fixed issue with step counter

app/src/androidTest/java/com/example/jnicpp/bowling/VideoStepReplayTest.kt

@@ -0,0 +1,78 @@
+package com.example.jnicpp.bowling
+
+import android.media.MediaMetadataRetriever
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import com.google.android.gms.tasks.Tasks
+import com.google.mlkit.vision.common.InputImage
+import com.google.mlkit.vision.pose.PoseDetection
+import com.google.mlkit.vision.pose.accurate.AccuratePoseDetectorOptions
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * Replays a pre-recorded reference video through the exact same
+ * detection/smoothing/step-counting pipeline the live camera screen uses
+ * (PoseAnalyzer's detector config -> PoseLandmarkSmoother ->
+ * AnkleHipMovingAverageFilter -> buildPoseFrame -> LiveStepDetector), so the
+ * algorithm can be validated against a video with a known, hand-counted
+ * step count without needing a live device recording session each time.
+ *
+ * Not run as part of the normal test suite -- this is a diagnostic tool,
+ * invoked directly via `connectedAndroidTest` with a specific video pushed
+ * to the device first.
+ */
+@RunWith(AndroidJUnit4::class)
+class VideoStepReplayTest {
+
+    @Test
+    fun replayReferenceVideo() {
+        val context = InstrumentationRegistry.getInstrumentation().targetContext
+        val videoPath = context.getExternalFilesDir(null)!!.resolve("reference_test.mp4").absolutePath
+
+        val retriever = MediaMetadataRetriever()
+        retriever.setDataSource(videoPath)
+        val durationMs = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)
+            ?.toLongOrNull() ?: 0L
+
+        val detector = PoseDetection.getClient(
+            AccuratePoseDetectorOptions.Builder()
+                .setDetectorMode(AccuratePoseDetectorOptions.STREAM_MODE)
+                .build()
+        )
+        val landmarkSmoother = PoseLandmarkSmoother()
+        val ankleHipSmoother = AnkleHipMovingAverageFilter()
+        val liveStepDetector = LiveStepDetector()
+        val logger = DebugSessionLogger(context)
+        logger.start()
+
+        val stepMs = 33L
+        var t = 0L
+        var finalStepCount = 0
+        var framesProcessed = 0
+        while (t < durationMs) {
+            val bitmap = retriever.getFrameAtTime(t * 1000, MediaMetadataRetriever.OPTION_CLOSEST)
+            if (bitmap != null) {
+                val inputImage = InputImage.fromBitmap(bitmap, 0)
+                val pose = Tasks.await(detector.process(inputImage))
+                val landmarks = landmarkSmoother.smooth(pose)
+                val angles = PoseAngleCalculator.compute(landmarks)
+                val smoothedAnkleHip = ankleHipSmoother.smooth(landmarks)
+                val frame = buildPoseFrame(t, landmarks, smoothedAnkleHip, angles)
+                val result = liveStepDetector.update(frame)
+                finalStepCount = result.stepCount
+                logger.log(landmarks, t, finalStepCount)
+                framesProcessed++
+            }
+            t += stepMs
+        }
+        logger.stop()
+        detector.close()
+        retriever.release()
+
+        println(
+            "VideoStepReplayTest: processed $framesProcessed frames over ${durationMs}ms, " +
+                "final step count = $finalStepCount"
+        )
+    }
+}

app/src/main/java/com/example/jnicpp/bowling/LiveStepDetector.kt

@@ -58,12 +58,16 @@ import kotlin.math.sqrt
  *
  * @param minSpacingMs Minimum time, in milliseconds, between two accepted peaks for the same foot.
  * @param minProminenceRatio Minimum required peak prominence, as a fraction of torso scale.
+ * @param maxFrameJumpRatio Maximum single-frame ankle-y movement, as a
+ *        fraction of torso scale, still trusted as real motion rather than
+ *        a detection glitch -- see the outlier gate in [update].
  * @param stillnessWindowMs How long, in milliseconds, hip position must stay put to count as a held stance.
  * @param stillnessRatio Maximum hip position drift, as a fraction of torso scale, still considered "still".
  */
 class LiveStepDetector(
     private val minSpacingMs: Long = 300L,
     private val minProminenceRatio: Float = 0.15f,
+    private val maxFrameJumpRatio: Float = 0.25f,
     private val stillnessWindowMs: Long = 600L,
     private val stillnessRatio: Float = 0.05f
 ) {
@@ -102,6 +106,15 @@ class LiveStepDetector(
     private var lastRightAnkleRaw: LandmarkPoint? = null
     private var lastHipMid: Pair<Float, Float>? = null
 
