win32: Use AUTOCONVERTPCM when initializing the audio client.

Right now, on Wine, IsFormatSupported() advertises every
(extensible) format as supported, and correspondingly Initialize()
accepts every (extensible) format. However that behavior is not
what happen on Windows, where both IsFormatSupported() and
Initialize() rejects format the differ from the current mmdevapi
mix format for anything other than the sample format.

This might be rectified at some point in Wine. To maintain the
current behavior in FAudio, we stop querying with
IsFormatSupported() and pass flag AUTOCONVERTPCM to Initialize().

Author: giomasce

src/FAudio_platform_win32.c

@@ -352,7 +352,6 @@ void FAudio_PlatformInit(
 	struct FAudioAudioClientThreadArgs *args;
 	struct FAudioWin32PlatformData *data;
 	REFERENCE_TIME duration;
-	WAVEFORMATEX *closest;
 	IMMDevice *device = NULL;
 	HRESULT hr;
 	HANDLE audioEvent = NULL;
@@ -419,25 +418,10 @@ void FAudio_PlatformInit(
 	if (flags & FAUDIO_1024_QUANTUM) duration = 213333;
 	else duration = 100000;
 
-	hr = IAudioClient_IsFormatSupported(
-		data->client,
-		AUDCLNT_SHAREMODE_SHARED,
-		&args->format.Format,
-		&closest
-	);
-	FAudio_assert(!FAILED(hr) && "Failed to find supported audio format!");
-
-	if (closest)
-	{
-		if (closest->wFormatTag != WAVE_FORMAT_EXTENSIBLE) args->format.Format = *closest;
-		else args->format = *(WAVEFORMATEXTENSIBLE *)closest;
-		CoTaskMemFree(closest);
-	}
-
 	hr = IAudioClient_Initialize(
 		data->client,
 		AUDCLNT_SHAREMODE_SHARED,
-		AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
+		AUDCLNT_STREAMFLAGS_EVENTCALLBACK | AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM,
 		duration * 3,
 		0,
 		&args->format.Format,