commit 879f0910c4afe773bce153f90793bfb91ec8224c
author Ytai Ben-Tsvi <ytai@google.com> Mon Sep 13 16:46:39 2021 -0700
committer Ytai Ben-Tsvi <ytai@google.com> Tue Sep 14 10:28:20 2021 -0700
tree c47ceed69ecd7ec482014fd98d2f084e95dc6ceb
parent 8b6fe3a498fe93b58cba283b710f851f5d10070e

Print timestamp lag in SensorPoseProvider-example

This is useful for assessing timestamp accuracy and latency.

Test: Invocation of the example.
Bug: 188502620
Change-Id: I685bc568ee4174157411cfe26628d0ef7b4f065a

media/libheadtracking/Android.bp

diff --git a/media/libheadtracking/Android.bp b/media/libheadtracking/Android.bp
index 015fd7e..d134ca0 100644
--- a/media/libheadtracking/Android.bp
+++ b/media/libheadtracking/Android.bp
@@ -57,6 +57,7 @@
         "libheadtracking",
         "libheadtracking-binding",
         "libsensor",
+        "libutils",
     ],
 }
 

media/libheadtracking/SensorPoseProvider-example.cpp

diff --git a/media/libheadtracking/SensorPoseProvider-example.cpp b/media/libheadtracking/SensorPoseProvider-example.cpp
index 30c6537..13db07e 100644
--- a/media/libheadtracking/SensorPoseProvider-example.cpp
+++ b/media/libheadtracking/SensorPoseProvider-example.cpp
@@ -19,9 +19,11 @@
 
 #include <android/sensor.h>
 #include <hardware/sensors.h>
+#include <utils/SystemClock.h>
 
 #include <media/SensorPoseProvider.h>
 
+using android::elapsedRealtimeNano;
 using android::media::Pose3f;
 using android::media::SensorPoseProvider;
 using android::media::Twist3f;
@@ -32,7 +34,12 @@
   public:
     void onPose(int64_t timestamp, int32_t handle, const Pose3f& pose,
                 const std::optional<Twist3f>& twist) override {
-        std::cout << "onPose t=" << timestamp << " sensor=" << handle << " pose=" << pose
+        int64_t now = elapsedRealtimeNano();
+
+        std::cout << "onPose t=" << timestamp
+                  << " lag=" << ((now - timestamp) / 1e6) << "[ms]"
+                  << " sensor=" << handle
+                  << " pose=" << pose
                   << " twist=";
         if (twist.has_value()) {
             std::cout << twist.value();