Sound für synchrone Wiedergabe geändert

include/audiothread.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <QThread>
+#include <QString>
+#include <atomic>
+
+#include <alsa/asoundlib.h>
+
+// Audio passthrough: captures from the grabber's ALSA device and plays it
+// straight to the default output with small buffers (low latency, so the
+// sound stays in sync with the video preview). Same implementation as in
+// the HDMI viewer.
+class AudioThread : public QThread
+{
+    Q_OBJECT
+
+public:
+    explicit AudioThread(const QString &device, QObject *parent = nullptr);
+    ~AudioThread() override;
+
+    void stop();
+
+signals:
+    void errorOccurred(const QString &message);
+
+protected:
+    void run() override;
+
+private:
+    QString           m_device;
+    std::atomic<bool> m_running{false};
+
+    // PCM parameters
+    static constexpr unsigned int      k_defaultRate     = 48000;
+    static constexpr unsigned int      k_defaultChannels = 2;
+    static constexpr snd_pcm_uframes_t k_periodFrames    = 1024;
+};