diff -r 000000000000 -r 1918ee327afb src/multimedia/audio/qaudio_mac_p.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/multimedia/audio/qaudio_mac_p.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,144 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtMultimedia module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+
+#ifndef QAUDIO_MAC_P_H
+#define QAUDIO_MAC_P_H
+
+#include <CoreAudio/CoreAudio.h>
+
+#include <QtCore/qdebug.h>
+#include <QtCore/qatomic.h>
+
+#include <QtMultimedia/qaudioformat.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Multimedia)
+
+
+extern QDebug operator<<(QDebug dbg, const QAudioFormat& audioFormat);
+
+extern QAudioFormat toQAudioFormat(const AudioStreamBasicDescription& streamFormat);
+extern AudioStreamBasicDescription toAudioStreamBasicDescription(QAudioFormat const& audioFormat);
+
+class QAudioRingBuffer
+{
+public:
+    typedef QPair<char*, int> Region;
+
+    QAudioRingBuffer(int bufferSize);
+    ~QAudioRingBuffer();
+
+    Region acquireReadRegion(int size)
+    {
+        const int used = m_bufferUsed.fetchAndAddAcquire(0);
+
+        if (used > 0) {
+            const int readSize = qMin(size, qMin(m_bufferSize - m_readPos, used));
+
+            return readSize > 0 ? Region(m_buffer + m_readPos, readSize) : Region(0, 0);
+        }
+
+        return Region(0, 0);
+    }
+
+    void releaseReadRegion(Region const& region)
+    {
+        m_readPos = (m_readPos + region.second) % m_bufferSize;
+
+        m_bufferUsed.fetchAndAddRelease(-region.second);
+    }
+
+    Region acquireWriteRegion(int size)
+    {
+        const int free = m_bufferSize - m_bufferUsed.fetchAndAddAcquire(0);
+
+        if (free > 0) {
+            const int writeSize = qMin(size, qMin(m_bufferSize - m_writePos, free));
+
+            return writeSize > 0 ? Region(m_buffer + m_writePos, writeSize) : Region(0, 0);
+        }
+
+        return Region(0, 0);
+    }
+
+    void releaseWriteRegion(Region const& region)
+    {
+        m_writePos = (m_writePos + region.second) % m_bufferSize;
+
+        m_bufferUsed.fetchAndAddRelease(region.second);
+    }
+
+    int used() const;
+    int free() const;
+    int size() const;
+
+    void reset();
+
+private:
+    int     m_bufferSize;
+    int     m_readPos;
+    int     m_writePos;
+    char*   m_buffer;
+    QAtomicInt  m_bufferUsed;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif  // QAUDIO_MAC_P_H
+
+