+    // Last raw ankle-y actually fed to the peak trackers, per foot --
+    // distinct from lastLeftAnkleRaw/lastRightAnkleRaw above, which record
+    // *every* frame's reading (glitched or not) so the stall check keeps
+    // working. These only advance past a sample that clears the outlier
+    // gate in [update], so one glitched frame can't drag the reference
+    // point away from real motion and mask the next frame's genuine jump.
+    private var lastGoodLeftAnkleY: Float? = null
+    private var lastGoodRightAnkleY: Float? = null
+
     /**
      * @brief Feeds one frame's pose data into the detector, updating step
      *        count/stillness state and returning what happened this call.
@@ -147,16 +160,35 @@ class LiveStepDetector(
         // busy) risks flattening the peak we're trying to detect into
         // nothing. The heavier smoothing is still right for PoseFrame's
         // stored/displayed values -- just not for finding the peak itself.
+        //
+        // Each reading is first checked against isPlausibleJump: confirmed
+        // against a real device trace where torso scale was small (~45-79px,
+        // a distant/small subject) and single-frame ankle-y jumps of
+        // 15-88px showed up dozens of times -- physically implausible
+        // movement in a single ~30-60ms analysis frame at that scale (the
+        // same trace's genuine footfalls only ever moved ~10-12px total
+        // across several frames). Those jumps are momentary landmark
+        // detection glitches, not real motion, and fed the live counter to
+        // 27 "steps" in 24 seconds. A glitched sample is skipped entirely
+        // rather than reset anything -- lastGoodLeftAnkleY/lastGoodRightAnkleY
+        // only advance past a trusted reading, so the next frame is still
+        // compared against real motion instead of the glitch.
         frame.leftAnkleRaw?.let { ankle ->
-            leftFoot.update(frame.timestampMs, ankle.y, scale)?.let { confirmedAtMs ->
-                stepCount++
-                newSteps.add(StepEvent(confirmedAtMs, Foot.LEFT, stepCount))
+            if (isPlausibleJump(lastGoodLeftAnkleY, ankle.y, scale)) {
+                lastGoodLeftAnkleY = ankle.y
+                leftFoot.update(frame.timestampMs, ankle.y, scale)?.let { confirmedAtMs ->
+                    stepCount++
+                    newSteps.add(StepEvent(confirmedAtMs, Foot.LEFT, stepCount))
+                }
             }
         }
         frame.rightAnkleRaw?.let { ankle ->
-            rightFoot.update(frame.timestampMs, ankle.y, scale)?.let { confirmedAtMs ->
-                stepCount++
-                newSteps.add(StepEvent(confirmedAtMs, Foot.RIGHT, stepCount))
+            if (isPlausibleJump(lastGoodRightAnkleY, ankle.y, scale)) {
+                lastGoodRightAnkleY = ankle.y
+                rightFoot.update(frame.timestampMs, ankle.y, scale)?.let { confirmedAtMs ->
+                    stepCount++
+                    newSteps.add(StepEvent(confirmedAtMs, Foot.RIGHT, stepCount))
+                }
             }
         }
 
