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diff --git a/sound/mods/paula.h b/sound/mods/paula.h
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+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2007 The ScummVM project
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef SOUND_MODS_PAULA_H
+#define SOUND_MODS_PAULA_H
+
+#include "sound/audiostream.h"
+#include "common/mutex.h"
+
+namespace Audio {
+
+/**
+ * Emulation of the "Paula" Amiga music chip
+ * The interrupt frequency specifies the number of mixed wavesamples between
+ * calls of the interrupt method
+ */
+class Paula : public AudioStream {
+public:
+	Paula(bool stereo = false, int rate = 44100, int interruptFreq = 0);
+	~Paula();
+	
+	bool playing() const { return _playing; }
+	void setInterruptFreq(int freq) { _intFreq = freq; }
+	void setPanning(byte voice, byte panning)
+	{
+		if (voice < 4)
+			_voice[voice].panning = panning;
+	}
+	void clearVoice(byte voice);
+	void clearVoices() { int i; for (i = 0; i < 4; i++) clearVoice(i); }
+	virtual void startPlay(void) {}
+	virtual void stopPlay(void) {}
+	virtual void pausePlay(bool pause) {}
+
+// AudioStream API
+	int readBuffer(int16 *buffer, const int numSamples);
+	bool isStereo() const { return _stereo; }
+	bool endOfData() const { return _end; }
+	int getRate() const { return _rate; }
+
+protected:
+	struct Channel {
+		int8 *data;
+		int8 *dataRepeat;
+		uint32 length;
+		uint32 lengthRepeat;
+		int16 period;
+		byte volume;
+		double offset;
+		byte panning; // For stereo mixing: 0 = far left, 255 = far right
+	} _voice[4];
+
+	int _rate;
+	int _intFreq;
+	int _curInt;
+	bool _stereo;
+	bool _end;
+	bool _playing;
+	Common::Mutex _mutex;
+
+	void mix(int16 *&buf, int8 data, int voice) {
+		if (_stereo) {
+			*buf++ += (((int32) data) * _voice[voice].volume *
+				 (255 - _voice[voice].panning)) >> 7;
+			*buf++ += (((int32) data) * _voice[voice].volume *
+				 (_voice[voice].panning)) >> 7;
+		} else
+			*buf++ += _voice[voice].volume * data;
+	}
+	virtual void interrupt(void) {};
+};
+
+} // End of namespace Audio
+
+#endif