exynos: libaudio: Allow overriding low latency capture duration

Change-Id: Id93ec9c4b4192cea598b71b2ddfb83e78a5be7c0
diff --git a/include/libaudio/audiohal/audio_definition.h b/include/libaudio/audiohal/audio_definition.h
index a90e9cc..bc27918 100644
--- a/include/libaudio/audiohal/audio_definition.h
+++ b/include/libaudio/audiohal/audio_definition.h
@@ -29,7 +29,9 @@
 
 // Duration for Normal Capture
 #define PREDEFINED_MEDIA_CAPTURE_DURATION   20  // 20ms
+#ifndef PREDEFINED_LOW_CAPTURE_DURATION
 #define PREDEFINED_LOW_CAPTURE_DURATION     4   // 4ms
+#endif
 
 // Duration for USB Playback and Capture
 #ifndef PREDEFINED_USB_PLAYBACK_DURATION
diff --git a/libaudio/audiohal/Android.mk b/libaudio/audiohal/Android.mk
index c48da07..8b04718 100644
--- a/libaudio/audiohal/Android.mk
+++ b/libaudio/audiohal/Android.mk
@@ -53,6 +53,10 @@
 LOCAL_CFLAGS += -DSUPPORT_STHAL_INTERFACE
 endif
 
+ifneq ($(BOARD_LOW_LATENCY_CAPTURE_DURATION),)
+LOCAL_CFLAGS += -DPREDEFINED_LOW_CAPTURE_DURATION=$(BOARD_LOW_LATENCY_CAPTURE_DURATION)
+endif
+
 LOCAL_MODULE := audio.primary.$(TARGET_SOC)
 LOCAL_PROPRIETARY_MODULE := true
 LOCAL_MODULE_RELATIVE_PATH := hw