/* ------------------------------------------------------------------ * 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/l_extract.c Date: 09/07/2000 ------------------------------------------------------------------------------ REVISION HISTORY Description: Updated template. Changed function interface to pass in a pointer to overflow flag into the function instead of using a global flag. Changed names of function parameters for clarity. Removed inclusion of unwanted header files. Description: ------------------------------------------------------------------------------ */ /*---------------------------------------------------------------------------- ; 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: L_extract ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Inputs: L_var = 32 bit signed integer (Word32) whose value falls in the range : 0x8000 0000 <= L_32 <= 0x7fff ffff. pL_var_hi = pointer to the most significant word of L_var (Word16). pL_var_lo = pointer to the least significant word of L_var shifted to the left by 1 (Word16). pOverflow = pointer to overflow (Flag) Outputs: pOverflow -> 1 if the 32 bit add operation resulted in overflow pL_var_hi -> MS word of L_32. pL_var_lo -> LS word of L_32 shifted left by 1. Returns: None Global Variables Used: None Local Variables Needed: None ------------------------------------------------------------------------------ FUNCTION DESCRIPTION This function extracts two 16-bit double precision format (DPF) numbers from a 32-bit integer. The MS word of L_var will be stored in the location pointed to by pL_var_hi and the shifted LS word of L_var will be stored in the location pointed to by pL_var_lo. ------------------------------------------------------------------------------ REQUIREMENTS None ------------------------------------------------------------------------------ REFERENCES [1] L_extract() function in oper_32b.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 ------------------------------------------------------------------------------ PSEUDO-CODE ------------------------------------------------------------------------------ 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 ----------------------------------------------------------------------------*/ void L_Extract(Word32 L_var, Word16 *pL_var_hi, Word16 *pL_var_lo, Flag *pOverflow) { Word32 temp; OSCL_UNUSED_ARG(pOverflow); temp = (L_var >> 16); *(pL_var_hi) = (Word16) temp; *(pL_var_lo) = (Word16)((L_var >> 1) - (temp << 15)); return; }