate conversion of audio streams
  • Network transparency, allowing an application to play back or record audio on a different machine than the one it is running on.
  • Sound API abstraction, alleviating the need for multiple back-ends in applications to handle the wide diversity of sound systems out there.
  • Generic hardware abstraction, giving the possibility of doing things like individual volumes per application.
  • PulseAudio comes with many plugin modules.
GStreamer
Hardware Codec Connection
The Intel® Joule™ developer kit does not include a hardware audio codec. A reference connection is provided in Audio Interface topic in the Expansion Board Design Guide section.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804