Approaches for constant audio latency on Android

Rudi Villing; Victor Lazzarini; Joseph Timoney; Dawid Czesak; Sean O'Leary
DAFx-2015 - Trondheim
This paper discusses issues related to audio latency for realtime processing Android OS applications. We first introduce the problem, determining the difference between the concepts of low latency and constant latency. It is a well-known issue that programs written for this platform cannot implement low-latency audio. However, in some cases, while low latency is desirable, it is not crucial. In some of these cases, achieving a constant delay between control events and sound output is the necessary condition. The paper briefly outlines the audio architecture in the Android platform to tease out the difficulties. Following this, we proposed some approaches to deal with two basic situations, one where the audio callback system provided by the system software is isochronous, and one where it is not.