tree d0abca0d2c30e2279a6e631a5c25b4430b7c73e9
parent af28887c617eca259444f743ef83eda85d52d31e
author Mikhail Naganov <mnaganov@google.com> 1569445529 -0700
committer Mikhail Naganov <mnaganov@google.com> 1570229992 -0700

Add PassthruPatchRecord for low latency software patches

Implement a subclass of PatchRecord that uses PatchTrack's
thread for reading from HAL. This eliminates the need for
buffering that adds latency.

The only modification needed for PatchTrack is to indicate
unlimited amount of available frames to the playback thread.
This is to prevent PatchTrack from being deactivated by
DirectOutputThread due to lack of frames available.

RecordThread believes it reads audio data on its thread,
and manages timestamps as usual. The data that it "reads"
and passes to PassthruPatchRecord is discarded by the latter.

Bug: 117564323
Test: with MSD module
Merged-In: I376656e3c791e91e2196331ecdf2b425697c4e18
Change-Id: I376656e3c791e91e2196331ecdf2b425697c4e18