faxexpand.c

来自「涉及Fax/Mail/Voice通讯编程的一个程序」· C语言 代码 · 共 730 行 · 第 1/2 页

	expand1d();
	if (RunLength)
	    SETVAL(0);
	if (a0 != lastx) {
	    if (verbose)
		fprintf(stderr, "Line %d: length is %d (expected %d)\n", LineNum, a0, lastx);
	    while (a0 > lastx)
		a0 -= *--pa;
	    if (a0 < lastx) {
		if ((pa - runs) & 1)
		    SETVAL(0);
		SETVAL(lastx - a0);
	    }
	}
	(*df)(runs, LineNum++, pn);
    }
    free(runs);
}

/* Expand group-3 1-dimensional data */
void
g31expand(struct pagenode *pn, drawfunc df)
{
    int a0;			/* reference element */
    int lastx = pn->width;	/* copy line width to register */
    t32bits BitAcc;		/* bit accumulator */
    int BitsAvail;		/* # valid bits in BitAcc */
    int RunLength;		/* Length of current run */
    t16bits *sp;		/* pointer into compressed data */
    pixnum *pa;			/* pointer into new line */
    int EOLcnt;			/* number of consecutive EOLs */
    int	LineNum;		/* line number */
    pixnum *runs;		/* list of run lengths */
    struct tabent *TabEnt;

    sp = pn->data;
    BitAcc = 0;
    BitsAvail = 0;
    lastx = pn->width;
    runs = (pixnum *) xmalloc(lastx * sizeof(pixnum));
    EOLcnt = 0;
    for (LineNum = 0; LineNum < pn->rowsperstrip; ) {
#ifdef DEBUG
	printf("\nBitAcc=%08lX, BitsAvail = %d\n", BitAcc, BitsAvail);
	printf("-------------------- %d\n", LineNum);
	fflush(stdout);
#endif
	if (EOLcnt == 0)
	    while (!EndOfData(pn)) {
		/* skip over garbage after a coding error */
		NeedBits(11);
		if (GetBits(11) == 0)
		    break;
		ClrBits(1);
	    }
	for (EOLcnt = 1; !EndOfData(pn); EOLcnt++) {
	    /* we have seen 11 zeros, which implies EOL,
	       skip possible fill bits too */
	    while (1) {
		NeedBits(8);
		if (GetBits(8))
		    break;
		ClrBits(8);
	    }
	    while (GetBits(1) == 0)
		ClrBits(1);
	    ClrBits(1);		/* the eol flag */
	    NeedBits(11);
	    if (GetBits(11))
		break;
	    ClrBits(11);
	}
	if (EOLcnt > 1 && EOLcnt != 6 && verbose)
	    fprintf(stderr, "Line %d: bad RTC (%d EOLs)\n", LineNum, EOLcnt);
	if (EOLcnt >= 6 || EndOfData(pn)) {
	    free(runs);
	    return;
	}
	RunLength = 0;
	pa = runs;
	a0 = 0;
	EOLcnt = 0;
	expand1d();
	if (RunLength)
	    SETVAL(0);
	if (a0 != lastx) {
	    if (verbose)
		fprintf(stderr, "Line %d: length is %d (expected %d)\n", LineNum, a0, lastx);
	    while (a0 > lastx)
		a0 -= *--pa;
	    if (a0 < lastx) {
		if ((pa - runs) & 1)
		    SETVAL(0);
		SETVAL(lastx - a0);
	    }
	}
	(*df)(runs, LineNum++, pn);
    }
    free(runs);
}

