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+/* ------------------------------------------------------------------
+ * Copyright (C) 1998-2009 PacketVideo
+ *
+ * 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.
+ * -------------------------------------------------------------------
+ */
+/****************************************************************************************
+Portions of this file are derived from the following 3GPP standard:
+
+ 3GPP TS 26.073
+ ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
+ Available from http://www.3gpp.org
+
+(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
+Permission to distribute, modify and use this file under the standard license
+terms listed above has been obtained from the copyright holder.
+****************************************************************************************/
+/*
+
+ Filename: /audio/gsm_amr/c/src/round.c
+
+------------------------------------------------------------------------------
+ REVISION HISTORY
+
+ Description: Created separate file for the round function. Sync'ed up
+ with the current template and fixed tabs.
+
+ Description: Made changes based on review meeting:
+ 1. Removed long in Inputs Definitions.
+ 2. Changed L_var1 to var_out and description in
+ Output Definitions.
+
+ Description: Added a parameter to the function interface, pOverflow which is
+ a pointer to the overflow flag. This flag is required by the
+ L_add() function invoked by round().
+ Removed code that updates the MOPS counter.
+ Created a new return variable result.
+
+ Description: Removed embedded tabs. Included comment in the Pseudo code
+ Section about using pointer to overflow flag in the actual
+ implementation instead of using a global flag.
+
+ Description: Changed function name to pv_round to avoid conflict with
+ round function in C standard library.
+
+ Who: Date:
+ Description:
+
+------------------------------------------------------------------------------
+ MODULE DESCRIPTION
+
+ Rounding function with saturation.
+
+------------------------------------------------------------------------------
+*/
+
+/*----------------------------------------------------------------------------
+; INCLUDES
+----------------------------------------------------------------------------*/
+#include "basic_op.h"
+
+/*----------------------------------------------------------------------------
+; MACROS
+; [Define module specific macros here]
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; DEFINES
+; [Include all pre-processor statements here. Include conditional
+; compile variables also.]
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL FUNCTION DEFINITIONS
+; [List function prototypes here]
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL VARIABLE DEFINITIONS
+; [Variable declaration - defined here and used outside this module]
+----------------------------------------------------------------------------*/
+
+/*
+------------------------------------------------------------------------------
+ FUNCTION NAME: pv_round
+------------------------------------------------------------------------------
+ INPUT AND OUTPUT DEFINITIONS
+
+ Inputs:
+ L_var1 = 32 bit signed integer (Word32) whose value falls
+ in the range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.
+
+ pOverflow = pointer to overflow (Flag)
+
+ Outputs:
+ None
+
+ Returns:
+ result = MS 16 bits of rounded input L_var1.
+
+ Global Variables Used:
+ None
+
+ Local Variables Needed:
+ None
+
+------------------------------------------------------------------------------
+ FUNCTION DESCRIPTION
+
+ This function rounds the lower 16 bits of the 32 bit input number into the
+ MS 16 bits with saturation. Shift the resulting bits right by 16 and return
+ the 16 bit number:
+ pv_round(L_var1) = extract_h(L_add(L_var1,32768))
+
+------------------------------------------------------------------------------
+ REQUIREMENTS
+
+ None
+
+------------------------------------------------------------------------------
+ REFERENCES
+
+ [1] round() function in basic_op2.c, UMTS GSM AMR speech codec, R99 -
+ Version 3.2.0, March 2, 2001
+
+------------------------------------------------------------------------------
+ PSEUDO-CODE
+
+Word16 pv_round (Word32 L_var1)
+{
+ Word16 var_out;
+ Word32 L_rounded;
+
+* The reference ETSI code uses a global flag for Overflow in the L_add() function.
+* In the actual implementation a pointer to Overflow flag is passed in as a
+* parameter to the function.
+
+ L_rounded = L_add (L_var1, (Word32) 0x00008000L);
+#if (WMOPS)
+ multiCounter[currCounter].L_add--;
+#endif
+ var_out = extract_h (L_rounded);
+#if (WMOPS)
+ multiCounter[currCounter].extract_h--;
+ multiCounter[currCounter].round++;
+#endif
+ return (var_out);
+}
+
+------------------------------------------------------------------------------
+ RESOURCES USED [optional]
+
+ When the code is written for a specific target processor the
+ the resources used should be documented below.
+
+ HEAP MEMORY USED: x bytes
+
+ STACK MEMORY USED: x bytes
+
+ CLOCK CYCLES: (cycle count equation for this function) + (variable
+ used to represent cycle count for each subroutine
+ called)
+ where: (cycle count variable) = cycle count for [subroutine
+ name]
+
+------------------------------------------------------------------------------
+ CAUTION [optional]
+ [State any special notes, constraints or cautions for users of this function]
+
+------------------------------------------------------------------------------
+*/
+
+/*----------------------------------------------------------------------------
+; FUNCTION CODE
+----------------------------------------------------------------------------*/
+Word16 pv_round(register Word32 L_var1, Flag *pOverflow)
+{
+ Word16 result;
+
+ L_var1 = L_add(L_var1, (Word32) 0x00008000L, pOverflow);
+ result = (Word16)(L_var1 >> 16);
+
+ return (result);
+}