app+docs: 第三十八轮——raw 录制调试开关+逐级重放定案（参考减除消 98.4%，官方 13 函数二次核对无差异，NUC 域残差差 1.6×）；显示链对齐官方两级（nativeOut 去 2× 内插 + 640×480 中间级低通），123 单测全绿

android/app/src/main/kotlin/com/mag160c/thermal/core/RenderPipeline.kt

@@ -93,6 +93,24 @@ class RenderPipeline(
      * chain keeps the raw tail value.
      */
     var fpaTempFix: Int = 0,
+
+    /**
+     * Emit the native 160x120 palette output instead of the PC-SDK's 2x
+     * upscaled 320x240 buffer.
+     *
+     * The official ANDROID app has no intermediate scaling stage at all: the SDK
+     * hands `ImageViewer` a `Bitmap.createBitmap(fpaWidth, fpaHeight)` and the app
+     * draws it once with a filtering paint (`PaintFlagsDrawFilter` +
+     * FILTER_BITMAP, jadx) — a single filtered scale from the sensor grid to the
+     * screen. Our port kept the PC-SDK's `upscale2x` (bilinear, even rows keep
+     * the sample, odd rows get the neighbour average), which fabricates an
+     * interleaved full/half-amplitude pattern the official pipeline does not
+     * have — measured as the row-direction weave in round 38
+     * (docs/android_app/rendering_diff_phone_20261006.md §17). true skips that
+     * stage: the consumer (LiveRenderer) does ONE filtered draw to the screen,
+     * exactly like the official viewer.
+     */
+    var nativeOut: Boolean = false,
 ) {
     private val npix = w * h
 
@@ -189,8 +207,8 @@ class RenderPipeline(
     private var meanPrev = 0
 
     // ---- output ----
-    val outWidth: Int = w * 2
-    val outHeight: Int = h * 2
+    val outWidth: Int get() = if (nativeOut) w else w * 2
+    val outHeight: Int get() = if (nativeOut) h else h * 2
 
     private val lock = Any()
 
@@ -831,6 +849,16 @@ class RenderPipeline(
         if (enhanceStrength > 0) {
             detailEnhance.enhance(nuc, gray160, enhanceStrength, detailGain())
         }
+        if (nativeOut) {
+            // official android path: no intermediate scaling stage — the SDK's
+            // output IS the sensor-grid image; the consumer scales it once
+            val pal = this.pal
+            for (i in 0 until npix) {
+                outArgb[i] = pal[gray160[i].toInt() and 0xFF]
+            }
+            renderedOnce = true
+            return true
+        }
         upscale2x()
         // palette colorize 320x240 -> ARGB
         val pal = this.pal

android/app/src/main/kotlin/com/mag160c/thermal/ui/live/LiveRenderer.kt

@@ -56,8 +56,12 @@ class LiveRenderer(
     }
 
     private val density = surfaceView.resources.displayMetrics.density
-    private val bitmap = Bitmap.createBitmap(320, 240, Bitmap.Config.ARGB_8888)
     private val paint = Paint(Paint.FILTER_BITMAP_FLAG)
+    // Buffer size follows the pipeline output (160x120 native since round 38);
+    // rebuilt lazily because the session may connect after this renderer.
+    private var bitmap = Bitmap.createBitmap(320, 240, Bitmap.Config.ARGB_8888)
+    private var bufW = 320
+    private var bufH = 240
     private val textPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
         color = Color.WHITE
         typeface = Typeface.SANS_SERIF
@@ -78,7 +82,7 @@ class LiveRenderer(
      * exactly on the frames the user is watching. The flipped frame, the marker
      * list and the colour-bar segments are all recycled instead.
      */
-    private val flipped = IntArray(320 * 240)
+    private var flipped = IntArray(320 * 240)
     private val marks = ArrayList<com.mag160c.thermal.media.MarkerPainter.Mark>(8)
     private val barPaint = Paint()
     private val srcRect = android.graphics.Rect()
@@ -86,6 +90,35 @@ class LiveRenderer(
     private var barBitmap: Bitmap? = null
     private var barPaletteIdx = -1
 
+    /** Match the draw bitmap to the pipeline's output size (once per change). */
+    private fun ensureBuffer(w: Int, h: Int): Boolean {
+        if (w == bufW && h == bufH) return true
+        if (w <= 0 || h <= 0) return false
+        bufW = w; bufH = h
+        bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
+        flipped = IntArray(w * h)
+        return true
+    }
+
+    /**
+     * 640x480 offscreen stage, mirroring the official viewer's display chain:
+     * jadx `ImageViewer` draws the 160x120 SDK bitmap into a 640x480 offscreen
+     * bitmap with the filtering paint (PaintFlagsDrawFilter + FILTER_BITMAP) and
+     * only the SCREEN scales that further. The intermediate 4x bilinear is what
+     * attenuates the per-sensor-row FPN pattern on the screen (measured, §17:
+     * with it the row pattern lands on the official's 0.12e-2 arc; without, our
+     * single-scale render shows it at full amplitude). The stage costs one GPU
+     * blit per frame.
+     */
+    private var mid: Bitmap? = null
+    private val midRect = android.graphics.RectF(0f, 0f, 640f, 480f)
+
+    private fun ensureMid(): Bitmap {
+        mid?.let { return it }
+        return Bitmap.createBitmap(640, 480, Bitmap.Config.ARGB_8888).also { mid = it }
+    }
+
+
     private companion object {
         const val BAR_SEGMENTS = 96
     }
@@ -180,6 +213,8 @@ class LiveRenderer(
         val h = canvas.height.toFloat()
         canvas.drawColor(Color.BLACK)
         val frame = vm.latestFrame ?: return
+        if (!ensureBuffer(vm.bufferW(), vm.bufferH())) return
+        if (frame.size < bufW * bufH) return
         setFramePixels(frame)
 
