Update XAudio driver to use floating point. Nits here and there.

audio/xaudio-c/xaudio-c.cpp

@@ -11,26 +11,26 @@
 
 struct xaudio2 : public IXAudio2VoiceCallback
 {
-	xaudio2(unsigned samplerate, unsigned channels, unsigned bits, unsigned size) : 
+   xaudio2(unsigned samplerate, unsigned channels, unsigned size) : 
       buf(0), pXAudio2(0), pMasterVoice(0), pSourceVoice(0),
       buffers(0), bufptr(0)
    {
       CoInitializeEx(0, COINIT_MULTITHREADED);
-		HRESULT hr;
+      if (FAILED(XAudio2Create(&pXAudio2, 0)))
-		if (FAILED(hr = XAudio2Create(&pXAudio2, 0)))
          throw -1;
-		if (FAILED(hr = pXAudio2->CreateMasteringVoice(
+      if (FAILED(pXAudio2->CreateMasteringVoice(
                   &pMasterVoice, channels, samplerate, 0, 0, 0)))
          throw -1;
+
       WAVEFORMATEX wfx;
-		wfx.wFormatTag = WAVE_FORMAT_PCM;
+      wfx.wFormatTag = WAVE_FORMAT_IEEE_FLOAT;
       wfx.nChannels = channels;
       wfx.nSamplesPerSec = samplerate;
-		wfx.nBlockAlign = channels * bits / 8;
+      wfx.nBlockAlign = channels * sizeof(float);
-		wfx.wBitsPerSample = bits;
+      wfx.wBitsPerSample = sizeof(float) * 8;
       wfx.nAvgBytesPerSec = wfx.nSamplesPerSec * wfx.nBlockAlign;
       wfx.cbSize = 0;
-		if (FAILED(hr = pXAudio2->CreateSourceVoice(
+      if (FAILED(pXAudio2->CreateSourceVoice(
                   &pSourceVoice, &wfx, XAUDIO2_VOICE_NOSRC, XAUDIO2_DEFAULT_FREQ_RATIO, this, 0, 0)))
          throw -1;
 
@@ -40,7 +40,6 @@ struct xaudio2 : public IXAudio2VoiceCallback
 
       pSourceVoice->Start(0);
 
-		max_buffers = 8;
       bufsize = size / max_buffers;
       buf = new uint8_t[bufsize * max_buffers];
       write_buffer = 0;
@@ -72,34 +71,44 @@ struct xaudio2 : public IXAudio2VoiceCallback
       return bufsize * (max_buffers - buffers - 1);
    }
 
-	size_t write(const void *buffer, size_t bytes)
+   size_t write(const void *buffer_, size_t bytes_)
    {
-		size_t written = 0;
+      unsigned bytes = bytes_;
-		while (written < bytes)
+      const uint8_t *buffer = reinterpret_cast<const uint8_t*>(buffer_);
+      while (bytes > 0)
       {
-			size_t need = std::min(bytes - written, static_cast<size_t>(bufsize - bufptr));
+         unsigned need = std::min(bytes, bufsize - bufptr);
-			memcpy(buf + write_buffer * bufsize + bufptr, (const uint8_t*)buffer + written, need);
+         memcpy(buf + write_buffer * bufsize + bufptr,
-			written += need;
+               buffer, need);
+
          bufptr += need;
+         buffer += need;
+         bytes -= need;
 
          if (bufptr == bufsize)
          {
-				while (static_cast<volatile unsigned>(buffers) == max_buffers - 1)
+            WaitForSingleObject(hEvent, 0); // Clear out ready state.
+            while (buffers == max_buffers - 1)
                WaitForSingleObject(hEvent, INFINITE);
 
             XAUDIO2_BUFFER xa2buffer = {0};
             xa2buffer.AudioBytes = bufsize;
             xa2buffer.pAudioData = buf + write_buffer * bufsize;
             xa2buffer.pContext = 0;
+            if (FAILED(pSourceVoice->SubmitSourceBuffer(&xa2buffer)))
+               return 0;
+
             InterlockedIncrement(&buffers);
-				pSourceVoice->SubmitSourceBuffer(&xa2buffer);
             bufptr = 0;
-				write_buffer = (write_buffer + 1) % max_buffers;
+            write_buffer = (write_buffer + 1) & (max_buffers_mask);
          }
       }
-		return bytes;
+
+      return bytes_;
    }
 
