Implement dual output for camera using QVideoWidget and QVideoSink, add camera permission handling, and enhance overlay error messaging

duck_preview/app.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import sys
 
 from PySide6.QtCore import QTimer
+from PySide6.QtMultimedia import QVideoSink
 from PySide6.QtWidgets import QApplication
 
 from duck_preview.camera.service import CameraService
@@ -18,18 +19,22 @@ def main() -> None:
     app.setApplicationName("Duck Preview")
 
     camera = CameraService()
+    video_sink = QVideoSink()
     dispatcher = FrameDispatcher()
     telemetry = TelemetryCollector()
     video_widget = VideoWidget()
     overlay = OverlayWidget()
 
-    camera.sink.videoFrameChanged.connect(dispatcher.on_frame)
+    camera.set_video_widget(video_widget)
+    camera.set_video_sink(video_sink)
 
+    video_sink.videoFrameChanged.connect(dispatcher.on_frame)
     dispatcher.subscribe(telemetry.on_frame)
-    dispatcher.subscribe(video_widget.on_frame)
 
     window = MainWindow(camera, video_widget, overlay)
 
+    camera.error_occurred.connect(lambda msg: overlay.set_metrics({"error": msg}))
+
     metrics_timer = QTimer()
     metrics_timer.timeout.connect(lambda: overlay.set_metrics(telemetry.metrics()))
     metrics_timer.start(200)

duck_preview/camera/service.py

@@ -9,6 +9,7 @@ from PySide6.QtMultimedia import (
     QMediaDevices,
     QVideoSink,
 )
+from PySide6.QtMultimediaWidgets import QVideoWidget
 
 
 class CameraService(QObject):
@@ -17,18 +18,18 @@ class CameraService(QObject):
     def __init__(self, parent: QObject | None = None) -> None:
         super().__init__(parent)
         self._session = QMediaCaptureSession()
-        self._sink = QVideoSink()
-        self._session.setVideoOutput(self._sink)
         self._camera: QCamera | None = None
 
-    @property
-    def sink(self) -> QVideoSink:
-        return self._sink
-
     @property
     def session(self) -> QMediaCaptureSession:
         return self._session
 
+    def set_video_widget(self, widget: QVideoWidget) -> None:
+        self._session.setVideoOutput(widget)
+
+    def set_video_sink(self, sink: QVideoSink) -> None:
+        self._session.setVideoSink(sink)
+
     @staticmethod
     def available_cameras() -> list[QCameraDevice]:
         return QMediaDevices.videoInputs()

duck_preview/main_window.py

@@ -1,8 +1,9 @@
 from __future__ import annotations
 
+from PySide6.QtCore import QCameraPermission, Qt
 from PySide6.QtGui import QAction, QCloseEvent
 from PySide6.QtMultimedia import QCameraDevice, QMediaDevices
-from PySide6.QtWidgets import QGridLayout, QMainWindow, QWidget
+from PySide6.QtWidgets import QApplication, QGridLayout, QMainWindow, QWidget
 
 from duck_preview.camera.service import CameraService
 from duck_preview.rendering.overlay import OverlayWidget
@@ -70,8 +71,28 @@ class MainWindow(QMainWindow):
             self._camera_menu.addAction(action)
 
     def _on_camera_selected(self, device: QCameraDevice) -> None:
-        self._camera.start(device)
+        self._request_camera_permission(device)
-        self._rebuild_resolution_menu(device)
+
+    def _request_camera_permission(self, device: QCameraDevice) -> None:
+        perm = QCameraPermission()
+        match QApplication.checkPermission(perm):
+            case Qt.PermissionStatus.Undetermined:
+                QApplication.requestPermission(
+                    perm, self, lambda: self._request_camera_permission(device)
+                )
+            case Qt.PermissionStatus.Denied:
+                self._overlay.set_metrics(
+                    {
+                        "error": (
+                            "Camera permission denied.\n"
+                            "Grant access in System Settings > "
+                            "Privacy & Security > Camera"
+                        )
+                    }
+                )
+            case Qt.PermissionStatus.Granted:
+                self._camera.start(device)
+                self._rebuild_resolution_menu(device)
 
     def _rebuild_resolution_menu(self, device: QCameraDevice) -> None:
         self._resolution_menu.clear()

duck_preview/rendering/overlay.py

@@ -11,13 +11,13 @@ class OverlayWidget(QWidget):
         self.setAttribute(Qt.WA_TransparentForMouseEvents)
         self.setAttribute(Qt.WA_NoSystemBackground)
         self._visible = True
-        self._metrics: dict[str, float | int] = {}
+        self._metrics: dict[str, float | int | str] = {}
 
     def set_visible(self, visible: bool) -> None:
         self._visible = visible
         self.update()
 
