packing.c File Reference

#include <math.h>
#include <stdlib.h>
#include "iLBC_define.h"
#include "constants.h"
#include "helpfun.h"
#include "string.h"

Include dependency graph for packing.c:

Go to the source code of this file.

Functions
void	dopack (unsigned char **bitstream, int index, int bitno, int *pos)
void	packcombine (int *index, int rest, int bitno_rest)
void	packsplit (int *index, int *firstpart, int *rest, int bitno_firstpart, int bitno_total)
void	unpack (unsigned char **bitstream, int *index, int bitno, int *pos)

Function Documentation

dopack()

void dopack	(	unsigned char **	bitstream,
		int	index,
		int	bitno,
		int *	pos
	)

Definition at line 68 of file packing.c.

    {
       int posLeft;
 
       /* Clear the bits before starting in a new byte */
 
       if ((*pos)==0) {
 
 
 
 
 
           **bitstream=0;
       }
 
       while (bitno>0) {
 
           /* Jump to the next byte if end of this byte is reached*/
 
           if (*pos==8) {
               *pos=0;
               (*bitstream)++;
               **bitstream=0;
           }
 
           posLeft=8-(*pos);
 
           /* Insert index into the bitstream */
 
           if (bitno <= posLeft) {
               **bitstream |= (unsigned char)(index<<(posLeft-bitno));
               *pos+=bitno;
               bitno=0;
           } else {
               **bitstream |= (unsigned char)(index>>(bitno-posLeft));
 
               *pos=8;
               index-=((index>>(bitno-posLeft))<<(bitno-posLeft));
 
               bitno-=posLeft;
           }
       }
   }

Referenced by iLBC_encode().

packcombine()

void packcombine	(	int *	index,
		int	rest,
		int	bitno_rest
	)

Definition at line 53 of file packing.c.

    {
       *index = *index<<bitno_rest;
       *index += rest;
   }

Referenced by iLBC_decode().

packsplit()

void packsplit	(	int *	index,
		int *	firstpart,
		int *	rest,
		int	bitno_firstpart,
		int	bitno_total
	)

Definition at line 26 of file packing.c.

    {
       int bitno_rest = bitno_total-bitno_firstpart;
 
       *firstpart = *index>>(bitno_rest);
       *rest = *index-(*firstpart<<(bitno_rest));
   }

Referenced by iLBC_encode().

unpack()

void unpack	(	unsigned char **	bitstream,
		int *	index,
		int	bitno,
		int *	pos
	)

Definition at line 126 of file packing.c.

    {
       int BitsLeft;
 
       *index=0;
 
       while (bitno>0) {
 
           /* move forward in bitstream when the end of the
              byte is reached */
 
           if (*pos==8) {
               *pos=0;
               (*bitstream)++;
           }
 
           BitsLeft=8-(*pos);
 
           /* Extract bits to index */
 
           if (BitsLeft>=bitno) {
               *index+=((((**bitstream)<<(*pos)) & 0xFF)>>(8-bitno));
 
               *pos+=bitno;
               bitno=0;
           } else {
 
               if ((8-bitno)>0) {
                   *index+=((((**bitstream)<<(*pos)) & 0xFF)>>
                       (8-bitno));
                   *pos=8;
               } else {
                   *index+=(((int)(((**bitstream)<<(*pos)) & 0xFF))<<
                       (bitno-8));
                   *pos=8;
               }
               bitno-=BitsLeft;
           }
       }
   }

Referenced by iLBC_decode().