winmm: Try to get full device names from the Windows Registry.

src/audio/winmm/SDL_winmm.c

@@ -37,8 +37,7 @@
 #define WAVE_FORMAT_IEEE_FLOAT 0x0003
 #endif
 
-/* !!! FIXME:
+/*
-
 WAVExxxCAPS gives you 31 bytes for the device name, and just truncates if it's
 longer. However, since WinXP, you can use the WAVExxxCAPS2 structure, which
 will give you a name GUID. The full name is in the Windows Registry under
@@ -50,17 +49,74 @@ This info summarized from MSDN:
 
 http://web.archive.org/web/20131027093034/http://msdn.microsoft.com/en-us/library/windows/hardware/ff536382(v=vs.85).aspx
 
+Always look this up in the registry if possible, because the strings are
+different! At least on Win10, I see "Yeti Stereo Microphone" in the
+Registry, and a unhelpful "Microphone(Yeti Stereo Microph" in winmm. Sigh.
 */
+static char *
+LookupDeviceName(const WCHAR *name, const GUID *guid)
+{
+    static const GUID nullguid = { 0 };
+    const unsigned char *ptr;
+    char keystr[128];
+    WCHAR *strw = NULL;
+    SDL_bool rc;
+    HKEY hkey;
+    DWORD len = 0;
+    char *retval = NULL;
+
+    if (SDL_memcmp(guid, &nullguid, sizeof (*guid)) == 0) {
+        return WIN_StringToUTF8(name);  /* No GUID, go with what we've got. */
+    }
+
+    ptr = (const char *) guid;
+    SDL_snprintf(keystr, sizeof (keystr),
+        "System\\CurrentControlSet\\Control\\MediaCategories\\{%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
+        ptr[3], ptr[2], ptr[1], ptr[0], ptr[5], ptr[4], ptr[7], ptr[6],
+        ptr[8], ptr[9], ptr[10], ptr[11], ptr[12], ptr[13], ptr[14], ptr[15]);
+
+    strw = WIN_UTF8ToString(keystr);
+    rc = (RegOpenKeyExW(HKEY_LOCAL_MACHINE, strw, 0, KEY_QUERY_VALUE, &hkey) == ERROR_SUCCESS);
+    SDL_free(strw);
+    if (!rc) {
+        return WIN_StringToUTF8(name);  /* oh well. */
+    }
+
+    rc = (RegQueryValueExW(hkey, L"Name", NULL, NULL, NULL, &len) == ERROR_SUCCESS);
+    if (!rc) {
+        RegCloseKey(hkey);
+        return WIN_StringToUTF8(name);  /* oh well. */
+    }
+
+    strw = (WCHAR *) SDL_malloc(len + sizeof (WCHAR));
+    if (!strw) {
+        RegCloseKey(hkey);
+        return WIN_StringToUTF8(name);  /* oh well. */
+    }
+
+    rc = (RegQueryValueExW(hkey, L"Name", NULL, NULL, (LPBYTE) strw, &len) == ERROR_SUCCESS);
+    RegCloseKey(hkey);
+    if (!rc) {
+        SDL_free(strw);
+        return WIN_StringToUTF8(name);  /* oh well. */
+    }
+
+    strw[len / 2] = 0;  /* make sure it's null-terminated. */
+
+    retval = WIN_StringToUTF8(strw);
+    SDL_free(strw);
+    return retval ? retval : WIN_StringToUTF8(name);
+}
 
 #define DETECT_DEV_IMPL(iscap, typ, capstyp) \
 static void DetectWave##typ##Devs(void) { \
     const UINT iscapture = iscap ? 1 : 0; \
     const UINT devcount = wave##typ##GetNumDevs(); \
-    capstyp caps; \
+    capstyp##2W caps; \
     UINT i; \
     for (i = 0; i < devcount; i++) { \
-        if (wave##typ##GetDevCaps(i,&caps,sizeof(caps))==MMSYSERR_NOERROR) { \
+	if (wave##typ##GetDevCaps(i,(LP##capstyp##W)&caps,sizeof(caps))==MMSYSERR_NOERROR) { \
-            char *name = WIN_StringToUTF8(caps.szPname); \
+            char *name = LookupDeviceName(caps.szPname,&caps.NameGuid); \
             if (name != NULL) { \
                 SDL_AddAudioDevice((int) iscapture, name, (void *) ((size_t) i+1)); \
                 SDL_free(name); \