diff -r 93b982ccede2 -r 5daf16870df6 src/multimedia/audio/qaudiooutput_win32_p.cpp
--- a/src/multimedia/audio/qaudiooutput_win32_p.cpp	Mon Jun 21 22:38:13 2010 +0100
+++ b/src/multimedia/audio/qaudiooutput_win32_p.cpp	Thu Jul 22 16:41:55 2010 +0100
@@ -56,8 +56,6 @@
 
 QT_BEGIN_NAMESPACE
 
-static const int minimumIntervalTime = 50;
-
 QAudioOutputPrivate::QAudioOutputPrivate(const QByteArray &device, const QAudioFormat& audioFormat):
     settings(audioFormat)
 {
@@ -73,17 +71,15 @@
     audioSource = 0;
     pullMode = true;
     finished = false;
-    InitializeCriticalSection(&waveOutCriticalSection);
 }
 
 QAudioOutputPrivate::~QAudioOutputPrivate()
 {
-    EnterCriticalSection(&waveOutCriticalSection);
+    mutex.lock();
     finished = true;
-    LeaveCriticalSection(&waveOutCriticalSection);
+    mutex.unlock();
 
     close();
-    DeleteCriticalSection(&waveOutCriticalSection);
 }
 
 void CALLBACK QAudioOutputPrivate::waveOutProc( HWAVEOUT hWaveOut, UINT uMsg,
@@ -98,6 +94,8 @@
     if(!qAudio)
         return;
 
+    QMutexLocker(&qAudio->mutex);
+
     switch(uMsg) {
         case WOM_OPEN:
             qAudio->feedback();
@@ -105,16 +103,13 @@
         case WOM_CLOSE:
             return;
         case WOM_DONE:
-            EnterCriticalSection(&qAudio->waveOutCriticalSection);
             if(qAudio->finished || qAudio->buffer_size == 0 || qAudio->period_size == 0) {
-                LeaveCriticalSection(&qAudio->waveOutCriticalSection);
                 return;
 	    }
             qAudio->waveFreeBlockCount++;
             if(qAudio->waveFreeBlockCount >= qAudio->buffer_size/qAudio->period_size)
                 qAudio->waveFreeBlockCount = qAudio->buffer_size/qAudio->period_size;
             qAudio->feedback();
-            LeaveCriticalSection(&qAudio->waveOutCriticalSection);
             break;
         default:
             return;
@@ -150,7 +145,7 @@
     int count = buffer_size/period_size;
 
     for(int i = 0; i < count; i++) {
-        waveOutUnprepareHeader(hWaveOut,&blocks[i], sizeof(WAVEHDR));
+        waveOutUnprepareHeader(hWaveOut,blocks, sizeof(WAVEHDR));
         blocks+=sizeof(WAVEHDR);
     }
     HeapFree(GetProcessHeap(), 0, blockArray);
@@ -225,9 +220,9 @@
     }
     waveBlocks = allocateBlocks(period_size, buffer_size/period_size);
 
-    EnterCriticalSection(&waveOutCriticalSection);
+    mutex.lock();
     waveFreeBlockCount = buffer_size/period_size;
-    LeaveCriticalSection(&waveOutCriticalSection);
+    mutex.unlock();
 
     waveCurrentBlock = 0;
 
@@ -255,7 +250,7 @@
         if(waveOutGetDevCaps(ii, &woc, sizeof(WAVEOUTCAPS))
 	    == MMSYSERR_NOERROR) {
 	    QString tmp;
-	    tmp = QString::fromUtf16((const unsigned short*)woc.szPname);
+	    tmp = QString((const QChar *)woc.szPname);
             if(tmp.compare(QLatin1String(m_device)) == 0) {
 	        devId = ii;
 		break;
@@ -333,10 +328,7 @@
 
 void QAudioOutputPrivate::setNotifyInterval(int ms)
 {
-    if(ms >= minimumIntervalTime)
-        intervalTime = ms;
-    else
-        intervalTime = minimumIntervalTime;
+    intervalTime = qMax(0, ms);
 }
 
