From 2914daa3aa594f818220d166181a6d04b9f75b78 Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Sun, 22 Feb 2026 20:37:39 +0100
Subject: [PATCH] fix short black-out when a playlist advances (WLEDMM
 specific)

* do not call strip.show(), just shedule a "show()" in the next main loop.
* experimental fix for inconsistent state when loading a preset (see upstream https://github.com/wled/WLED/issues/5200)
---
 wled00/json.cpp    | 9 ++++++---
 wled00/presets.cpp | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/wled00/json.cpp b/wled00/json.cpp
index f41c4e5c..bb0f4039 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -475,14 +475,16 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
   }
   #endif
 
-  bool onBefore = bri;
-  getVal(root["bri"], &bri);
+  bool onBefore = bri > 0;
+  //if (onBefore && briLast == 0) briLast = bri;
+  (void) getVal(root["bri"], &bri);
 
   bool on = root["on"] | (bri > 0);
   if (!on != !bri) toggleOnOff();
 
   if (root["on"].is<const char*>() && root["on"].as<const char*>()[0] == 't') {
-    if (onBefore || !bri) toggleOnOff(); // do not toggle off again if just turned on by bri (makes e.g. "{"on":"t","bri":32}" work)
+    // WLEDMM bugfix: do not toggle twice when bri > 0
+    if (onBefore && !bri) toggleOnOff(); // do not toggle off again if just turned on by bri (makes e.g. "{"on":"t","bri":32}" work)
   }
 
   if (bri && !onBefore) { // unfreeze all segments when turning on
@@ -666,6 +668,7 @@ bool deserializeState(JsonObject root, byte callMode, byte presetId)
     //do not notify here, because the first playlist entry will do
     if (root["on"].isNull()) callMode = CALL_MODE_NO_NOTIFY;
     else callMode = CALL_MODE_DIRECT_CHANGE;  // possible bugfix for playlist only containing HTTP API preset FX=~
+    stateChanged = false; // WLEDMM: prevent premature LED update, let first preset handle it
   }
 
   if (root.containsKey(F("rmcpal")) && root[F("rmcpal")].as<bool>()) {
diff --git a/wled00/presets.cpp b/wled00/presets.cpp
index c3fe1e5c..4d118f19 100644
--- a/wled00/presets.cpp
+++ b/wled00/presets.cpp
@@ -253,7 +253,7 @@ void handlePresets()
   unsigned long waitstart = millis();
   while (strip.isServicing() && millis() - waitstart < FRAMETIME_FIXED) delay(1); // wait for effects to finish updating
 
-  strip.fill(BLACK); strip.show(); // experimental: set LEDs to black while new preset loads (instead of freezing effects)
+  strip.fill(BLACK); strip.trigger(); // experimental: set LEDs to black while new preset loads (shortly freezing effects, but starts clean. Still better than a short black-out.)
 
   unsigned long start = millis();
   while (strip.isUpdating() && millis() - start < FRAMETIME_FIXED) delay(1); // wait for strip to finish updating, accessing FS during sendout causes glitches // WLEDMM delay instead of yield