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diff --git a/arm-wt-22k/lib_src/eas_pan.h b/arm-wt-22k/lib_src/eas_pan.h
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+/*----------------------------------------------------------------------------
+ *
+ * File: 
+ * eas_pan.h
+ *
+ * Contents and purpose:
+ * Calculates left and right gain multipliers based on a pan value from -63 to +63
+ *
+ * NOTES:
+ * The _CMX_PARSER and _MFI_PARSER preprocessor symbols determine
+ * whether the parser works for those particular file formats. 
+ *
+ * Copyright Sonic Network Inc. 2005
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ *----------------------------------------------------------------------------
+ * Revision Control:
+ *   $Revision: 82 $
+ *   $Date: 2006-07-10 11:45:19 -0700 (Mon, 10 Jul 2006) $
+ *----------------------------------------------------------------------------
+*/
+
+#ifndef EAS_PAN_H
+#define _EAS_PAN_H
+
+#include "eas_types.h"
+
+/*----------------------------------------------------------------------------
+ * EAS_CalcPanControl()
+ *----------------------------------------------------------------------------
+ * Purpose: 
+ * Assign the left and right gain values corresponding to the given pan value.
+ *
+ * This routine uses sin/cos approximations for an equal power curve:
+ * 
+ * sin(x) = (2-4*c)*x^2 + c + x
+ * cos(x) = (2-4*c)*x^2 + c - x
+ *
+ * where  c = 1/sqrt(2)
+ * using the a0 + x*(a1 + x*a2) approach
+ *
+ * Inputs: 
+ * pan			- pan value (-63 to + 63)
+ * 
+ * Outputs:
+ * pGainLeft	linear gain multiplier for left channel (15-bit fraction)
+ * pGainRight	linear gain multiplier for left channel (15-bit fraction)
+ *
+ * Side Effects:
+ *----------------------------------------------------------------------------
+*/
+void EAS_CalcPanControl (EAS_INT pan, EAS_I16 *pGainLeft, EAS_I16 *pGainRight);
+
+#endif
+