+   enum { max_buffers = 16, max_buffers_mask = max_buffers - 1 };
+
    STDMETHOD_(void, OnBufferStart) (void *) {}
    STDMETHOD_(void, OnBufferEnd) (void *) 
    {
@@ -109,10 +118,7 @@ struct xaudio2 : public IXAudio2VoiceCallback
    STDMETHOD_(void, OnLoopEnd) (void *) {}
    STDMETHOD_(void, OnStreamEnd) () {}
    STDMETHOD_(void, OnVoiceError) (void *, HRESULT) {}
-	STDMETHOD_(void, OnVoiceProcessingPassEnd) () 
+   STDMETHOD_(void, OnVoiceProcessingPassEnd) () {}
-	{
-		SetEvent(hEvent);
-	}
    STDMETHOD_(void, OnVoiceProcessingPassStart) (UINT32) {}
 
    uint8_t *buf;
@@ -122,17 +128,16 @@ struct xaudio2 : public IXAudio2VoiceCallback
    HANDLE hEvent;
 
    volatile long buffers;
-	unsigned max_buffers;
    unsigned bufsize;
    unsigned bufptr;
    unsigned write_buffer;
 };
 
-xaudio2_t *xaudio2_new(unsigned samplerate, unsigned channels, unsigned bits, size_t size)
+xaudio2_t *xaudio2_new(unsigned samplerate, unsigned channels, size_t size)
 {
    xaudio2 *handle = 0;
    try {
-		handle = new xaudio2(samplerate, channels, bits, size);
+      handle = new xaudio2(samplerate, channels, size);
    } catch(...) { delete handle; return 0; }
 
    return handle;

audio/xaudio-c/xaudio-c.h

@@ -15,7 +15,7 @@ extern "C" {
 
 typedef struct xaudio2 xaudio2_t;
 
-xaudio2_t* xaudio2_new(unsigned samplerate, unsigned channels, unsigned bits, size_t bufsize);
+xaudio2_t* xaudio2_new(unsigned samplerate, unsigned channels, size_t bufsize);
 size_t xaudio2_write_avail(xaudio2_t *handle);
 size_t xaudio2_write(xaudio2_t *handle, const void *data, size_t bytes);
 void xaudio2_free(xaudio2_t *handle);

audio/xaudio.c

@@ -36,11 +36,10 @@ static void* __xa_init(const char* device, unsigned rate, unsigned latency)
       return NULL;
 
    size_t bufsize = latency * rate / 1000;
-   bufsize = next_pow2(bufsize);
 
    SSNES_LOG("XAudio2: Requesting %d ms latency, using %d ms latency.\n", latency, (int)bufsize * 1000 / rate);
 
-   xa->xa = xaudio2_new(rate, 2, 16, bufsize << 2);
+   xa->xa = xaudio2_new(rate, 2, bufsize * 2 * sizeof(float));
    if (!xa->xa)
    {
       SSNES_ERR("Failed to init XAudio2.\n");
@@ -56,10 +55,15 @@ static ssize_t __xa_write(void* data, const void* buf, size_t size)
    if (xa->nonblock)
    {
       size_t avail = xaudio2_write_avail(xa->xa);
+      if (avail == 0)
+         return 0;
       if (avail < size)
          size = avail;
    }
-   return xaudio2_write(xa->xa, buf, size);
+   size_t ret = xaudio2_write(xa->xa, buf, size);
+   if (ret == 0)
+      return -1;
+   return ret;
 }
 
 static bool __xa_stop(void *data)
@@ -80,6 +84,12 @@ static bool __xa_start(void *data)
    return true;
 }
 
+static bool __xa_use_float(void *data)
+{
+   (void)data;
+   return true;
+}
+
 static void __xa_free(void *data)
 {
    xa_t *xa = data;
@@ -97,6 +107,7 @@ const audio_driver_t audio_xa = {
    .stop = __xa_stop,
    .start = __xa_start,
    .set_nonblock_state = __xa_set_nonblock_state,
+   .use_float = __xa_use_float,
    .free = __xa_free,
    .ident = "xaudio"
 };