/* Expand group-3 2-dimensional data */
void
g32expand(struct pagenode *pn, drawfunc df)
{
    int RunLength;		/* Length of current run */
    int a0;			/* reference element */
    int b1;			/* next change on previous line */
    int lastx = pn->width;	/* copy line width to register */
    pixnum *run0, *run1;	/* run length arrays */
    pixnum *thisrun, *pa, *pb;	/* pointers into runs */
    t16bits *sp;		/* pointer into compressed data */
    t32bits BitAcc;		/* bit accumulator */
    int BitsAvail;		/* # valid bits in BitAcc */
    int EOLcnt;			/* number of consecutive EOLs */
    int	refline = 0;		/* 1D encoded reference line */
    int	LineNum;		/* line number */
    struct tabent *TabEnt;

    sp = pn->data;
    BitAcc = 0;
    BitsAvail = 0;
    /* allocate space for 2 runlength arrays */
    run0 = (pixnum *) xmalloc(2 * ((lastx+5)&~1) * sizeof(pixnum));
    run1 = run0 + ((lastx+5)&~1);
    run1[0] = lastx;
    run1[1] = 0;
    EOLcnt = 0;
    for (LineNum = 0; LineNum < pn->rowsperstrip; ) {
#ifdef DEBUG
	printf("\nBitAcc=%08lX, BitsAvail = %d\n", BitAcc, BitsAvail);
	printf("-------------------- %d\n", LineNum);
	fflush(stdout);
#endif
	if (EOLcnt == 0)
	    while (!EndOfData(pn)) {
		/* skip over garbage after a coding error */
		NeedBits(11);
		if (GetBits(11) == 0)
		    break;
		ClrBits(1);
	    }
	for (EOLcnt = 1; !EndOfData(pn); EOLcnt++) {
	    /* we have seen 11 zeros, which implies EOL,
	       skip possible fill bits too */
	    while (1) {
		NeedBits(8);
		if (GetBits(8))
		    break;
		ClrBits(8);
	    }
	    while (GetBits(1) == 0)
		ClrBits(1);
	    ClrBits(1);		/* the eol flag */
	    NeedBits(12);
	    refline = GetBits(1); /* 1D / 2D flag */
	    ClrBits(1);
	    if (GetBits(11))
		break;
	    ClrBits(11);
	}
	if (EOLcnt > 1 && EOLcnt != 6 && verbose)
	    fprintf(stderr, "Line %d: bad RTC (%d EOLs)\n", LineNum, EOLcnt);
	if (EOLcnt >= 6 || EndOfData(pn)) {
	    free(run0);
	    return;
	}
	if (LineNum == 0 && refline == 0 && verbose)
	    fprintf(stderr, "First line is 2-D encoded\n");
	RunLength = 0;
	if (LineNum & 1) {
	    pa = run1;
	    pb = run0;
	}
	else {
	    pa = run0;
	    pb = run1;
	}
	thisrun = pa;
	EOLcnt = 0;
	a0 = 0;
	b1 = *pb++;

	if (refline) {
	    expand1d();
	}
	else {
	    expand2d(EOL2);
	}
	if (RunLength)
	    SETVAL(0);
	if (a0 != lastx) {
	    if (verbose)
		fprintf(stderr, "Line %d: length is %d (expected %d)\n", LineNum, a0, lastx);
	    while (a0 > lastx)
		a0 -= *--pa;
	    if (a0 < lastx) {
		if ((pa - run0) & 1)
		    SETVAL(0);
		SETVAL(lastx - a0);
	    }
	}
	SETVAL(0);	/* imaginary change at end of line for reference */
	(*df)(thisrun, LineNum++, pn);
    }
    free(run0);
}

/* Redefine the "skip to eol" macro.  We cannot recover from coding
   errors in G4 data */
#undef SKIP_EOL
#undef eol2lab
#define SKIP_EOL do {							\
    if (verbose)							\
	fprintf(stderr, "Line %d: G4 coding error\n", LineNum);		\
    free(run0);								\
    return;								\
} while (0)
#define eol2lab