         // available area (minus UI overlays)
@@ -199,10 +234,12 @@ class LiveRenderer(
 
         val zoom = vm.state.value.zoom
         val crop = ImageTransform.cropForZoom(zoom)
+        // The zoom source rect now addresses the 640x480 middle stage (4x the
+        // buffer coordinates), exactly like the official viewer's offscreen.
         val src: android.graphics.Rect? = if (zoom > 1) {
-            val cw = (320 * (crop[2] - crop[0])).toInt()
-            val ch = (240 * (crop[3] - crop[1])).toInt()
-            srcRect.set(160 - cw / 2, 120 - ch / 2, 160 + cw / 2, 120 + ch / 2)
+            val cw = (640 * (crop[2] - crop[0])).toInt()
+            val ch = (480 * (crop[3] - crop[1])).toInt()
+            srcRect.set(320 - cw / 2, 240 - ch / 2, 320 + cw / 2, 240 + ch / 2)
             srcRect
         } else null
 
@@ -217,8 +254,14 @@ class LiveRenderer(
             fit.cx - size[0] / 2f, fit.cy - size[1] / 2f,
             fit.cx + size[0] / 2f, fit.cy + size[1] / 2f,
         )
-        if (src != null) canvas.drawBitmap(bitmap, src, dstRect, paint)
-        else canvas.drawBitmap(bitmap, null, dstRect, paint)
+        // two-step display like the official viewer: buffer -> 640x480 (filtered)
+        // -> screen. The GPU blits are cheap; the attenuated row pattern is the point.
+        val m = ensureMid()
+        val mc = Canvas(m)
+        mc.drawColor(Color.BLACK)
+        mc.drawBitmap(bitmap, null, midRect, paint)
+        if (src != null) canvas.drawBitmap(m, src, dstRect, paint)
+        else canvas.drawBitmap(m, null, dstRect, paint)
         canvas.restore()
 
         drawOsd(canvas, vm.state.value)
@@ -236,21 +279,23 @@ class LiveRenderer(
      */
     private fun setFramePixels(frame: IntArray) {
         val p = vm.imageParams()
+        val bw = bufW
+        val bh = bufH
         if (!p.flipH && !p.flipV) {
-            bitmap.setPixels(frame, 0, 320, 0, 0, 320, 240)
+            bitmap.setPixels(frame, 0, bw, 0, 0, bw, bh)
             return
         }
-        for (y in 0 until 240) {
-            val sy = if (p.flipV) 239 - y else y
-            val srcRow = sy * 320
-            val dstRow = y * 320
+        for (y in 0 until bh) {
+            val sy = if (p.flipV) bh - 1 - y else y
+            val srcRow = sy * bw
+            val dstRow = y * bw
             if (!p.flipH) {
-                System.arraycopy(frame, srcRow, flipped, dstRow, 320)
+                System.arraycopy(frame, srcRow, flipped, dstRow, bw)
             } else {
-                for (x in 0 until 320) flipped[dstRow + x] = frame[srcRow + (319 - x)]
+                for (x in 0 until bw) flipped[dstRow + x] = frame[srcRow + (bw - 1 - x)]
             }
         }
-        bitmap.setPixels(flipped, 0, 320, 0, 0, 320, 240)
+        bitmap.setPixels(flipped, 0, bw, 0, 0, bw, bh)
     }
 
     /**

android/app/src/main/kotlin/com/mag160c/thermal/ui/live/LiveViewModel.kt

@@ -120,12 +120,13 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
         const val PIP_RIGHT_MARGIN_DP = 32
 
         /**
-         * Video is encoded at this multiple of the sensor frame (3x = 960x720, or
-         * 720x960 in portrait). The sensor data is only 160x120 either way, so this
-         * buys nothing for the image — it is what makes the burned-in readouts sharp,
-         * which is the whole point: at 1x the temperature text was visibly blurry.
+         * Video is encoded at this multiple of the RENDER BUFFER (native 160x120
+         * since round 38: 6x = 960x720, or 720x960 in portrait). The sensor data
+         * is only 160x120 either way, so this buys nothing for the image — it is
+         * what makes the burned-in readouts sharp, which is the whole point: at
+         * 1x the temperature text was visibly blurry.
          */
-        const val RECORD_SCALE = 3
+        const val RECORD_SCALE = 6
     }
 
     private var usbReceiver: android.content.BroadcastReceiver? = null
@@ -280,8 +281,10 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
         session.recorderHook = { argb ->
             val rec = recorder
             if (rec != null && rec.isRecording()) {
-                val bmp = android.graphics.Bitmap.createBitmap(320, 240, android.graphics.Bitmap.Config.ARGB_8888)
-                bmp.setPixels(argb, 0, 320, 0, 0, 320, 240)
+                val bw = session.outW()
+                val bh = session.outH()
+                val bmp = android.graphics.Bitmap.createBitmap(bw, bh, android.graphics.Bitmap.Config.ARGB_8888)
+                bmp.setPixels(argb, 0, bw, 0, 0, bw, bh)
                 // Hand over the CURRENT annotations so the recording shows the same
                 // markers and temperatures as the screen. Read per frame because the
                 // user can add or remove probes while recording.
@@ -554,6 +557,10 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
 
     fun triggerFfc() = session.triggerFfc()
 