@@ -194,6 +226,25 @@ class LiveStepDetector(
         lastLeftAnkleRaw = null
         lastRightAnkleRaw = null
         lastHipMid = null
+        lastGoodLeftAnkleY = null
+        lastGoodRightAnkleY = null
+    }
+
+    /**
+     * @brief Whether a new ankle-y reading is plausible real motion given
+     *        the last trusted reading for that same foot, rather than a
+     *        one-frame detection glitch.
+     * @param lastGoodY The last reading that itself passed this check, or
+     *        null if none yet established (nothing to compare against).
+     * @param newY This frame's raw ankle-y reading.
+     * @param scale Current best-known torso length in pixels, or null if
+     *        none established yet (nothing to scale the check by).
+     * @return true if there's no reference to compare against yet, or the
+     *         movement is within [maxFrameJumpRatio] of torso scale.
+     */
+    private fun isPlausibleJump(lastGoodY: Float?, newY: Float, scale: Float?): Boolean {
+        if (lastGoodY == null || scale == null || scale <= 0f) return true
+        return kotlin.math.abs(newY - lastGoodY) <= scale * maxFrameJumpRatio
     }
 
     /**
@@ -259,6 +310,14 @@ private enum class TrackingMode { SEEKING_PEAK, SEEKING_VALLEY }
  * about it looks like a drop until the foot actually lifts again) while
  * still rejecting pure jitter that never clears the threshold either way.
  *
+ * Single-frame detection glitches (a momentary implausible ankle-y jump)
+ * are filtered out *before* they ever reach this tracker -- see the
+ * isPlausibleJump gate in [LiveStepDetector.update] -- rather than handled
+ * here, since a real footfall's prominence (confirmed against a real
+ * device trace: as little as ~10-12px at that recording's torso scale) can
+ * be smaller than a single glitched frame's jump, so no prominence
+ * threshold on its own can tell the two apart.
+ *
  * @param minSpacingMs Minimum time, in milliseconds, between two accepted peaks.
  * @param minProminenceRatio Minimum required peak prominence, as a fraction of torso scale.
  */

app/src/test/java/com/example/jnicpp/bowling/LiveStepDetectorTest.kt

@@ -42,14 +42,21 @@ class LiveStepDetectorTest {
         val detector = LiveStepDetector()
 
         // Left-foot step: rising, peak, falling -- confirms on the 3rd call.
+        // Amplitude (60px) is comfortably above the 45px prominence
+        // threshold at this torsoScale (~300) but stays under the outlier
+        // gate's 75px single-frame cutoff (maxFrameJumpRatio 0.25 * 300),
+        // since these three frames are a simplified stand-in for what a
+        // real footfall spreads across several -- see
+        // gradualPeakOnAPlateauIsDetected for the shape that actually
+        // reaches the detector in production.
         detector.update(frame(0, ankleL = 1000f, ankleR = 700f, hipX = 400f, hipY = 800f))
-        detector.update(frame(50, ankleL = 1100f, ankleR = 700f, hipX = 402f, hipY = 802f))
+        detector.update(frame(50, ankleL = 1060f, ankleR = 700f, hipX = 402f, hipY = 802f))
         var result = detector.update(frame(100, ankleL = 1000f, ankleR = 700f, hipX = 405f, hipY = 805f))
         assertEquals(1, result.stepCount)
 
         // Right-foot step, past the 300ms refractory window.
         detector.update(frame(350, ankleL = 1000f, ankleR = 700f, hipX = 410f, hipY = 810f))
-        detector.update(frame(400, ankleL = 1000f, ankleR = 800f, hipX = 415f, hipY = 815f))
+        detector.update(frame(400, ankleL = 1000f, ankleR = 760f, hipX = 415f, hipY = 815f))
         result = detector.update(frame(450, ankleL = 1000f, ankleR = 700f, hipX = 420f, hipY = 820f))
         assertEquals(2, result.stepCount)
 
@@ -73,8 +80,9 @@ class LiveStepDetectorTest {
     fun genuineStillnessStillResets() {
         val detector = LiveStepDetector()
 
+        // Amplitude 60px -- see the comment in stalledFramesDoNotResetAnInProgressCount.
         detector.update(frame(0, ankleL = 1000f, ankleR = 700f, hipX = 400f, hipY = 800f))
-        detector.update(frame(50, ankleL = 1100f, ankleR = 700f, hipX = 402f, hipY = 802f))
+        detector.update(frame(50, ankleL = 1060f, ankleR = 700f, hipX = 402f, hipY = 802f))
         val afterStep = detector.update(frame(100, ankleL = 1000f, ankleR = 700f, hipX = 405f, hipY = 805f))
         assertEquals(1, afterStep.stepCount)
 
