From a4419b4c89cb6bfc5c04c489cd152a928eef42cb Mon Sep 17 00:00:00 2001
From: evgeny <evgeny@adaptto.ru>
Date: Tue, 20 Oct 2026 21:40:20 +0200
Subject: [PATCH] Validate Android surface timestamps in stream diagnostics

---
 .../com/utun/chat/data/StreamPlayerEngine.kt    | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt
index 78a1347d..08ce0ccb 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt
@@ -144,12 +144,23 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
                             var firstRendered = true
                             val codecRevision = frame.revision
                             try {
-                                attempt.setOnFrameRenderedListener({ _, pts, renderedNs ->
+                                attempt.setOnFrameRenderedListener({ codec, pts, renderedNs ->
                                     if (firstRendered) {
                                         firstRendered = false
+                                        val callbackUs = System.nanoTime() / 1000
+                                        val renderedUs = renderedNs / 1000
+                                        val renderClockValid = renderedUs in requestedAtUs..callbackUs
+                                        if (!renderClockValid) LogManager.addLog("WARN", "stream",
+                                            "viewer surface timestamp outside request interval id=$id PTS=$pts renderedNs=$renderedNs " +
+                                                "requestedUs=$requestedAtUs callbackUs=$callbackUs; using callback time")
                                         LogManager.addLog("INFO", "stream", "android first surface frame id=$id revision=$codecRevision " +
-                                            "PTS=$pts elapsedUs=${renderedNs / 1000 - requestedAtUs} " +
-                                            "callbackDelayUs=${System.nanoTime() / 1000 - renderedNs / 1000}")
+                                            "stage=surface_callback PTS=$pts elapsedUs=${callbackUs - requestedAtUs} " +
+                                            "renderElapsedUs=${if (renderClockValid) renderedUs - requestedAtUs else -1} " +
+                                            "callbackDelayUs=${if (renderClockValid) callbackUs - renderedUs else -1}")
+                                        try { codec.setOnFrameRenderedListener(null, null) }
+                                        catch (e: Exception) {
+                                            LogManager.addLog("WARN", "stream", "viewer surface diagnostics detach id=$id: ${e.message}")
+                                        }
                                     }
                                 }, main)
                             } catch (e: Exception) {