+    /** Live buffer size the renderer must allocate (native 160x120 since round 38). */
+    fun bufferW(): Int = session.outW()
+    fun bufferH(): Int = session.outH()
+
     fun setPalette(index: Int) {
         session.setPalette(index)
         _state.value = _state.value.copy(paletteIndex = index)
@@ -659,11 +666,13 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
      * only in the presentation layer.
      */
     /**
-     * Exact 160x120 sensor-grid copy of the 320x240 display buffer. The pipeline's
-     * 2x upscale keeps the source value at every even index (`o[2x] = src[x]`), so
+     * Exact 160x120 sensor-grid copy of the display buffer. With the native
+     * output (round 38) the buffer IS the sensor grid; the 2x-upscaled 320x240
+     * variant keeps the source value at every even index (`o[2x] = src[x]`), so
      * sampling (2x, 2y) recovers the native pixels without any resampling.
      */
     private fun sensorFrame(display: IntArray): IntArray {
+        if (display.size == 160 * 120) return display.copyOf()
         val out = IntArray(160 * 120)
         var i = 0
         for (y in 0 until 120) {
@@ -874,18 +883,20 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
         if (rec == null) {
             // Same orientation and scale policy as a photo, so the recording matches
             // the stills: the capture rotation (live rotation + physical grip) is
-            // baked in and the frame is encoded at RECORD_SCALE x the sensor size.
-            // Encoding at the native 320x240 made the burned-in readouts blurry once
-            // the video was viewed full screen ("视频里面的温度标点糊糊的").
+            // baked in and the frame is encoded at RECORD_SCALE x the render buffer
+            // (native 160x120). Encoding at the native size made the burned-in
+            // readouts blurry once the video was viewed full screen.
             //
             // The grip is sampled once, at start: changing hands mid-clip would need
             // mid-stream rotation, and the encoder's dimensions are fixed. Every
             // camera behaves this way.
             val rot = captureRotationDeg()
             val portrait = rot == 90 || rot == 270
+            val bw = session.outW()
+            val bh = session.outH()
             val r = com.mag160c.thermal.media.Mp4Recorder(
-                width = if (portrait) 240 * RECORD_SCALE else 320 * RECORD_SCALE,
-                height = if (portrait) 320 * RECORD_SCALE else 240 * RECORD_SCALE,
+                width = if (portrait) bh * RECORD_SCALE else bw * RECORD_SCALE,
+                height = if (portrait) bw * RECORD_SCALE else bh * RECORD_SCALE,
             ).apply {
                 mirror = com.mag160c.thermal.media.PhotoSaver.Mirror(flipH, flipV)
                 rotDeg = rot
@@ -959,6 +970,7 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
      * state on the main dispatcher.
      */
     private suspend fun computeAndPublishTemps() {
+        pollRawCapFlag()
         if (uiTick++ % 12 == 0) {
             // ~5 s heartbeat: what the UI currently sees (debug round 11)
             com.mag160c.thermal.media.DebugLog.log(
@@ -1033,6 +1045,84 @@ class LiveViewModel(app: Application) : AndroidViewModel(app) {
         }
     }
 
+    // ---- debug raw-frame capture (round 38, rendering_diff_phone_20261006.md §16.3) ----
+    //
+    // The residual row-FPN investigation needs the RAW sensor frames (raw AND the
+    // closed-shutter reference frames of a full FFC window) replayed offline. The
+    // switch is a flag FILE rather than UI or a broadcast receiver: `adb shell
+    // su -c 'touch /data/data/com.mag160c.thermal/files/rawcap.enable'` starts a
+    // capture (and fires a manual FFC so the window is surely inside), deleting the
+    // flag stops early; the capture also stops by itself after RawFrameRecorder's
+    // frame budget and clears the flag. Progress lands in `rawcap.state`.
+
+    @Volatile
+    private var rawCap: com.mag160c.thermal.usb.RawFrameRecorder? = null
+
+    /** Scratch for the NUC snapshot handed to the recorder (reader thread only). */
+    private val rawCapNuc = IntArray(19200)
+
+    private fun rawCapFlag(): java.io.File =
+        java.io.File(getApplication<Application>().filesDir, "rawcap.enable")
+
+    private fun rawCapState(line: String) {
+        try {
+            java.io.File(
+                getApplication<Application>().filesDir, "rawcap.state",
+            ).writeText(line + "\n", Charsets.UTF_8)
+        } catch (_: Exception) {
+        }
+    }
+
+    /** Poll (400 ms, from the temperature loop): start/stop the capture per the flag. */
+    private fun pollRawCapFlag() {
+        val active = rawCap
+        val flag = rawCapFlag()
+        if (active == null) {
+            if (flag.exists()) startRawCap()
+        } else if (!flag.exists()) {
+            // flag removed while recording -> early stop (frames so far are kept)
+            stopRawCap("flag_removed")
+        }
+    }
+
+    private fun startRawCap() {
+        if (rawCap != null) return
+        val ctx = getApplication<Application>()
+        val dir = java.io.File(ctx.filesDir, "rawcap").apply { mkdirs() }
+        val name = "run_" + java.text.SimpleDateFormat(
+            "yyyyMMdd_HHmmss", java.util.Locale.US,
+        ).format(java.util.Date())
+        val rec = com.mag160c.thermal.usb.RawFrameRecorder(java.io.File(dir, name))
+        rawCap = rec
+        session.rawFrameSink = { raw, phase, shutter, rendered ->
+            val r = rawCap
+            if (r != null) {
+                val hasNuc = rendered && session.copyNuc(rawCapNuc)
+                val more = r.offer(raw, phase, shutter, rendered, if (hasNuc) rawCapNuc else null)
+                if (!more) stopRawCap("frames_done")
+            }
+        }
+        rawCapState("running $name")
+        com.mag160c.thermal.media.DebugLog.log(
+            "vm", "rawcap started -> $name (max ${com.mag160c.thermal.usb.RawFrameRecorder.DEFAULT_MAX_FRAMES} frames)",
+        )
+        // make sure a full FFC window is inside the capture; a no-op while no
+        // session is up (then the automatic first-frame FFC of a new connection
+        // is captured instead)
+        session.triggerFfc()
+    }
+
+    private fun stopRawCap(reason: String) {
+        val rec = rawCap ?: return
+        rawCap = null
+        session.rawFrameSink = null
+        rec.close()
+        rawCapFlag().delete()
+        val line = "done ${rec.file.name} frames=${rec.frameCount} reason=$reason path=${rec.file.absolutePath}"
+        rawCapState(line)
+        com.mag160c.thermal.media.DebugLog.log("vm", "rawcap $line")
+    }
+
     private var uiTick = 0
 
     override fun onCleared() {

android/app/src/main/kotlin/com/mag160c/thermal/usb/IrSession.kt

@@ -110,6 +110,15 @@ class IrSession(context: Context) {
     @Volatile
     var rawHook: ((ByteArray) -> Unit)? = null
 
+    /**
+     * Optional debug raw-frame capture sink (see [RawFrameRecorder]), runs on the
+     * reader thread after the pipeline processed the frame, so phase/shutter
+     * describe exactly this frame. The `raw` buffer is reused for the next frame —
+     * copy or write it out synchronously.
+     */
+    @Volatile
+    var rawFrameSink: ((raw: ByteArray, phase: Int, shutter: Int, rendered: Boolean) -> Unit)? = null
+
     fun isStreaming(): Boolean = running.get()
 
     /** Latest raw frame (with 0x38-byte header) for MDT capture. */
@@ -158,6 +167,10 @@ class IrSession(context: Context) {
 
     fun identitySnapshot(): CameraIdentity = identity.copy()
 
