I have read that audio latency has been reduced to as low as 12ms on the Android 4.2 Jelly Bean OS. However, I have also read that this improvement is available on the Nexus 10 but not on the Nexus 7.
How could these two devices use the same OS and yet have different audio latency? Is this information accurate?
The concrete implementation of AudioHardwareInterface
is an implementation decision for a phone vendor- in many cases it's built on alsa
, but doesn't have to be.
Below this level there is a great deal of choice of the SoC platform used (nVidia Tegra3 in Nexus 7 and Samsung Exynos in Nexus 10). The OS is very definitely not the same below this level.
Factors that potentially affect latency include:
mlock
the program code and stack in memory. If you can't get this (and I suspect you still can't on Android), the value of latency is chosen such that audio runs reliably most of the time.