bits2prm.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

/*
********************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : bits2prm.c
*
********************************************************************************
*/
/*
********************************************************************************
*                         MODULE INCLUDE FILE AND VERSION ID
********************************************************************************
*/
#include "bits2prm.h"
const char bits2prm_id[] = "@(#)$Id $" bits2prm_h;
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "typedef.h"
#include "basic_op.h"
#include "count.h"
#include "mode.h"

#include <stdlib.h>
#include <stdio.h>

/*
********************************************************************************
*                         LOCAL VARIABLES AND TABLES
********************************************************************************
*/
#include "bitno.tab"

/*
********************************************************************************
*                         LOCAL PROGRAM CODE
********************************************************************************
*/

/*
**************************************************************************
*
*  Function    : Bin2int
*  Purpose     : Read "no_of_bits" bits from the array bitstream[] 
*                and convert to integer.
*
**************************************************************************
*/
static Word16 Bin2int ( /* Reconstructed parameter                      */
    Word16 no_of_bits,  /* input : number of bits associated with value */
    Word16 *bitstream   /* output: address where bits are written       */
)
{
    Word16 value, i, bit;

    value = 0;                                  move16 (); 
    for (i = 0; i < no_of_bits; i++)
    {
        value = shl (value, 1);
        bit = *bitstream++;                     move16 (); 
        test (); 
        if (sub (bit, BIT_1) == 0)
            value = add (value, 1);
    }
    return (value);
}

/*
********************************************************************************
*                         PUBLIC PROGRAM CODE
********************************************************************************
*/
/*
**************************************************************************
*
*  Function    : Bits2prm
*  Purpose     : Retrieves the vector of encoder parameters from 
*                the received serial bits in a frame.
*
**************************************************************************
*/
void Bits2prm (
    enum Mode mode,     /* i : AMR mode                                    */
    Word16 bits[],      /* i : serial bits       (size <= MAX_SERIAL_SIZE) */
    Word16 prm[]        /* o : analysis parameters  (size <= MAX_PRM_SIZE) */
)
{
    Word16 i;

    move16();           /* account for pointer init (bitno[mode])  */
    
    for (i = 0; i < prmno[mode]; i++)
    {
        prm[i] = Bin2int (bitno[mode][i], bits);      move16 (); 
        bits += bitno[mode][i];
        add(0,0);       /* account for above pointer update  */
    }
    
   return;
}