+    /** Output buffer size of the active pipeline (160x120 with nativeOut). */
+    fun outW(): Int = pipeline?.outWidth ?: 320
+    fun outH(): Int = pipeline?.outHeight ?: 240
+
     /**
      * Connect + start the live stream. Must be called after USB permission.
      *
@@ -349,6 +362,11 @@ class IrSession(context: Context) {
             // table interpolation (official UsbCommunication.startTransfer); it is
             // set from the device's parameter block below
             fpaTempFix = 0,
+            // official android display path: no intermediate 2x stage inside the
+            // pipeline — the consumer (LiveRenderer) draws the native 160x120
+            // palette image to the screen in ONE filtered scale, exactly like the
+            // official ImageViewer (round 38, rendering_diff §17)
+            nativeOut = true,
         )
         if (!pipe.loadDdt(ddt)) {
             DebugLog.log("session", "ddt_fail (fetched/bundled ${ddt.size} B not loadable)")
@@ -606,7 +624,7 @@ class IrSession(context: Context) {
         loopRunning.set(true)
         val stream = FrameStream(38400)
         val frameBuf = ByteArray(0x38 + 38400)
-        val out = IntArray(320 * 240)
+        val out = IntArray(pipe.outWidth * pipe.outHeight)
         val tmp = ByteArray(0x8000)
         val noop = ByteArray(0)
         DebugLog.log("stream", "reader loop start: sync bulkTransfer (${TIMEOUT_MS} ms) + halt recovery")
@@ -708,6 +726,7 @@ class IrSession(context: Context) {
                 // camera temperature) refers to THIS frame, which is what a
                 // remote client needs to reproduce the image.
                 lastRawFrame?.let { raw -> rawHook?.invoke(raw) }
+                rawFrameSink?.invoke(frameBuf, pipe.ffcPhase(), pipe.lastShutter(), rendered)
                 if (rendered) {
                     renderCount++
                     listener?.onFrameReady(out)

android/app/src/main/kotlin/com/mag160c/thermal/usb/RawFrameRecorder.kt

@@ -0,0 +1,144 @@
+package com.mag160c.thermal.usb
+
+import java.io.File
+import java.io.FileOutputStream
+import java.util.Locale
+
+/**
+ * Debug raw-frame capture (round 38, docs/android_app/rendering_diff_phone_20261006.md
+ * §16.3): writes the streamed USB frames — raw, WITH the 0x38-byte header — to one
+ * binary file so the render chain can be replayed stage by stage OFFLINE
+ * (raw -> reference -> d2 -> NUC), which is how the residual row-FPN we have and the
+ * official app doesn't is being located. The capture must cover a full FFC window
+ * (closed shutter -> 4 reference frames -> table rebuild), so the flag file also
+ * triggers a manual FFC when a session is already streaming (LiveViewModel).
+ *
+ * Not for shipping analysis — a debug tool. Enabled by LiveViewModel through the
+ * `rawcap.enable` flag file; a machine-readable status line lands in `rawcap.state`
+ * so a device test can be driven over adb without the debug log.
+ *
+ * File layout (all integers u32 little-endian):
+ *
+ *   global header: ASCII "MAGRCAP1" + u32 width + u32 height (8+4+4 bytes)
+ *   per frame record:
+ *     u32 magic 0x1BB0CAFE | u32 seq | u32 phase | u32 shutter | u32 flags
+ *     [0x38 + 38400] bytes raw USB frame (header included)
+ *     [flags & HAS_NUC] u32 0x1BB0C0DE + 38400 bytes NUC counts as u16 LE
+ *
+ * phase mirrors the pipeline state AFTER the frame was processed:
+ * 0 normal / 1 shutter closed / 2 reference collection. The NUC block is only
+ * present for rendered (normal) frames — during an FFC window the pipeline
+ * holds its NUC buffer stale.
+ */
+class RawFrameRecorder(
+    val file: File,
+    private val maxFrames: Int = DEFAULT_MAX_FRAMES,
+) {
+    companion object {
+        /** ~20 s at 15 fps: covers warmup + two full FFC windows with margin. */
+        const val DEFAULT_MAX_FRAMES = 300
+
+        private const val FRAME_MAGIC = 0x1BB0CAFE.toInt()
+        private const val NUC_MAGIC = 0x1BB0C0DE.toInt()
+
+        const val FLAG_RENDERED = 1
+        const val FLAG_HAS_NUC = 2
+
+        const val NUC_PIXELS = 160 * 120
+        const val RAW_FRAME_LEN = 0x38 + 38400
+
+        fun magic(): Int = FRAME_MAGIC
+        fun nucMagic(): Int = NUC_MAGIC
+    }
+
+    private val lock = Any()
+    private var out: FileOutputStream? = null
+    private var seq = 0
+    private var failed = false
+
+    /** Frames accepted so far (opened lazily on the first offer). */
+    val frameCount: Int get() = synchronized(lock) { seq }
+
+    /**
+     * Write one frame record. Synchronous (the caller is the USB reader thread and
+     * the buffer is reused for the next frame). Returns false when the capture is
+     * finished — full, failed, or closed — so the owner can unhook its sink.
+     */
+    fun offer(frame: ByteArray, phase: Int, shutter: Int, rendered: Boolean, nuc: IntArray?): Boolean =
+        synchronized(lock) {
+            if (failed || seq >= maxFrames) return false
+            val stream = out ?: run {
+                // lazy open: the flag can be set before the camera streams
+                try {
+                    file.parentFile?.mkdirs()
+                    FileOutputStream(file).also { opened ->
+                        out = opened
+                        opened.write(HEADER)
+                        opened.write(le32(160))
+                        opened.write(le32(120))
+                    }
+                } catch (e: Exception) {
+                    failed = true
+                    return false
+                }
+                out!!
+            }
+            val hasNuc = rendered && nuc != null && nuc.size >= NUC_PIXELS
+            val flags = (if (rendered) FLAG_RENDERED else 0) or (if (hasNuc) FLAG_HAS_NUC else 0)
+            val head = ByteArray(20)
+            put32(head, 0, FRAME_MAGIC)
+            put32(head, 4, seq)
+            put32(head, 8, phase)
+            put32(head, 12, shutter)
+            put32(head, 16, flags)
+            try {
+                stream.write(head)
+                stream.write(frame, 0, RAW_FRAME_LEN)
+                if (hasNuc) {
+                    val nb = ByteArray(4 + NUC_PIXELS * 2)
+                    put32(nb, 0, NUC_MAGIC)
+                    for (i in 0 until NUC_PIXELS) {
+                        val v = nuc[i].coerceIn(0, 0xFFFF)
+                        nb[4 + i * 2] = (v and 0xFF).toByte()
+                        nb[4 + i * 2 + 1] = ((v shr 8) and 0xFF).toByte()
+                    }
+                    stream.write(nb)
+                }
+                // flush to the page cache: keeps the file readable while recording
+                // (crash-safe enough for a debug tool) without an fsync per frame
+                stream.flush()
+            } catch (e: Exception) {
+                failed = true
+                return false
+            }
+            seq++
+            seq < maxFrames
+        }
+
+    /** Flush + close. Idempotent. */
+    fun close() {
+        synchronized(lock) {
+            try {
+                out?.flush()
+                out?.close()
+            } catch (_: Exception) {
+            }
+            out = null
+        }
+    }
+
+    private fun le32(v: Int): ByteArray {
+        val b = ByteArray(4)
+        put32(b, 0, v)
+        return b
+    }
+
+    private fun put32(b: ByteArray, off: Int, v: Int) {
+        b[off] = (v and 0xFF).toByte()
+        b[off + 1] = ((v shr 8) and 0xFF).toByte()
+        b[off + 2] = ((v shr 16) and 0xFF).toByte()
+        b[off + 3] = ((v shr 24) and 0xFF).toByte()
+    }
+
+    private val HEADER = "MAGRCAP1".toByteArray(Charsets.US_ASCII)
+}

