Sound hinzugefügt und UI aufgeräumt

include/videowidget.h

@@ -12,6 +12,13 @@
 
 #include "v4l2worker.h"
 
+// A uniform, icon-only push button used for the video toolbar (start/stop,
+// freeze, screenshot, record, fullscreen, audio, ...). All toolbar buttons
+// share the same fixed square size and font so the row lines up neatly
+// instead of every button sizing itself to its own label.
+QPushButton *makeToolbarIconButton(const QString &symbol, const QString &tooltip,
+                                   QWidget *parent);
+
 // A borderless top-level window that mirrors the live video frame at full
 // screen size. Opened from VideoWidget's "⛶" button; closes itself on
 // Escape or a double-click anywhere on it.
@@ -59,6 +66,14 @@ public:
     // dropping the request).
     void setAutoScreenshotDir(const QString &dir) { m_autoScreenshotDir = dir; }
 
+    // Folders the manual "Screenshot"/"Record" buttons' save dialogs
+    // default to. Set by MainWindow from persisted settings on startup;
+    // VideoWidget reports back via lastScreenshotDirChanged()/
+    // lastVideoDirChanged() whenever the user picks a new folder so
+    // MainWindow can persist it for next time.
+    void setLastScreenshotDir(const QString &dir) { m_lastScreenshotDir = dir; }
+    void setLastVideoDir(const QString &dir) { m_lastVideoDir = dir; }
+
 public slots:
     void onNewFrame(const QImage &frame);
     void clearFrame();   // blanks the preview (used on ANSI clear-screen)
@@ -76,13 +91,21 @@ signals:
     // firmware-driven triggers.
     void autoScreenshotResult(bool success, const QString &message);
 
+    // Emitted whenever the user successfully saves via the manual
+    // "Screenshot"/"Record" buttons, so MainWindow can persist the folder
+    // for next time (see setLastScreenshotDir()/setLastVideoDir()).
+    void lastScreenshotDirChanged(const QString &dir);
+    void lastVideoDirChanged(const QString &dir);
+
 private slots:
     void onStartStop();
     void onFreeze(bool frozen);
     void onScreenshot();
     void onRecordToggled(bool checked);
     void onFullscreenToggle();
+    void onAudioToggled(bool checked);
     void refreshDeviceList();
+    void refreshAudioDevices();
 
 protected:
     void paintEvent(QPaintEvent *event) override;
@@ -96,6 +119,9 @@ private:
     void startRecording();
     void stopRecording();
     void writeRecordingFrame(const QImage &frame);
+    void startAudio();
+    void stopAudio();
+    static QStringList enumerateAudioDevices();
 
     QThread     *m_thread = nullptr;
     V4l2Worker  *m_worker = nullptr;
@@ -114,6 +140,18 @@ private:
     QPushButton *m_fullscreenBtn = nullptr;
     QLabel      *m_infoLabel     = nullptr;
 
+    // Audio passthrough: plays the grabber's ALSA capture device (e.g. the
+    // "USB Audio" card that accompanies a /dev/videoN HDMI/USB grabber)
+    // straight to the default output, the same way the HDMI viewer does it.
+    // Implemented by shelling out to `ffplay -f alsa -i <device>` with
+    // -nodisp (audio only, no extra window) - same approach as recording,
+    // just piping the other direction (device -> speakers instead of
+    // frames -> file).
+    QComboBox   *m_audioCombo    = nullptr;
+    QPushButton *m_audioBtn      = nullptr;
+    QProcess    *m_audioProcess  = nullptr;
+    bool         m_audioActive   = false;
+
     // Fullscreen overlay window (nullptr when not open). Owns itself via
     // Qt::WA_DeleteOnClose; VideoWidget just tracks whether one currently
     // exists and forwards frames to it while it's open.
@@ -131,4 +169,9 @@ private:
     // Folder for saveAutoScreenshot() ([SCREENSHOT] tag). Set via
     // setAutoScreenshotDir(), persisted/restored by MainWindow.
     QString m_autoScreenshotDir;
+
+    // Folders the manual Screenshot/Record save dialogs default to (see
+    // setLastScreenshotDir()/setLastVideoDir() above).
+    QString m_lastScreenshotDir;
+    QString m_lastVideoDir;
 };