-    def set_metrics(self, metrics: dict[str, float | int]) -> None:
+    def set_metrics(self, metrics: dict[str, float | int | str]) -> None:
         self._metrics = metrics
         self.update()
 
@@ -25,16 +25,22 @@ class OverlayWidget(QWidget):
         if not self._visible or not self._metrics:
             return
 
+        painter = QPainter(self)
+        painter.setRenderHint(QPainter.TextAntialiasing)
+
+        if "error" in self._metrics:
+            self._paint_error(painter)
+        else:
+            self._paint_metrics(painter)
+
+    def _paint_metrics(self, painter: QPainter) -> None:
         lines = [
             f"FPS:     {self._metrics.get('fps', 0):>7}",
             f"Frame:   {self._metrics.get('frame_time_ms', 0):>7.1f} ms",
             f"Frames:  {self._metrics.get('frame_count', 0):>7}",
         ]
 
-        painter = QPainter(self)
+        font = QFont("monospace", 11)
-        painter.setRenderHint(QPainter.TextAntialiasing)
-
-        font = QFont("Consolas", 11)
         painter.setFont(font)
         fm = QFontMetrics(font)
 
@@ -42,8 +48,26 @@ class OverlayWidget(QWidget):
         text_height = len(lines) * (fm.height() + 6) + 12
 
         painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 160))
-
         painter.setPen(QColor(0, 255, 0))
+
+        for i, line in enumerate(lines):
+            y = 22 + i * (fm.height() + 6)
+            painter.drawText(16, y, line)
+
+    def _paint_error(self, painter: QPainter) -> None:
+        msg = str(self._metrics.get("error", "Unknown error"))
+        lines = msg.split("\n")
+
+        font = QFont("monospace", 12)
+        painter.setFont(font)
+        fm = QFontMetrics(font)
+
+        text_width = max(fm.horizontalAdvance(line) for line in lines) + 24
+        text_height = len(lines) * (fm.height() + 6) + 12
+
+        painter.fillRect(8, 8, text_width, text_height, QColor(0, 0, 0, 200))
+        painter.setPen(QColor(200, 50, 50))
+
         for i, line in enumerate(lines):
             y = 22 + i * (fm.height() + 6)
             painter.drawText(16, y, line)

duck_preview/rendering/video_widget.py

@@ -1,39 +1,10 @@
 from __future__ import annotations
 
-from PySide6.QtCore import Qt
+from PySide6.QtMultimediaWidgets import QVideoWidget
-from PySide6.QtGui import QColor, QImage, QPainter
-from PySide6.QtMultimedia import QVideoFrame
 from PySide6.QtWidgets import QWidget
 
 
-class VideoWidget(QWidget):
+class VideoWidget(QVideoWidget):
     def __init__(self, parent: QWidget | None = None) -> None:
         super().__init__(parent)
-        self._frame: QImage | None = None
-        self.setAttribute(Qt.WA_OpaquePaintEvent)
         self.setMinimumSize(320, 240)
-
-    def on_frame(self, frame: QVideoFrame) -> None:
-        image = frame.toImage()
-        if not image.isNull():
-            self._frame = image
-            self.update()
-
-    def paintEvent(self, event) -> None:  # noqa: N802
-        painter = QPainter(self)
-        painter.setRenderHint(QPainter.SmoothPixmapTransform)
-
-        if self._frame is not None:
-            painter.fillRect(self.rect(), QColor(0, 0, 0))
-            scaled = self._frame.scaled(
-                self.size(),
-                Qt.KeepAspectRatio,
-                Qt.SmoothTransformation,
-            )
-            x = (self.width() - scaled.width()) // 2
-            y = (self.height() - scaled.height()) // 2
-            painter.drawImage(x, y, scaled)
-        else:
-            painter.fillRect(self.rect(), QColor(20, 20, 20))
-            painter.setPen(QColor(100, 100, 100))
-            painter.drawText(self.rect(), Qt.AlignCenter, "No camera feed")

