Present desktop video sequentially through GUI paint acknowledgement

tools/chatgui/src/call_video_engine.cpp

@@ -36,6 +36,8 @@ struct CallVideoEngine::Impl {
     int64_t shownPts = -1;
     uint64_t publicationEpoch = 0;
     bool publicationPending = false;
+    bool presentationDriven = false;
+    uint64_t publicationSerial = 0;
     unsigned publicationOverwritten = 0; // Только под lock: выбранные кадры, заменённые до GUI callback.
     int64_t publicationQueuedAt = 0;
     int64_t shownAt = 0;
@@ -88,19 +90,30 @@ CallVideoEngine::CallVideoEngine(QObject* parent) : QObject(parent), m(std::make
 #endif
 }
 CallVideoEngine::~CallVideoEngine() { stop(); }
-// В GUI одновременно не больше одного уведомления; при паузе UI остаётся последний выбранный кадр.
-void CallVideoEngine::publishImage(const QImage& image, int64_t pts) {
-    uint64_t epoch;
+void CallVideoEngine::setPresentationDriven(bool enabled) {
+    std::lock_guard<std::mutex> guard(m->lock); m->presentationDriven = enabled;
+}
+void CallVideoEngine::imagePresented(quint64 serial) {
     { std::lock_guard<std::mutex> guard(m->lock);
+      if (serial != m->publicationSerial) return;
+      m->publicationPending = false; }
+    m->wake.notify_all();
+}
+// Только один кадр до подтверждения рисования: GUI не заменяет ещё не показанное изображение.
+void CallVideoEngine::publishImage(const QImage& image, int64_t pts) {
+    uint64_t epoch, serial;
+    { std::unique_lock<std::mutex> guard(m->lock);
+      m->wake.wait(guard, [this] { return !m->running || !m->publicationPending; });
+      if (!m->running) return;
       m->shown = image; m->shownPts = pts; m->shownAt = nowUs();
-      if (m->publicationPending) { ++m->publicationOverwritten; return; }
-      m->publicationPending = true; m->publicationQueuedAt = m->shownAt; epoch = m->publicationEpoch; }
-    QMetaObject::invokeMethod(this, [this, epoch] {
+      m->publicationPending = true; m->publicationQueuedAt = m->shownAt; epoch = m->publicationEpoch;
+      serial = ++m->publicationSerial; }
+    QMetaObject::invokeMethod(this, [this, epoch, serial] {
         QImage image; int64_t pts, selected, queued; unsigned overwritten;
         { std::lock_guard<std::mutex> guard(m->lock);
           if (epoch != m->publicationEpoch) return;
           image = m->shown; pts = m->shownPts; selected = m->shownAt; queued = m->publicationQueuedAt;
-          overwritten = m->publicationOverwritten; m->publicationOverwritten = 0; m->publicationPending = false; }
+          overwritten = m->publicationOverwritten; m->publicationOverwritten = 0; }
         const int64_t now = nowUs(), wait = now - queued;
         ++m->uiPublished; m->uiWaitMax = std::max(m->uiWaitMax, wait);
         if (m->uiLastAt) m->uiGapMax = std::max(m->uiGapMax, now - m->uiLastAt);
@@ -110,7 +123,10 @@ void CallVideoEngine::publishImage(const QImage& image, int64_t pts) {
                 "selected_age_us=%lld pts=%lld mono_us=%lld", (unsigned long long)m->id, overwritten,
                 (long long)wait, (long long)(now - selected), (long long)pts, (long long)now);
         m->uiOverwritten += overwritten;
-        emit imageChanged(image);
+        emit imageChanged(image, serial);
+        bool driven;
+        { std::lock_guard<std::mutex> guard(m->lock); driven = m->presentationDriven; }
+        if (!driven || image.isNull()) imagePresented(serial);
         if (!m->uiReportAt) m->uiReportAt = now;
         if (now - m->uiReportAt >= 1000000) {
             DEBUG_DEBUG(DEBUG_CATEGORY_CALL, "video GUI delivery call=%llu interval_us=%lld published=%u overwritten=%u "
@@ -142,12 +158,13 @@ void CallVideoEngine::closeCamera() {
 }
 void CallVideoEngine::stop() {
     m->running = false; m_timer.stop(); closeCamera();
+    m->wake.notify_all();
     if (m->tx.joinable()) m->tx.join();
     if (m->rx.joinable()) m->rx.join();
     if (m->id) call_video_port_close(m->id);
     { std::lock_guard<std::mutex> guard(m->lock);
       ++m->publicationEpoch; m->publicationPending = false; m->publicationOverwritten = 0; m->shown = {}; m->shownPts = -1; }
-    m->id = 0; m->enabled = false; emit imageChanged({});
+    m->id = 0; m->enabled = false; emit imageChanged({}, 0);
 }
 void CallVideoEngine::setVideo(bool enabled, const QByteArray& cameraId, int width, int height, int codec) {
     const bool active = enabled && m->running;
@@ -341,7 +358,7 @@ void CallVideoEngine::receive() {
     uint64_t reportedGeneration = 0, rejectedGeneration = 0;
     while (m->running) {
         if (requestedWake) wakeLateMax = std::max(wakeLateMax, nowUs() - requestedWake);
-        // Один кадр ждёт своего срока, второй позволяет пропустить устаревший показ после паузы CPU.
+        // Малый decoded lookahead; накопленный долг остаётся в encoded FIFO.
         while (pictures.size() < 2 && m->running) {
             call_video_frame packet{};
             if (call_video_port_pull(m->id, &packet) == 1) {
@@ -380,7 +397,7 @@ void CallVideoEngine::receive() {
             reportAt = now; decoded = 0; decodeMax = rxAgeMax = wakeLateMax = 0;
         }
         auto action = call_video_playout_poll(&playout, pictures.empty() ? nullptr : &pictures.front().timing,
-            pictures.size() > 1 ? &pictures[1].timing : nullptr, now, clock.valid, clock.pts_us);
+            pictures.size() > 1 ? &pictures[1].timing : nullptr, now, &clock);
         if (action != CALL_VIDEO_PLAYOUT_WAIT) {
             if (action == CALL_VIDEO_PLAYOUT_SHOW) {
                 const auto& f = pictures.front(); publishImage(f.image, f.timing.pts_us); lastPictureAt = now;