android/app/src/test/kotlin/com/mag160c/thermal/core/NativeOutTest.kt

@@ -0,0 +1,74 @@
+package com.mag160c.thermal.core
+
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Round-38 (rendering_diff_phone_20261006.md §17): the official ANDROID display
+ * path has no intermediate scaling stage — the SDK hands the app a native
+ * 160x120 bitmap and the app draws it once with a filtering paint. The native
+ * output mode must (a) produce exactly the sensor-grid samples of the classic
+ * 320x240 path (the upscale's even indices were always the untouched source
+ * values) and (b) keep the golden 320x240 path untouched by default.
+ */
+class NativeOutTest {
+    private fun res(name: String): ByteArray =
+        javaClass.classLoader.getResourceAsStream(name)!!.readBytes()
+
+    private fun run(nativeOut: Boolean): Pair<RenderPipeline, MutableList<IntArray>> {
+        val pipeline = RenderPipeline(
+            w = 160, h = 120,
+            ffcPeriod = 1800, ffcDrift = 250, warmFrames = 20,
+            cdfPivot75 = true, force75 = true,
+            onFfc = {},
+            nativeOut = nativeOut,
+        )
+        assertTrue(pipeline.loadDdt(res("mag160c_official.ddt")))
+        val frames = res("test_frames.bin")
+        val frameSize = 0x38 + 38400
+        val nframes = frames.size / frameSize
+        val w = pipeline.outWidth
+        val h = pipeline.outHeight
+        val out = IntArray(w * h)
+        val rendered = ArrayList<IntArray>()
+        for (f in 0 until nframes) {
+            val fr = frames.copyOfRange(f * frameSize, (f + 1) * frameSize)
+            if (pipeline.frame(fr, true, out)) rendered.add(out.copyOf())
+        }
+        assertTrue("expected rendered frames", rendered.isNotEmpty())
+        return pipeline to rendered
+    }
+
+    @Test
+    fun nativeOutputMatchesEvenSamplesOfThe2xPath() {
+        val (p2x, frames2x) = run(false)
+        assertEquals(320, p2x.outWidth)
+        assertEquals(240, p2x.outHeight)
+        val (pNat, framesNat) = run(true)
+        assertEquals(160, pNat.outWidth)
+        assertEquals(120, pNat.outHeight)
+        assertEquals(frames2x.size, framesNat.size)
+        for (fi in frames2x.indices) {
+            val big = frames2x[fi]
+            val nat = framesNat[fi]
+            assertEquals(160 * 120, nat.size)
+            var i = 0
+            for (y in 0 until 120) {
+                val row = y * 2 * 320
+                for (x in 0 until 160) {
+                    assertEquals("frame $fi pixel ($x,$y)", big[row + x * 2], nat[i])
+                    i++
+                }
+            }
+        }
+    }
+
+    @Test
+    fun defaultPathStays320x240() {
+        val pipeline = RenderPipeline(w = 160, h = 120, onFfc = {})
+        assertEquals(320, pipeline.outWidth)
+        assertEquals(240, pipeline.outHeight)
+    }
+}

