www.pudn.com > speakFreely-code.zip > acb_ex.c

/*======================================================================*/ 
/*     Enhanced Variable Rate Codec - Bit-Exact C Specification         */ 
/*     Copyright (C) 1997-1998 Telecommunications Industry Association. */ 
/*     All rights reserved.                                             */ 
/*----------------------------------------------------------------------*/ 
/* Note:  Reproduction and use of this software for the design and      */ 
/*     development of North American Wideband CDMA Digital              */ 
/*     Cellular Telephony Standards is authorized by the TIA.           */ 
/*     The TIA does not authorize the use of this software for any      */ 
/*     other purpose.                                                   */ 
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/*     The availability of this software does not provide any license   */ 
/*     by implication, estoppel, or otherwise under any patent rights   */ 
/*     of TIA member companies or others covering any use of the        */ 
/*     contents herein.                                                 */ 
/*                                                                      */ 
/*     Any copies of this software or derivative works must include     */ 
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/*======================================================================*/ 
/*  Module:     acb_ex.c                                                */ 
/*  Memory Usage:                                                       */ 
/*      ROM:                0                                           */ 
/*      Static/Global RAM:  0                                           */ 
/*      Stack/Local RAM:    0                                           */ 
/*----------------------------------------------------------------------*/ 
/************************************************************************ 
* Routine name: acb_excitation                                          * 
* Function: Adaptive codebook excitation.                               * 
************************************************************************/ 
 
#include "mathevrc.h" 
#include "mathdp31.h" 
#include "mathadv.h" 
#include "macro.h" 
 
void acb_excitation(short *Ex1, short gain, long *delay3, short *PitchMemory, short length) 
{ 
	register short i; 
	long Ltemp; 
 
	putacbc(Ex1, PitchMemory + ACBMemSize, 0, length, 10, delay3, BLFREQ, BLPRECISION); 
 
	/* Scale excitation */ 
	for (i = 0; i < length; i++) 
	{ 
		Ltemp = L_mult(Ex1[i], gain); 
		Ex1[i] = round(L_shl(Ltemp, 1));	/*To account for 1/2 scale in gain */ 
	} 
}