notes/02-mvp-mac-plan.md

@@ -0,0 +1,212 @@
+# Plan — macOS fix + QVideoWidget + QVideoSink dual output
+
+## Cel
+
+Przywrócić działanie kamery na macOS (Elgato) przez:
+1. Przejście z manualnego `QPainter` renderowania na natywny `QVideoWidget`
+2. Dodanie `QVideoSink` jako drugiego wyjścia (frame access dla telemetrii)
+3. Obsługa `QCameraPermission` (Qt 6.5+)
+4. Dokumentacja packagingu przez `pyside6-deploy` na macOS
+
+## Kolejność implementacji
+
+### 1. camera/service.py
+
+```python
+class CameraService(QObject):
+    error_occurred = Signal(str)
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self._session = QMediaCaptureSession()
+        self._camera: QCamera | None = None
+
+    def set_video_widget(self, widget: QVideoWidget) -> None:
+        self._session.setVideoOutput(widget)
+
+    def set_video_sink(self, sink: QVideoSink) -> None:
+        self._session.setVideoSink(sink)
+
+    @property
+    def session(self) -> QMediaCaptureSession:
+        return self._session
+
+    @staticmethod
+    def available_cameras() -> list[QCameraDevice]:
+        return QMediaDevices.videoInputs()
+
+    def is_active(self) -> bool:
+        return self._camera is not None and self._camera.isActive()
+
+    def start(self, device: QCameraDevice) -> None:
+        self.stop()
+        self._camera = QCamera(device, self)
+        self._camera.errorOccurred.connect(self._on_error)
+        self._session.setCamera(self._camera)
+        self._camera.start()
+
+    def stop(self) -> None:
+        if self._camera is not None:
+            self._camera.stop()
+            self._session.setCamera(None)
+            self._camera.deleteLater()
+            self._camera = None
+
+    def set_camera_format(self, fmt: QCameraFormat) -> None:
+        if self._camera is not None:
+            self._camera.setCameraFormat(fmt)
+
+    def _on_error(self, error, error_string):
+        self.error_occurred.emit(error_string)
+```
+
+Zmiany:
+- Usunięto `self._sink` z `__init__`
+- Usunięto `self._session.setVideoOutput(self._sink)`
+- Dodano `set_video_widget(widget)` → `session.setVideoOutput(widget)`
+- Dodano `set_video_sink(sink)` → `session.setVideoSink(sink)`
+
+### 2. rendering/video_widget.py
+
+```python
+from __future__ import annotations
+
+from PySide6.QtMultimediaWidgets import QVideoWidget
+
+
+class VideoWidget(QVideoWidget):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setMinimumSize(320, 240)
+```
+
+Zmiany:
+- Dziedziczy po `QVideoWidget` zamiast `QWidget`
+- Usunięto `on_frame(frame)` — nie potrzeba, renderowanie natywne
+- Usunięto `paintEvent` — nie potrzeba, robi to Qt
+- Usunięto `QImage`, `QPainter`, `SmoothPixmapTransform`
+
+### 3. rendering/overlay.py
+
+```python
+font = QFont("monospace", 11)  # zamiast "Consolas"
+```
+
+Dodatkowo: obsługa błędu w `paintEvent`:
+- Jeśli `self._metrics` ma klucz `"error"` → pomiń normalne metryki, narysuj czerwony komunikat błędu
+- Użyj `QColor(180, 40, 40)` zamiast zielonego
+
+### 4. app.py — nowe DI wiring
+
+```python
+def main():
+    app = QApplication(sys.argv)
+    app.setApplicationName("Duck Preview")
+
+    camera = CameraService()
+    video_sink = QVideoSink()
+    dispatcher = FrameDispatcher()
+    telemetry = TelemetryCollector()