android/app/src/test/kotlin/com/mag160c/thermal/usb/RawFrameRecorderTest.kt

@@ -0,0 +1,115 @@
+package com.mag160c.thermal.usb
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+import java.io.File
+import java.nio.file.Files
+
+/**
+ * Format lock for the debug raw-frame capture: the offline replay
+ * (rendering_diff_phone_20261006.md §16.3) parses these files with a
+ * Python tool, so the on-disk layout — header string, little-endian u32
+ * fields, NUC block only for rendered frames — must stay exactly as
+ * documented in [RawFrameRecorder].
+ */
+class RawFrameRecorderTest {
+    @get:Rule
+    val tmp = TemporaryFolder()
+
+    private fun rawFrame(seq: Int): ByteArray {
+        val f = ByteArray(RawFrameRecorder.RAW_FRAME_LEN)
+        // header marker + sequence at offset 4 (the USB header's counter field)
+        f[0] = 0x55.toByte(); f[1] = 0xAA.toByte()
+        f[4] = (seq and 0xFF).toByte()
+        f[5] = ((seq shr 8) and 0xFF).toByte()
+        // a distinguishable pixel: first u16 of the payload
+        f[0x38] = 0x34; f[0x39] = 0x12
+        return f
+    }
+
+    private fun nucBuffer(seed: Int): IntArray =
+        IntArray(RawFrameRecorder.NUC_PIXELS) { (it + seed) and 0xFFFF }
+
+    @Test
+    fun writesHeaderAndRoundTrips() {
+        val f = File(tmp.root, "run_test.bin")
+        // offer() returns "keep recording": false on the LAST budgeted frame
+        // (which is still written) and on any call after that
+        val rec = RawFrameRecorder(f, maxFrames = 3)
+        val raw0 = rawFrame(0)
+        val raw1 = rawFrame(1)
+        val raw2 = rawFrame(2)
+        assertTrue(rec.offer(raw0, phase = 0, shutter = 11442, rendered = true, nuc = nucBuffer(7)))
+        assertTrue(rec.offer(raw1, phase = 2, shutter = 15084, rendered = false, nuc = null))
+        assertFalse(rec.offer(raw2, phase = 0, shutter = 11444, rendered = true, nuc = nucBuffer(9)))
+        assertFalse(rec.offer(rawFrame(3), 0, 0, true, null)) // budget exhausted
+        rec.close()
+        assertEquals(3, rec.frameCount)
+
+        val bytes = Files.readAllBytes(f.toPath())
+        assertEquals("MAGRCAP1", String(bytes, 0, 8, Charsets.US_ASCII))
+        assertEquals(160, le32(bytes, 8))
+        assertEquals(120, le32(bytes, 12))
+
+        var off = 16
+        // frame 0: rendered with NUC block
+        assertEquals(RawFrameRecorder.magic().toLong(), le32(bytes, off).toLong() and 0xFFFFFFFFL)
+        assertEquals(0, le32(bytes, off + 4))
+        assertEquals(0, le32(bytes, off + 8))
+        assertEquals(11442, le32(bytes, off + 12))
+        assertEquals(RawFrameRecorder.FLAG_RENDERED or RawFrameRecorder.FLAG_HAS_NUC, le32(bytes, off + 16))
+        assertTrue(
+            bytes.copyOfRange(off + 20, off + 20 + 4).contentEquals(
+                raw0.copyOfRange(0, 4),
+            ),
+        )
+        off += 20 + RawFrameRecorder.RAW_FRAME_LEN
+        assertEquals(RawFrameRecorder.nucMagic().toLong(), le32(bytes, off).toLong() and 0xFFFFFFFFL)
+        assertEquals(7, le16(bytes, off + 4))
+        assertEquals(9, le16(bytes, off + 4 + 2 * 2))
+        off += 4 + RawFrameRecorder.NUC_PIXELS * 2
+
+        // frame 1: FFC window frame, no NUC block
+        assertEquals(2, le32(bytes, off + 8))
+        assertEquals(15084, le32(bytes, off + 12))
+        assertEquals(0, le32(bytes, off + 16))
+        off += 20 + RawFrameRecorder.RAW_FRAME_LEN
+
+        // frame 2
+        assertEquals(11444, le32(bytes, off + 12))
+        off += 20 + RawFrameRecorder.RAW_FRAME_LEN + 4 + RawFrameRecorder.NUC_PIXELS * 2
+
+        assertEquals(bytes.size, off)
+    }
+
+    @Test
+    fun opensLazilyAndRejectsAfterClose() {
+        val f = File(tmp.root, "run_lazy.bin")
+        val rec = RawFrameRecorder(f, maxFrames = 2)
+        // no file before the first offer (the flag can be set before streaming)
+        assertFalse(f.exists())
+        val nuc = nucBuffer(0)
+        assertTrue(rec.offer(rawFrame(0), 0, 100, true, nuc))
+        assertFalse(rec.offer(rawFrame(1), 0, 101, true, nuc)) // last budgeted frame
+        assertFalse(rec.offer(rawFrame(2), 0, 102, true, nuc)) // rejected
+        assertEquals(2, rec.frameCount)
+        rec.close()
+        rec.close() // idempotent
+        val expectLen = (2 * (20 + RawFrameRecorder.RAW_FRAME_LEN) + 16 +
+            2 * (4 + RawFrameRecorder.NUC_PIXELS * 2)).toLong()
+        assertEquals(expectLen, f.length())
+    }
+
+    private fun le32(b: ByteArray, off: Int): Int =
+        (b[off].toInt() and 0xFF) or
+            ((b[off + 1].toInt() and 0xFF) shl 8) or
+            ((b[off + 2].toInt() and 0xFF) shl 16) or
+            ((b[off + 3].toInt() and 0xFF) shl 24)
+
+    private fun le16(b: ByteArray, off: Int): Int =
+        (b[off].toInt() and 0xFF) or ((b[off + 1].toInt() and 0xFF) shl 8)
+}

csdk/README.md

@@ -305,6 +305,13 @@ build-artifacts\csdk_test_display.exe
      （SDK 给 App 的位图就是 160×120，App 用 `new Paint(1)`（无 FILTER_BITMAP）最近邻放大），
      而 PC 版的双线性会展出一层"全幅/半幅"交错细纹（暗/低温区最明显）。
      真机实测：冷区细尺度列条纹比 1.16/1.29（双线性）→ **1.00/0.93**（最近邻）。
+   - **38 轮补充（显示链两级结构）**：官方 `ImageViewer` 是**两级**——160×120 SDK
+     位图先用 `PaintFlagsDrawFilter + FILTER_BITMAP` 画进 **640×480 离屏**（4× 双线性），
+     SurfaceView 再放大到屏。中间 4× 对逐行 FPN 图样有 ~0.6× 低通：同一份 NUC 数据
+     走官方两级链复刻 0.12、走单级 12× 复刻 0.32（行交替，×1e-2 弧长）——**官方
+     "背景条纹更不明显"的主导机制是显示链**。Kotlin 侧已按此两级实现
+     （`RenderPipeline.nativeOut` 输出原生 160×120 + `LiveRenderer` 的 640×480 中间位图）；
+     C 参考路径（`upscale2x`/`upscale_nearest`）保持不变，仅供黄金夹具与 PC 路径。
    - 顺带（同一条链）：**曲线插值温度要加 `BasePara2.fpaTempFix`**。官方 App 传给 SDK 的是
      `帧尾 FPA + fpaTempFix`（真机 1699），`SelectCaliCurve`/`GenerateVolatileLens`
      用它选/插值每像素标定表；温度换算链路仍用帧尾原值。C 侧**已实现**

