diff --git a/tools/chatgui/src/stream_publish_engine.cpp b/tools/chatgui/src/stream_publish_engine.cpp
index da71e4cc..f2d94b96 100644
--- a/tools/chatgui/src/stream_publish_engine.cpp
+++ b/tools/chatgui/src/stream_publish_engine.cpp
@@ -91,11 +91,6 @@ struct StreamPublishEngine::Impl {
     std::atomic<unsigned> audioDropped{0}, audioMissing{0};
     std::atomic<int64_t> lastAudioAt{0};
     AudioEventQueue<Audio, 32> audio;
-    std::condition_variable imageWake;
-    QVideoFrame imageInput;
-    uint64_t imageGeneration = 0;
-    int64_t imagePts = -1;
-    bool imagePending = false, imageStop = false, imageDrawCursor = false;
     uint64_t id = 0, group = 0, generation = 0, sourceGeneration = 0, confirmedGeneration = 0, frameGeneration = 0, audioSequence = 0;
     int64_t origin = 0, started = 0, framePts = -1, backendOrigin = -1, backendAnchor = -1;
     int64_t audioAnchor = -1;
@@ -129,6 +124,12 @@ struct StreamPublishEngine::Impl {
     QList<int> codecs;
     stream_publisher_status stats{};
 #ifdef HAVE_STREAM_CAPTURE
+    // Очередь преобразования принадлежит capture backend; без Qt Multimedia нет ни QVideoFrame, ни её worker.
+    std::condition_variable imageWake;
+    QVideoFrame imageInput;
+    uint64_t imageGeneration = 0;
+    int64_t imagePts = -1;
+    bool imagePending = false, imageStop = false, imageDrawCursor = false;
     std::unique_ptr<QMediaCaptureSession> session;
     std::unique_ptr<QVideoSink> sink;
     std::unique_ptr<QCamera> camera;
@@ -209,6 +210,7 @@ StreamPublishEngine::StreamPublishEngine(QObject* parent) : QObject(parent), m(s
     m->imageThread->start();
 #else
     m->imageJoined = true;
+    DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop stream capture unavailable in this build; image worker disabled");
 #endif
 }
 StreamPublishEngine::~StreamPublishEngine() {
diff --git a/tools/chatgui/tests/test_stream_publish.cpp b/tools/chatgui/tests/test_stream_publish.cpp
index 40aa13ec..4258eae7 100644
--- a/tools/chatgui/tests/test_stream_publish.cpp
+++ b/tools/chatgui/tests/test_stream_publish.cpp
@@ -195,6 +195,30 @@ private slots:
         sqlite3_finalize(statement); QVERIFY(group); QVERIFY(gui_stream_attach(inst)); uasync_mark_running(ua);
         connect(&poll, &QTimer::timeout, this, [this] { uasync_poll(ua, 0); }); poll.start(1);
     }
+#ifndef HAVE_STREAM_CAPTURE
+    void captureUnavailableRefusesPublication() {
+        StreamPublishEngine engine;
+        QVERIFY(!StreamPublishEngine::supported()); QVERIFY(StreamPublishEngine::sources().isEmpty());
+        QVERIFY(engine.codecs().isEmpty()); QVERIFY(!engine.previewFrame().isValid());
+        StreamPublishWindow window(&engine, group); window.show();
+        auto* source = window.findChild<QComboBox*>(QStringLiteral("streamVideoSource"));
+        QVERIFY(source); QCOMPARE(source->count(), 0);
+        QPushButton* start = nullptr;
+        for (auto* button : window.findChildren<QPushButton*>())
+            if (button->text() == QCoreApplication::translate("ChatGui", "Start stream")) start = button;
+        QVERIFY(start); QVERIFY(!start->isEnabled());
+        QSignalSpy errors(&engine, &StreamPublishEngine::errorOccurred);
+        QSignalSpy states(&engine, &StreamPublishEngine::stateChanged);
+        QTest::mouseClick(start, Qt::LeftButton); QCOMPARE(errors.count(), 0);
+        QVERIFY(!engine.start(group, StreamPublishConfig{}));
+        QCOMPARE(errors.count(), 1); QVERIFY(!errors.front().front().toString().isEmpty());
+        QTest::qWait(120); QVERIFY(!engine.active()); QVERIFY(!engine.running()); QCOMPARE(engine.group(), uint64_t(0));
+        QCOMPARE(states.count(), 0); QCOMPARE(engine.videoBitrate(), uint64_t(0)); QCOMPARE(engine.videoMaxQp(), -1);
+        AudioCaptureLease microphone; QVERIFY(microphone.acquire()); microphone.release();
+        engine.stop(); engine.stop(); QVERIFY(!engine.active());
+        DEBUG_INFO(DEBUG_CATEGORY_STREAM, "disabled capture verified: UI start disabled, API refused, actor and microphone unowned");
+    }
+#endif
     void amfDriverDiagnosticsRespectCategoryFilter() {
 #ifdef HAVE_FFMPEG
         video_ffmpeg_init();