Auto-recenter head
This logic detects when the head has been approximately still for a
certain amount of time and triggers a head-recenter.
Documentation changes to follow.
Test: Integrated this code into the Spatial Audio Demo app and
manually verified.
Test: Ran the included units tests.
Change-Id: I22b9e590aa1ca725d43b78fc58ade1144f2e4e52
diff --git a/services/audiopolicy/service/SpatializerPoseController.cpp b/services/audiopolicy/service/SpatializerPoseController.cpp
index ffedf63..04b0a4a 100644
--- a/services/audiopolicy/service/SpatializerPoseController.cpp
+++ b/services/audiopolicy/service/SpatializerPoseController.cpp
@@ -45,14 +45,14 @@
// determine the time constants used for high-pass filtering those readings. If the value is set
// too high, we may experience drift. If it is set too low, we may experience poses tending toward
// identity too fast.
-constexpr auto kTranslationalDriftTimeConstant = 20s;
+constexpr auto kTranslationalDriftTimeConstant = 40s;
// This should be set to the typical time scale that the rotation sensors used drift in. This
// means, loosely, for how long we can trust the reading to be "accurate enough". This would
// determine the time constants used for high-pass filtering those readings. If the value is set
// too high, we may experience drift. If it is set too low, we may experience poses tending toward
// identity too fast.
-constexpr auto kRotationalDriftTimeConstant = 20s;
+constexpr auto kRotationalDriftTimeConstant = 40s;
// This is how far into the future we predict the head pose, using linear extrapolation based on
// twist (velocity). It should be set to a value that matches the characteristic durations of moving
@@ -64,6 +64,15 @@
// stale;
constexpr auto kMaxLostSamples = 4;
+// Auto-recenter kicks in after the head has been still for this long.
+constexpr auto kAutoRecenterWindowDuration = 10s;
+
+// Auto-recenter considers head not still if translated by this much (in meters, approx).
+constexpr float kAutoRecenterTranslationThreshold = 0.1f;
+
+// Auto-recenter considers head not still if rotated by this much (in radians, approx).
+constexpr float kAutoRecenterRotationThreshold = 5.0f / 180 * M_PI;
+
// Time units for system clock ticks. This is what the Sensor Framework timestamps represent and
// what we use for pose filtering.
using Ticks = std::chrono::nanoseconds;
@@ -85,6 +94,9 @@
.rotationalDriftTimeConstant = Ticks(kRotationalDriftTimeConstant).count(),
.freshnessTimeout = Ticks(sensorPeriod * kMaxLostSamples).count(),
.predictionDuration = Ticks(kPredictionDuration).count(),
+ .autoRecenterWindowDuration = Ticks(kAutoRecenterWindowDuration).count(),
+ .autoRecenterTranslationalThreshold = kAutoRecenterTranslationThreshold,
+ .autoRecenterRotationalThreshold = kAutoRecenterRotationThreshold,
})),
mPoseProvider(SensorPoseProvider::create("headtracker", this)),
mThread([this, maxUpdatePeriod] {