@@ -161,4 +169,80 @@ class LiveStepDetectorTest {
 
         assertEquals(0, result.stepCount)
     }
+
+    /**
+     * Reproduces the over-counting bug found on a real device trace where
+     * the bowler's torso scale was ~45-79px (small/distant subject in
+     * frame) rather than the ~300px used elsewhere in this file: single-frame
+     * ankle-y jumps of 15-88px showed up dozens of times in that trace --
+     * physically implausible movement in one ~30-60ms frame at that scale
+     * -- and each got read as its own step, running the live counter to 27
+     * "steps" in 24 seconds of a recording with 5 real steps. A prominence
+     * floor can't fix this: that same recording's genuine footfalls had as
+     * little as ~10-12px of prominence, smaller than the glitch jumps
+     * themselves, so no fixed threshold can separate the two by amplitude
+     * alone -- confirmed separately by replaying both a floored and an
+     * unfloored threshold against a clean reference recording with a known
+     * step count, where flooring high enough to reject the glitch jumps
+     * also rejected 4 of the 5 real steps. The actual fix instead rejects
+     * any one frame whose ankle-y moved further than maxFrameJumpRatio *
+     * torsoScale since the last *trusted* reading, before it ever reaches
+     * the peak tracker.
+     */
+    @Test
+    fun implausibleSingleFrameJumpNeverConfirms() {
+        val detector = LiveStepDetector()
+        // shoulder is fixed at (400,500) -- see frame() -- so hipY=455
+        // gives a shoulder-to-hip distance of 45, matching the real trace's
+        // median torsoScale. maxFrameJumpRatio defaults to 0.25, so
+        // anything over 11.25px in one frame from the last trusted reading
+        // gets rejected outright.
+        val hipY = 455f
+
+        var result = LiveStepDetector.Result(0, emptyList(), false)
+        var t = 0L
+        // Establish a trusted baseline.
+        result = detector.update(frame(t, ankleL = 400f, ankleR = 700f, hipX = 400f, hipY = hipY))
+        t += 30L
+        result = detector.update(frame(t, ankleL = 402f, ankleR = 700f, hipX = 400f, hipY = hipY))
+        t += 30L
+
+        // A single implausible spike -- 80px in one frame -- then straight
+        // back. Before the outlier gate, this pair alone was enough to
+        // read as a confirmed peak: the spike became the running high, and
+        // the drop right back down cleared the (much smaller) ratio-only
+        // prominence threshold at this torso scale.
+        result = detector.update(frame(t, ankleL = 482f, ankleR = 700f, hipX = 400f, hipY = hipY))
+        t += 30L
+        result = detector.update(frame(t, ankleL = 403f, ankleR = 700f, hipX = 400f, hipY = hipY))
+        t += 30L
+
+        assertEquals("an implausible single-frame jump should never read as a step", 0, result.stepCount)
+    }
+
+    /**
+     * Control case for the same fix: genuine motion at the same small
+     * torso scale, arriving gradually (each frame's move well within
+     * maxFrameJumpRatio) rather than as one implausible jump, should still
+     * confirm -- the outlier gate isn't just disabling small-scale
+     * detection outright.
+     */
+    @Test
+    fun gradualMotionAtSmallTorsoScaleStillConfirms() {
+        val detector = LiveStepDetector()
+        val hipY = 455f // torsoScale = 45, same as the test above.
+
+        var result = LiveStepDetector.Result(0, emptyList(), false)
+        var t = 0L
+        // Rises from 400 to 460 in 10px steps (well under the 11.25px
+        // per-frame outlier cutoff), holds, then descends the same way --
+        // a 60px prominence, comfortably past the 6.75px ratio threshold.
+        val path = listOf(400f, 410f, 420f, 430f, 440f, 450f, 460f, 450f, 440f, 430f, 420f, 410f, 400f)
+        for (y in path) {
+            result = detector.update(frame(t, ankleL = y, ankleR = 700f, hipX = 400f, hipY = hipY))
+            t += 30L
+        }
+
+        assertEquals("gradual real motion at small torso scale should still confirm", 1, result.stepCount)
+    }
 }