+    video_widget = VideoWidget()
+    overlay = OverlayWidget()
+
+    camera.set_video_widget(video_widget)
+    camera.set_video_sink(video_sink)
+
+    video_sink.videoFrameChanged.connect(dispatcher.on_frame)
+    dispatcher.subscribe(telemetry.on_frame)
+
+    window = MainWindow(camera, video_widget, overlay)
+
+    # Wire error → overlay
+    camera.error_occurred.connect(
+        lambda msg: overlay.set_metrics({"error": msg})
+    )
+
+    # Poll telemetry → overlay
+    metrics_timer = QTimer()
+    metrics_timer.timeout.connect(
+        lambda: overlay.set_metrics(telemetry.metrics())
+    )
+    metrics_timer.start(200)
+
+    window.show()
+    sys.exit(app.exec())
+```
+
+Zmiany:
+- Tworzy `QVideoSink` jawnie
+- `camera.set_video_widget(video_widget)` + `camera.set_video_sink(video_sink)`
+- `video_sink.videoFrameChanged → dispatcher.on_frame`
+- Usunięto `camera.sink` (property nie istnieje)
+- `camera.error_occurred → overlay.set_metrics({"error": msg})`
+
+### 5. main_window.py — permission flow
+
+```python
+# Importy
+from PySide6.QtCore import QCameraPermission, Qt
+from PySide6.QtWidgets import QApplication
+
+# W _on_camera_selected:
+def _on_camera_selected(self, device: QCameraDevice) -> None:
+    self._request_camera_permission(device)
+
+def _request_camera_permission(self, device: QCameraDevice) -> None:
+    perm = QCameraPermission()
+    match QApplication.checkPermission(perm):
+        case Qt.PermissionStatus.Undetermined:
+            QApplication.requestPermission(perm, self,
+                lambda: self._request_camera_permission(device))
+        case Qt.PermissionStatus.Denied:
+            self._overlay.set_metrics({
+                "error": "Camera permission denied.\n"
+                         "Grant access in System Settings > "
+                         "Privacy & Security > Camera"
+            })
+        case Qt.PermissionStatus.Granted:
+            self._camera.start(device)
+            self._rebuild_resolution_menu(device)
+```
+
+### 6. pyside6-deploy.toml
+
+```toml
+[app]
+script = "duck_preview/__main__.py"
+name = "Duck Preview"
+bundle_identifier = "com.bartool.duck-preview"
+categories = "public.app-category.photography"
+platforms = ["macos"]
+```
+
+### 7. Po zmianach
+
+- `ruff check .` — czysty
+- `ruff format .` — sformatowany
+- `pytest -q` — 5 passed
+
+---
+
+## Podsumowanie architektury końcowej
+
+```
+CameraService
+  ├─ session.setVideoOutput(VideoWidget)   → natywne GPU rendering
+  └─ session.setVideoSink(VideoSink)       → frame access
+                                              └─ videoFrameChanged
+                                                   → FrameDispatcher
+                                                        ├─ TelemetryCollector
+                                                        └─ [future AI]
+
+MainWindow
+  ├─ _on_camera_selected
+  │    → QCameraPermission check (Undetermined/Denied/Granted)
+  │    → CameraService.start(device)
+  ├─ error_occurred → OverlayWidget.set_metrics({"error": ...})
+  └─ QTimer 200ms → TelemetryCollector.metrics() → OverlayWidget
+
+OverlayWidget
+  ├─ normal: zielone metryki (FPS, frame time, frame count)
+  └─ error: czerwony komunikat (np. brak permisji)
+```