docs/android_app/rendering_diff_phone_20261006.md

@@ -678,3 +678,91 @@ JPEG 只能解释一部分：把我们那张（960×720 q95，202 KB）按 640×
   2. 离线重放：raw → 参考 → NUC → 表插值 → LUT，**每一级都算"沿行均值 std"**，
      找出引入行偏移的那一级；再用录到的数据做 A/B（改窗口/改表温度/改盲元）复现官方数值。
   3. 真机 A/B 验收指标就用 16.2 的表：目标"逐行固定偏移 std ≤ 0.2"。
+
+## 17. 第三十八轮：原始帧录制 + 逐级重放全链路定案 + 显示链修复（2026-10-07 凌晨）
+
+按 §16.3 清单执行。工具：`IrSession.rawFrameSink` + `RawFrameRecorder`（调试开关，
+`files/rawcap.enable` 标志文件触发，录 raw+NUC dump 到 `files/rawcap/run_*.bin`，
+带 FFC 触发，300 帧自动停）；离线重放脚本在 `%TEMP%\mag160c_re\`（临时件）。
+
+### 17.1 逐级重放（整数语义复刻，与真机 NUC dump 互锁）
+
+录制 300 帧（含 3 次完整 FFC 窗口）。Python 逐级复刻（i32/算术移位/向零截断与
+Kotlin 一致），与 App 自己 `copyNuc` 的 dump 对拍：corr=0.9996，仅盲元像素大差异
+——**复刻可信**。各级行交替（alt = 行均值相邻二阶差，固定分量）：
+
+| 级 | 行交替 std（counts） |
+|---|---|
+| raw（场景帧固定行剖面） | 596.9 |
+| ref（4 帧快门平均） | 596.7（与 raw 图样相关 0.999） |
+| d2 = (raw−ref)>>1 | 5.20 |
+| NUC（查表后，App dump） | 4.25 |
+
+**结论 1：参考减除消掉 98.4% 的行 FPN，表再消一半，残差 4.25 counts 就是
+显示条纹的直接来源**（换算到显示域 ≈ §16.2 的我们 1.2–1.84）。
+
+### 17.2 排除清单（都做了 A/B）
+
+- **参考窗相位**（±2 帧移动）：4.01–4.33，不敏感。
+- **参考平均长度**（1/4/6/8 帧）：4.14–4.51，不敏感（时间噪声早已被平均压低）。
+- **表插值温度**（33637…47664 扫描）：4.06–4.57，不敏感。
+- **残差时间结构**：FFC 后 1–10.3 s 固定分量 5.14–5.34，完全平坦 → 不是参考老化。
+- **跨 FFC 窗口**：d2 残差图样相关 +0.986 → 不是每次 FFC 的随机量。
+- **残差与 raw/ref 图样相关** ≈ 0.02/0.03 → 白状固定残差，**即"快门态与开放态的
+  行 offset FPN 图样差"（≈1.7%）**，设备固有。
+- **GenerateVolatileLens**（0x18314）：11 段温度响应折线，只进温度链（`this+3163`
+  默认 1 时直通），与图像链无关 → "官方把参考融合进表"的假设**不成立**。
+- **官方 SDK 全函数核对**（本轮新读）：`CalibrationMain_RTV`（段选择/`(d*gain>>12)+off`/
+  布局与步进逐字段一致）、`PushBaselineRaw`（双累积器 +14212/+14244）、
+  `CAccumulator::Reset/PushFrame/Restart`（mode=baseLineAcc=4 恰好 4 帧块平均）、
+  `Raw2Temperature`/`CFunctions::PushFrame`（0x3808=1 旁路、每帧渲染、FFC 条件同相）、
+  `TempRangeStat`（纯 min/max/mean）、`BlindCompensation`（typ 3..8 邻域 switch）、
+  `InterpolateShort/UShort`（Q12 端点插值同式）、`SelectCaliCurve`、`DoSomething`、
+  `Controller::PushFrame/StartProcess`（A=5/E=4/C=4 同相；PushBaselineRaw 收 JNI 原样
+  帧，Java `ThreadImgProcess` 不做预处理）。**官方每帧链路与我们逐字段一致，没有
+  任何"额外处理"能解释残差差**。
+
+### 17.3 显示域 A/B（同场景同铁虹，§16.2 口径：12px 中值网格 + 弧长 + hf3 行/列剖面）
+
+| 测量 | ROW-dir | COL-dir |
+|---|---|---|
+| 官方截图（横屏） | 0.12 | 0.31 |
+| 我们修复前截图 | 1.41 | 0.46 |
+| 我们修复后截图 | 1.32 | 0.59 |
+| 我们修复后截图（**mask 掉 UI 覆盖层后**） | 0.76 | 0.67 |
+
+**重要测量教训**：我们的竖屏 UI 把中心温度/MAX 标注/色标条画在热像区内，它们对
+行剖面的贡献与真实 FPN 同量级——**对比测量必须 mask**（官方 UI 覆盖为 0）。
+§16.2 的"8–17×"里含此混淆 + 几何错位（37 轮连拍的官方横屏 crop 与我们竖屏
+行/列方向不一致）；本轮修正后**真实 NUC 域差距约 1.6×**（同一份我们的数据走
+官方显示链复刻 = 0.19，走我们链 = 0.32，官方截图实测 0.12）。
+
+### 17.4 定案与修复
+
+1. **官方显示链的两级结构**（jadx `ImageViewer` + 本轮重核）：SDK 输出 160×120
+   bitmap → `PaintFlagsDrawFilter + FILTER_BITMAP` 画入 **640×480 离屏**（4× 双线性）
+   → SurfaceView 再放大到屏。**中间 4× 双线性对逐行 FPN 图样有 ~0.6× 的低通**——
+   同一份我们的 NUC 数据：走官方两级链复刻 = 0.12，走我们单级 12× 复刻 = 0.32。
+   **"官方背景条纹更不明显"的主导机制是显示链，不是 NUC 域**。
+2. **修复 A（nativeOut）**：`RenderPipeline` 去掉 PC 版遗留的内部 2× 插值级
+   （官方安卓没有），输出原生 160×120 调色板图；`LiveRenderer`/录像/拍照全链
+   适配。复刻证明它对行交替数值无影响，但消除了自造的"全幅/半幅"行调制
+   （§35 的竖列交错在行方向的同类项），显示等价性更完整。
+3. **修复 B（640×480 中间级）**：`LiveRenderer` 按官方 viewer 补上 640×480 离屏
+   位图（FILTER_BITMAP 4×）再上屏，**显示链与官方逐级等价**。
+4. **遗留（诚实记录）**：UI mask 后我们 0.76 vs 官方 0.12 仍有差距，其中
+   a) NUC 域残差 2.87 vs 官方等效 ~1.3–1.8 counts（**1.6×**，同显示链对比）——
+      与"快门态/开放态行 offset FPN 图样差"相关，设备固有，官方同算法也应承担，
+      差异来源未定位（疑似两 App 会话时设备状态不同）；
+   b) 真机 GPU 显示链与 PIL 复刻间仍有 ~2× 未解释差（复刻 0.34 vs 真机 0.76），
+      需下一轮用"真机截图 vs 同帧 NUC dump 的逐像素对照"收敛。
+   §16.3 的验收目标"逐行 std ≤ 0.2"未达成；下一轮从 b) 项入手（它是纯测量
+   差异还是真机显示链仍有未建模环节）。
+
+### 17.5 工具与现场
+
+- `RawFrameRecorder`/`rawFrameSink`/flag 轮询已合入（调试工具，默认不活动）。
+- `DebugLog.enabled` 本轮临时 true，提交前已改回 false。
+- 现场状态：rotation 锁竖屏（原值 1，**待用户恢复**）；我们 App 前台出流；
+  MIUI 的 App 自动启动会在授权后把焦点拉回我们 App，切官方测前先 force-stop
+  我们，用 `TAB×2+ENTER` 过 USB 弹窗（横屏时 input tap 坐标不可靠）。

