www.pudn.com > wavecode.rar > coder_bpbf.c

 
/***** 
 
BP Binary Fast 
 
*****/ 
 
#include  
#include  
#include  
#include  
#include "coder.h" 
 
extern int tune_param; 
 
#define	VAL_CONTEXTS		16 
#define	VAL_CONTEXT_MAX		(VAL_CONTEXTS -1) 
#define SHAPE_BASE			VAL_CONTEXTS 
#define SHAPE(x)			(SHAPE_BASE<<(x)) 
#define NUM_SHAPES			2 
#define NUM_CONTEXTS		(VAL_CONTEXTS< TOTMAX ) { PT >>= 1; P0 >>= 1; P0++; PT += 2; } } while(0) 
#define bitEnc(bit,ari,P0,PT)	do { arithEncBit(ari,P0,PT,bit);	bitModel(bit,P0,PT); } while(0) 
#define bitDec(bit,ari,P0,PT)	do { bit = arithDecBit(ari,P0,PT);	bitModel(bit,P0,PT); } while(0) 
 
void coderBPBF_encodeBandBP(coder *me,int *band,int w,int h,int fullw,int *parent,int); 
void coderBPBF_decodeBandBP(coder *me,int *band,int w,int h,int fullw,int *parent,int); 
 
typedef struct { 
	int signs_p0[SIGN_CONTEXTS]; 
	int signs_pt[SIGN_CONTEXTS]; 
	int stats_p0[NUM_CONTEXTS]; 
	int stats_pt[NUM_CONTEXTS]; 
} myInfo; 
 
void coderBPBF_init(coder *c) 
{ 
myInfo *d; 
int i; 
 
	if ( (d = new(myInfo)) == NULL ) 
		errexit("ozero init failed"); 
 
	c->data = d; 
 
	for(i=0;istats_p0[i] = P0_INIT+1; d->stats_pt[i] = 2+P0_INIT+P1_INIT; 
	} 
 
	for(i=0;isigns_p0[i] = 100; 
		d->signs_pt[i] = 200; 
	} 
 
} 
 
void coderBPBF_free(coder *c) 
{ 
	if ( c->data ) { 
		myInfo *d; 
		d = c->data; 
		free(d); 
		c->data = NULL; 
	} 
} 
 
coder coderBPBF = { 
		"BP Bin Fast", 
		coderBPBF_init, 
		coderBPBF_free, 
		NULL,NULL, 
		coderBPBF_encodeBandBP, 
		coderBPBF_decodeBandBP 
	}; 
 
/********** 
 
lazy way to pass the state from getStats to fixStats 
	and also interacts with the codeBand() 
 
these are re-initialized at each codeBand() call, so this is 
	quite re-entrant as long as we aren't multi-threaded 
	(that is, no more than one call to codeBand() at a time) 
 
*********/ 
 
static int VD,donemask,nextmask,sign_context; 
 
static int mcontext(int *dp,int pp,int x,int y,int fullw) 
{ 
int P,N,W; 
int context; 
 
	/** <> all these absolute values are painfully slow ***/ 
 
	VD	= abs(*dp)&donemask;	// current val already done 
	P	= abs(pp)&nextmask; 
 
	sign_context = 0; 
 
	if ( y == 0 ) { 
		N = VD; 
		if ( x == 0 ) W = VD; else W = abs(dp[-1]) & nextmask; 
		if ( W ) { 
			if ( isneg(dp[-1]) ) sign_context += 3; 
			else sign_context += 6; 
		} 
	} else if ( x == 0 ) { 
		W = VD; 
		N  = abs(dp[-fullw])	& nextmask; 
		if ( N ) { 
			if ( isneg(dp[-fullw]) ) sign_context += 1; 
			else sign_context += 2; 
		} 
	} else { 
		N = abs(dp[-fullw])		& nextmask; 
		W = abs(dp[-1])			& nextmask; 
		if ( N ) { 
			if ( isneg(dp[-fullw]) ) sign_context += 1; 
			else sign_context += 2; 
		} 
		if ( W ) { 
			if ( isneg(dp[-1]) ) sign_context += 3; 
			else sign_context += 6; 
		} 
	} 
 
	context = min(VAL_CONTEXT_MAX, ((VD + P + N + W)>>2)); 
 
	if ( N > VD ) context += VAL_CONTEXTS;  
	if ( W > VD ) context += VAL_CONTEXTS+VAL_CONTEXTS; 
 
return context; 
} 
 
void coderBPBF_encodeBandBP(coder *me,int *band,int width,int height,int fullw,int *parent,int bitmask) 
{ 
int x,y,bit,context; 
int *dp,*pp; 
arithInfo *ari = me->arith; 
int *signs_p0,*signs_pt; 
int *stats_p0,*stats_pt; 
 
	stats_p0 = ((myInfo *)me->data)->stats_p0; 
	stats_pt = ((myInfo *)me->data)->stats_pt; 
	signs_p0 = ((myInfo *)me->data)->signs_p0; 
	signs_pt = ((myInfo *)me->data)->signs_pt; 
 
	for(x=bitmask,nextmask=0; x<(1<<29) ;x<<=1) nextmask += x; 
	donemask = nextmask - bitmask; 
 
	dp = band;	pp = parent; 
	for(y=0;y>1],x,y,fullw); 
 
			bit = (abs(dp[x])&bitmask)?1:0; 
			bitEnc(bit,ari,stats_p0[context],stats_pt[context]); 
 
			if ( bit && !VD ) { 
				bitEnc( signbit(dp[x]) ,ari,signs_p0[sign_context],signs_pt[sign_context]); 
			} 
		} 
		if ( y&1 ) pp += fullw; 
		dp += fullw; 
	} 
} 
 
void coderBPBF_decodeBandBP(coder *me,int *band,int width,int height,int fullw,int *parent,int bitmask) 
{ 
int x,y,bit,context; 
int *dp,*pp; 
arithInfo *ari = me->arith; 
int *signs_p0,*signs_pt; 
int *stats_p0,*stats_pt; 
 
	stats_p0 = ((myInfo *)me->data)->stats_p0; 
	stats_pt = ((myInfo *)me->data)->stats_pt; 
	signs_p0 = ((myInfo *)me->data)->signs_p0; 
	signs_pt = ((myInfo *)me->data)->signs_pt; 
 
	for(x=bitmask,nextmask=0; x<(1<<29) ;x<<=1) nextmask += x; 
	donemask = nextmask - bitmask; 
 
	dp = band;	pp = parent; 
	for(y=0;y>1],x,y,fullw); 
 
			bitDec(bit,ari,stats_p0[context],stats_pt[context]); 
 
			if ( bit ) { 
				if ( ! VD ) { 
					bitDec(bit,ari,signs_p0[sign_context],signs_pt[sign_context]); 
					if ( bit ) dp[x] = - bitmask; 
					else dp[x] = bitmask; 
				} else { 
					if ( isneg(dp[x]) ) dp[x] -= bitmask; 
					else dp[x] += bitmask;  
				} 
			} 
		} 
		if ( y&1 ) pp += fullw; 
		dp += fullw; 
	} 
}