tools/chatgui/src/call_video_engine.h

@@ -14,9 +14,11 @@ public:
     void start(quint64 id);
     void stop();
     void setVideo(bool enabled, const QByteArray& camera, int width, int height, int codec);
+    void setPresentationDriven(bool enabled); // Окно подтверждает рисование; без окна достаточно доставки signal.
+    void imagePresented(quint64 serial);
 signals:
     void camerasChanged(const CallCameraDevices& devices);
-    void imageChanged(const QImage& image);
+    void imageChanged(const QImage& image, quint64 serial);
     void localImageChanged(const QImage& image);
     void statusChanged(const QString& status);
 private:

tools/chatgui/src/callwindow.cpp

@@ -44,7 +44,14 @@ public:
         resize(qMin(1100, available.width() * 9 / 10), qMin(800, available.height() * 9 / 10));
     }
     QImage remote, local;
+    CallVideoEngine* engine = nullptr;
+    quint64 serial = 0;
 protected:
+    void hideEvent(QHideEvent* event) override { presented(); QWidget::hideEvent(event); }
+    void changeEvent(QEvent* event) override {
+        QWidget::changeEvent(event);
+        if (isMinimized()) presented();
+    }
     void closeEvent(QCloseEvent* event) override {
         DEBUG_INFO(DEBUG_CATEGORY_CALL, "call video window closed; call continues"); event->accept();
     }
@@ -69,8 +76,12 @@ protected:
             QRect target(QPoint(videoRect.right() - preview.width() - 12, videoRect.top() + 12), preview);
             painter.setPen(QPen(Qt::white, 2)); painter.drawRect(target.adjusted(-1, -1, 1, 1)); painter.drawImage(target, local);
         }
+        painter.end(); presented();
     }
 private:
+    void presented() {
+        if (engine && serial) { engine->imagePresented(serial); serial = 0; }
+    }
     void toggleFullScreen() {
         if (isFullScreen()) { showNormal(); if (!m_geometry.isEmpty()) restoreGeometry(m_geometry); }
         else { m_geometry = saveGeometry(); showFullScreen(); }
@@ -271,6 +282,7 @@ CallWindow::CallWindow(QWidget* parent)
     lay->addWidget(m_bgpPathLabel);
     lay->addWidget(m_statsLabel);
     m_video = new CallVideoEngine(this);
+    m_video->setPresentationDriven(true); m_videoWindow->engine = m_video;
     m_localPreview = new QLabel(this); m_localPreview->setAlignment(Qt::AlignCenter); m_localPreview->hide();
     lay->addWidget(m_localPreview, 0, Qt::AlignHCenter);
     m_videoStatus = new QLabel(this); m_videoStatus->setWordWrap(true); lay->addWidget(m_videoStatus);
@@ -317,10 +329,12 @@ CallWindow::CallWindow(QWidget* parent)
     connect(m_video, &CallVideoEngine::statusChanged, this, [this](const QString& text) {
         m_videoStatus->setText(text); m_videoStatus->setVisible(m_state == Active && !text.isEmpty());
     });
-    connect(m_video, &CallVideoEngine::imageChanged, this, [this](const QImage& image) {
+    connect(m_video, &CallVideoEngine::imageChanged, this, [this](const QImage& image, quint64 serial) {
         bool changed = m_remoteImage.isNull() != image.isNull(); m_remoteImage = image;
-        m_videoWindow->remote = image; m_videoWindow->update();
+        m_videoWindow->remote = image; m_videoWindow->serial = serial; m_videoWindow->update();
         if (changed) updateVideoPresentation();
+        // Скрытое окно продолжает принимать поток, не ждёт невозможного paintEvent.
+        if (!m_videoWindow->isVisible() || m_videoWindow->isMinimized()) m_video->imagePresented(serial);
         update();
     });
     connect(m_video, &CallVideoEngine::localImageChanged, this, [this](const QImage& image) {