notes/02-mvp-mac.md

@@ -0,0 +1,126 @@
+# macOS — Camera on macOS with PySide6
+
+## Problem
+
+Aplikacja uruchomiona w interpreted mode (`python -m duck_preview`) na macOS z kamerą Elgato nie wyświetla obrazu.
+
+## Przyczyna
+
+Oficjalny przykład PySide6 (`camera.qml` / examples/multimedia) zawiera kod:
+
+```python
+if sys.platform == "darwin":
+    is_nuitka = "__compiled__" in globals()
+    if not is_nuitka and sys.platform == "darwin":
+        print("This example does not work on macOS when Python is run "
+              "in interpreted mode. For this example to work on macOS, "
+              "package the example using pyside6-deploy")
+        sys.exit(0)
+```
+
+**macOS → AVFoundation → wymaga spakowania przez Nuitka/pyside6-deploy.**
+
+`QCamera` na macOS potrzebuje properly bundled app structure (Info.plist, entitlements, code signing). W interpreted mode Python nie ma tego contextu.
+
+## Rozwiązanie
+
+Pakować aplikację przez `pyside6-deploy` (Nuitka) na macOS. Na Windows działa bez pakowania.
+
+---
+
+## Qt Permission API (`QCameraPermission`)
+
+Od Qt 6.5+ dostępne jest `QCameraPermission` — nowoczesne API do proszenia o zgodę kamery.
+
+### API
+
+```python
+from PySide6.QtCore import QCameraPermission, Qt
+from PySide6.QtWidgets import QApplication
+
+perm = QCameraPermission()
+match QApplication.checkPermission(perm):
+    case Qt.PermissionStatus.Undetermined:
+        # Prosimy o zgodę → callback wywoła init ponownie
+        QApplication.requestPermission(perm, parent, callback)
+        return
+    case Qt.PermissionStatus.Denied:
+        # overlay: "Camera permission denied"
+    case Qt.PermissionStatus.Granted:
+        # uruchom kamerę
+```
+
+### Permission flow
+
+```
+User → wybiera kamerę w menu
+  → MainWindow._on_camera_selected(device)
+    → checkPermission(QCameraPermission)
+      ├─ Undetermined → requestPermission(camera, parent, callback)
+      │                   └─ callback → _on_camera_selected ponownie
+      ├─ Denied → overlay: "Camera permission denied. Grant access in System Settings > Privacy & Security > Camera"
+      └─ Granted → CameraService.start(device)
+```
+
+---
+
+## QVideoWidget + QVideoSink — dual output
+
+PySide6 6.11 ma osobne metody w `QMediaCaptureSession`:
+
+| Metoda | Przeznaczenie |
+|--------|---------------|
+| `setVideoOutput(QVideoWidget*)` | Natywne renderowanie (GPU) |
+| `setVideoSink(QVideoSink*)` | Dostęp do klatek (telemetria, AI) |
+
+Oba działają **równolegle** — nie ma konfliktu.
+
+```
+QMediaCaptureSession
+  ├─ setVideoOutput(QVideoWidget)  → natywne renderowanie
+  └─ setVideoSink(QVideoSink)      → frame access
+                                       └─ videoFrameChanged → FrameDispatcher
+```
+
+QVideoSink dostarcza sygnał `videoFrameChanged(QVideoFrame)` — na to podpina się FrameDispatcher, a ten rozsyła do TelemetryCollector i przyszłych AI subscriberów.
+
+---
+
+## macOS — packaging
+
+### pyside6-deploy
+
+```bash
+pip install nuitka
+pyside6-deploy duck_preview/__main__.py --name "Duck Preview"
+```
+
+### pyside6-deploy.toml
+
+```toml
+[app]
+script = "duck_preview/__main__.py"
+name = "Duck Preview"
+bundle_identifier = "com.bartool.duck-preview"
+categories = "public.app-category.photography"
+platforms = ["macos"]
+```
+
+Po spakowaniu powstaje `Duck Preview.app` — standalone bundle z dostępem do AVFoundation.
+
+### Windows
+
+Na Windows działa bez pakowania — `python -m duck_preview` w venv.
+
+---
+
+## Font fallback
+
+`Consolas` nie istnieje na macOS. Używać `"monospace"` (generic font family — Qt mapuje na Menlo na macOS, Consolas na Windows).
+
+## Error state w Overlay
+
+Overlay wspiera wyświetlanie błędów (np. brak permisji):
+- Normalny stan → zielone metryki (FPS, frame times)
+- Error state → czerwony komunikat
+- Przełączanie przez `overlay.set_metrics({"error": "message"})`

pyside6-deploy.toml

@@ -0,0 +1,6 @@
+[app]
+script = "duck_preview/__main__.py"
+name = "Duck Preview"
+bundle_identifier = "com.bartool.duck-preview"
+categories = "public.app-category.photography"
+platforms = ["macos"]