audio HAL: add audio pre processing.

Added support for audio pre processing and echo reference
for AEC.

Also:
- added defines for ABE ports sampling rates
- always select sub mic for camcorder and VoIP on speakerphone
even if headset with mic is present
- change mutex locking order: first hw device then stream.
This allows calling functions on active output and input streams
without releasing the hw device mutex.
Aquiring the hw device mutex systematically in dtream read and write
guarantees that a low priority thread waiting on the stream mutex will
get it in a timely manner.

Change-Id: I4abc9e56b30e7b72109db1961af76c6fd4c03be0

0 files changed, 0 insertions, 0 deletions