 int QAudioOutputPrivate::notifyInterval() const
@@ -368,12 +360,12 @@
     int remain;
     current = &waveBlocks[waveCurrentBlock];
     while(l > 0) {
-        EnterCriticalSection(&waveOutCriticalSection);
+        mutex.lock();
         if(waveFreeBlockCount==0) {
-            LeaveCriticalSection(&waveOutCriticalSection);
+            mutex.unlock();
             break;
         }
-        LeaveCriticalSection(&waveOutCriticalSection);
+        mutex.unlock();
 
         if(current->dwFlags & WHDR_PREPARED)
             waveOutUnprepareHeader(hWaveOut, current, sizeof(WAVEHDR));
@@ -390,15 +382,13 @@
         waveOutPrepareHeader(hWaveOut, current, sizeof(WAVEHDR));
         waveOutWrite(hWaveOut, current, sizeof(WAVEHDR));
 
-        EnterCriticalSection(&waveOutCriticalSection);
+        mutex.lock();
         waveFreeBlockCount--;
-        LeaveCriticalSection(&waveOutCriticalSection);
 #ifdef DEBUG_AUDIO
-        EnterCriticalSection(&waveOutCriticalSection);
         qDebug("write out l=%d, waveFreeBlockCount=%d",
                 current->dwBufferLength,waveFreeBlockCount);
-        LeaveCriticalSection(&waveOutCriticalSection);
 #endif
+        mutex.unlock();
         totalTimeValue += current->dwBufferLength;
         waveCurrentBlock++;
         waveCurrentBlock %= buffer_size/period_size;
@@ -453,7 +443,7 @@
 
 bool QAudioOutputPrivate::deviceReady()
 {
-    if(deviceState == QAudio::StoppedState)
+    if(deviceState == QAudio::StoppedState || deviceState == QAudio::SuspendedState)
         return false;
 
     if(pullMode) {
@@ -467,14 +457,16 @@
 	    startup = true;
 
 	bool full=false;
-	EnterCriticalSection(&waveOutCriticalSection);
+
+        mutex.lock();
 	if(waveFreeBlockCount==0) full = true;
-	LeaveCriticalSection(&waveOutCriticalSection);
+        mutex.unlock();
+
 	if (full){
 #ifdef DEBUG_AUDIO
             qDebug() << "Skipping data as unable to write";
 #endif
-	    if((timeStamp.elapsed() + elapsedTimeOffset) > intervalTime ) {
+	    if(intervalTime && (timeStamp.elapsed() + elapsedTimeOffset) > intervalTime ) {
                 emit notify();
 		elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
 		timeStamp.restart();
@@ -504,12 +496,14 @@
             bytesAvailable = bytesFree();
 
             int check = 0;
-            EnterCriticalSection(&waveOutCriticalSection);
+
+            mutex.lock();
             check = waveFreeBlockCount;
-            LeaveCriticalSection(&waveOutCriticalSection);
+            mutex.unlock();
+
             if(check == buffer_size/period_size) {
-                errorState = QAudio::UnderrunError;
                 if (deviceState != QAudio::IdleState) {
+                    errorState = QAudio::UnderrunError;
                     deviceState = QAudio::IdleState;
                     emit stateChanged(deviceState);
                 }
@@ -521,19 +515,23 @@
         }
     } else {
         int buffered;
-	EnterCriticalSection(&waveOutCriticalSection);
+
+        mutex.lock();
 	buffered = waveFreeBlockCount;
-	LeaveCriticalSection(&waveOutCriticalSection);
-        errorState = QAudio::UnderrunError;
+        mutex.unlock();
+
         if (buffered >= buffer_size/period_size && deviceState == QAudio::ActiveState) {
-            deviceState = QAudio::IdleState;
-            emit stateChanged(deviceState);
+            if (deviceState != QAudio::IdleState) {
+                errorState = QAudio::UnderrunError;
+                deviceState = QAudio::IdleState;
+                emit stateChanged(deviceState);
+            }
         }
     }
     if(deviceState != QAudio::ActiveState && deviceState != QAudio::IdleState)
         return true;
 
-    if((timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
+    if(intervalTime && (timeStamp.elapsed() + elapsedTimeOffset) > intervalTime) {
         emit notify();
 	elapsedTimeOffset = timeStamp.elapsed() + elapsedTimeOffset - intervalTime;
         timeStamp.restart();