/************************************************************	Copyright (C) 2002	Sigma Designs, Inc. All Rights Reserved	Proprietary and Confidential    Author: David Weiguo Zheng			<david_zheng@sdesigns.com>    File Name: bitWrite.h	Purpose: All functions to handle bit writing**************************************************************/#ifndef _BITWRITE_H_#define _BITWRITE_H_typedef struct{	i32 pos;	u32 reg;	u32 * buf;	u32 * ptr;}BitWriter;static void bw_init(BitWriter * const bw, void * const pointer);static u32 bw_length(BitWriter * const bw);static void bw_put1(BitWriter * const bw, const u32 bit);static void bw_put(BitWriter * const bw, const u32 value, const i32 size);static void bw_pad(BitWriter * const bw);/* initialize bitstream structure */static void bw_init(BitWriter * const bw, void * const pointer){    bw->reg = bw->pos = 0;	bw->buf = (u32 *)pointer;	bw->ptr = bw->buf;}/* bitstream length (unit bits) */static u32 bw_length(BitWriter * const bw){	u32 len = (u32) bw->ptr - (u32) bw->buf;    if (bw->pos)    {		u32 ui32 = bw->reg;		ui32 = (ui32<<16) | (ui32>>16);		*bw->ptr = ((ui32<<8)&0xff00ff00) | ((ui32>>8)&0xff00ff);		len += ((bw->pos + 7) >> 3);    }	return len;}/* write single bit to bitstream */static void bw_put1(BitWriter * const bw, const u32 bit){    if (bit)		bw->reg |= (0x80000000 >> bw->pos);    bw->pos ++;    if (bw->pos > 31)    {		u32 ui32 = bw->reg;		ui32 = (ui32<<16) | (ui32>>16);		bw->reg = 0;		*bw->ptr++ = ((ui32<<8)&0xff00ff00) | ((ui32>>8)&0xff00ff);				bw->pos -= 32;    }}/* put n bits to bitwriter */static void bw_put(BitWriter * const bw, const u32 value, const i32 size){  if(size)  {	i32 shift = 32 - bw->pos - size;	if (shift>0) {		// there is more than enough bits available to insert the data		bw->reg |= (value << shift);		bw->pos += size;		return;	} 	else	{	   if(shift)    // no enough bits to insert data		   {		// 32bit cache buffer full, need to flush the cache and update again		i32 room = 32-bw->pos;		i32 first_shift = size-room;		u32 ui32 = bw->reg | (value >> first_shift);				ui32 = (ui32<<16) | (ui32>>16);		room = 32-first_shift;		*bw->ptr++ = ((ui32<<8)&0xff00ff00) | ((ui32>>8)&0xff00ff);		bw->reg = (value << room);				bw->pos = first_shift;		return;	   }	   else//	if(shift == 0)	   {		u32 ui32 = bw->reg | (value << shift);		ui32 = (ui32<<16) | (ui32>>16);				*bw->ptr++ = ((ui32<<8)&0xff00ff00) | ((ui32>>8)&0xff00ff);		bw->pos = 0;		bw->reg = 0;		return;	   }	}  }}/* pad bitwriter bitstream to align byte boundary */static void bw_pad(BitWriter * const bw){	i32 remainder = bw->pos & 7;    if (remainder)    {				if(remainder < 8)		{		bw_put1(bw, 0);		remainder ++;		}		// still needs padding		if(remainder < 8)		{		  u32 padding_bits = 0xff >> remainder;		  bw_put(bw, padding_bits, 8-remainder);		}    }}#endif /* _BITWRITE_H_ */