Fix compile with MSVC

src/engine/directsounddevicefinder.h

@@ -40,10 +40,12 @@ class DirectSoundDeviceFinder : public DeviceFinder {
     QList<Device> devices;
   };
 
-  static BOOL EnumerateCallback(LPGUID guid,
-                                LPCSTR description,
-                                LPCSTR module,
-                                LPVOID state_voidptr) __attribute__((stdcall));
+  static BOOL EnumerateCallback(LPGUID guid, LPCSTR description, LPCSTR module, LPVOID state_voidptr)
+#ifdef _MSC_VER
+    ;
+#else
+    __attribute__((stdcall));
+#endif
 };
 
 #endif  // DIRECTSOUNDDEVICEFINDER_H

src/engine/gstengine.cpp

@@ -875,7 +875,7 @@ void GstEngine::UpdateScope(const int chunk_length) {
   sample_type *dest = scope_.data();
   source += (chunk_size / sizeof(sample_type)) * scope_chunk_;
 
-  int bytes = 0;
+  size_t bytes = 0;
 
   // Make sure we don't go beyond the end of the buffer
   if (scope_chunk_ == scope_chunks_ - 1) {

src/engine/mmdevicefinder.cpp

@@ -22,7 +22,11 @@
 #include <windows.h>
 #include <initguid.h>
 #include <devpkey.h>
-#include <functiondiscoverykeys_devpkey.h>
+#ifdef _MSC_VER
+#  include <functiondiscoverykeys.h>
+#else
+#  include <functiondiscoverykeys_devpkey.h>
+#endif
 #include <mmdeviceapi.h>
 
 #include <QList>
@@ -32,6 +36,11 @@
 #include "mmdevicefinder.h"
 #include "core/logging.h"
 
+#ifdef _MSC_VER
+  DEFINE_GUID(IID_IMMDeviceEnumerator, 0xa95664d2, 0x9614, 0x4f35, 0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6);
+  DEFINE_GUID(CLSID_MMDeviceEnumerator, 0xbcde0395, 0xe52f, 0x467c, 0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e);
+#endif
+
 MMDeviceFinder::MMDeviceFinder() : DeviceFinder("mmdevice", { "wasapisink" }) {}
 
 QList<DeviceFinder::Device> MMDeviceFinder::ListDevices() {