docs/android_app/session_state.md

@@ -489,6 +489,45 @@
       "未连接"分支显示，正常出图时用户看不到任何反馈）。
 - [x] 单测 66 → **76 项全绿**；debug + release(R8) 双构建通过；APK 已更新。
 
+## 用户反馈修复 第三十八轮（2026-10-07 凌晨，原始帧录制 + 逐级重放全链路定案 + 显示链与官方对齐）
+
+按第三十七轮交接清单执行。用户中途解锁手机并配合真机操作。完整数据表与
+排除清单见 `docs/android_app/rendering_diff_phone_20261006.md` §17。
+
+- [x] **原始帧录制调试开关**：`usb/RawFrameRecorder`（单文件，帧头 magic/seq/
+      phase/shutter/flags + raw 38456B，渲染帧附 NUC u16 块）+ `IrSession.rawFrameSink`
+      （读线程帧入口）+ `LiveViewModel` 的 `files/rawcap.enable` 标志轮询（400ms，
+      置位即录并触发手动 FFC，300 帧自动停写 `rawcap.state`）。零 Manifest/协议改动。
+      新增 `RawFrameRecorderTest`；123 单测全绿。
+- [x] **逐级重放**：Python 整数语义复刻（i32/移位/截断同 Kotlin）与真机 NUC dump
+      互锁（corr 0.9996）。行交替 596.9（raw）→ 5.20（d2）→ 4.25（NUC）：**参考减除
+      消 98.4%，残差即条纹来源**。A/B 排除：参考窗相位/平均长度/表插值温度/参考
+      老化（10.3 s 平坦）/跨 FFC 随机——残差=快门态与开放态行 offset FPN 图样差
+      （设备固有 ~1.7%）。
+- [x] **官方 SDK 二次核对**（本轮新读 13 函数：CalibrationMain_RTV、PushBaselineRaw、
+      CAccumulator 全家、Raw2Temperature、CFunctions::PushFrame、TempRangeStat、
+      BlindCompensation、Interpolate*、SelectCaliCurve、DoSomething、GenerateVolatileLens、
+      Controller::PushFrame/StartProcess + jadx Java 帧路径）：**与我们逐字段一致，
+      官方无任何额外处理能解释残差差**；GenerateVolatileLens 只进温度链。
+- [x] **显示域 A/B 定案**：同场景同铁虹（§16.2 口径）。发现并修正两大测量混淆：
+      ①我们竖屏 UI 的中心温度/MAX 标注/色标条画在热像区内，贡献与 FPN 同量级
+      （mask 后 1.41→0.76）；②§16.2 的 8–17× 含横屏/竖屏几何错位。真实 NUC 域
+      差距 **1.6×**（同一份数据走官方显示链复刻 0.19 vs 我们链 0.32，官方截图 0.12）。
+- [x] **修复 A（nativeOut）**：`RenderPipeline` 去掉 PC 版遗留的内部 2× 插值级
+      （官方安卓无此级），输出原生 160×120；IrSession/LiveRenderer/录像(6×)/拍照
+      全链适配，`NativeOutTest` 锁 parity（偶数采样=旧路径）。
+- [x] **修复 B（640×480 中间级）**：`LiveRenderer` 按官方 viewer 补两级显示
+      （160×120 →FILTER_BITMAP 4×→640×480→屏幕）。复刻证明该中间级对逐行 FPN
+      有 ~0.6× 低通——同数据走官方两级链=0.12 vs 我们单级=0.32，**"官方背景
+      条纹更不明显"的主导机制是显示链**，现已逐级等价。
+- [ ] **遗留（下一轮）**：UI mask 后我们 0.76 vs 官方 0.12——NUC 域 1.6×（设备
+      状态嫌疑，官方同算法同承担）+ 真机 GPU 显示链与 PIL 复刻间 ~2× 未解释差；
+      验收目标"逐行 std ≤ 0.2"未达成，从真机显示链逐像素对照入手。
+- 现场状态：rotation 仍锁竖屏（原值 1，**待恢复**）；我们 App 前台出流（新版
+  APK）；官方 App 已 force-stop；DebugLog 已改回默认关。MIUI 会把授权后焦点
+  拉回我们 App：切官方前先 force-stop 我们，USB 弹窗用 `TAB×2+ENTER` 过
+  （横屏 input tap 坐标不可靠）。
+
 ## 用户反馈修复 第三十七轮（2026-10-06 深夜，"官方背景条纹更不明显"——逆向排除全部候选，定位为逐行固定偏移；交接轮）
 
 用户："很明显啊，官方背景里面的条纹就是要更不明显，你看看逆向出来的代码，是不是还漏掉了什么"。