/* Expand group-4 data */
void
g4expand(struct pagenode *pn, drawfunc df)
{
    int RunLength;		/* Length of current run */
    int a0;			/* reference element */
    int b1;			/* next change on previous line */
    int lastx = pn->width;	/* copy line width to register */
    pixnum *run0, *run1;	/* run length arrays */
    pixnum *thisrun, *pa, *pb;	/* pointers into runs */
    t16bits *sp;		/* pointer into compressed data */
    t32bits BitAcc;		/* bit accumulator */
    int BitsAvail;		/* # valid bits in BitAcc */
    int	LineNum;		/* line number */
    int EOLcnt;
    struct tabent *TabEnt;

    sp = pn->data;
    BitAcc = 0;
    BitsAvail = 0;
    /* allocate space for 2 runlength arrays */
    run0 = (pixnum *) xmalloc(2 * ((lastx+5)&~1) * sizeof(pixnum));
    run1 = run0 + ((lastx+5)&~1);
    run1[0] = lastx;		/* initial reference line */
    run1[1] = 0;

    for (LineNum = 0; LineNum < pn->rowsperstrip; ) {
#ifdef DEBUG
	printf("\nBitAcc=%08lX, BitsAvail = %d\n", BitAcc, BitsAvail);
	printf("-------------------- %d\n", LineNum);
	fflush(stdout);
#endif
	RunLength = 0;
	if (LineNum & 1) {
	    pa = run1;
	    pb = run0;
	}
	else {
	    pa = run0;
	    pb = run1;
	}
	thisrun = pa;
	a0 = 0;
	b1 = *pb++;
	expand2d(EOFB);
	if (a0 < lastx) {
	    if ((pa - run0) & 1)
		SETVAL(0);
	    SETVAL(lastx - a0);
	}
	SETVAL(0);	/* imaginary change at end of line for reference */
	(*df)(thisrun, LineNum++, pn);
	continue;
    EOFB:
	NeedBits(13);
	if (GetBits(13) != 0x1001 && verbose)
	    fputs("Bad RTC\n", stderr);
	break;
    }
    free(run0);
}

static unsigned char zerotab[256] = {
	0x88, 0x07, 0x16, 0x06, 0x25, 0x05, 0x15, 0x05,
	0x34, 0x04, 0x14, 0x04, 0x24, 0x04, 0x14, 0x04,
	0x43, 0x03, 0x13, 0x03, 0x23, 0x03, 0x13, 0x03,
	0x33, 0x03, 0x13, 0x03, 0x23, 0x03, 0x13, 0x03,
	0x52, 0x02, 0x12, 0x02, 0x22, 0x02, 0x12, 0x02,
	0x32, 0x02, 0x12, 0x02, 0x22, 0x02, 0x12, 0x02,
	0x42, 0x02, 0x12, 0x02, 0x22, 0x02, 0x12, 0x02,
	0x32, 0x02, 0x12, 0x02, 0x22, 0x02, 0x12, 0x02,
	0x61, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x31, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x41, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x31, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x51, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x31, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x41, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x31, 0x01, 0x11, 0x01, 0x21, 0x01, 0x11, 0x01,
	0x70, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x40, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x50, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x40, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x60, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x40, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x50, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x40, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00,
	0x30, 0x00, 0x10, 0x00, 0x20, 0x00, 0x10, 0x00
};

#define check(v) do {							\
    prezeros = zerotab[v];						\
    postzeros = prezeros & 15;						\
    prezeros >>= 4;							\
    if (prezeros == 8) {						\
	zeros += 8;							\
	continue;							\
    }									\
    if (zeros + prezeros < 11) {					\
	empty = 0;							\
	zeros = postzeros;						\
	continue;							\
    }									\
    zeros = postzeros;							\
    if (empty)								\
	EOLcnt++;							\
    lines++;								\
    empty = 1;								\
} while (0)

/* count fax lines */
int
G3count(struct pagenode *pn, int twoD)
{
    t16bits *p = pn->data;
    t16bits *end = p + pn->length/sizeof(*p);
    int lines = 0;		/* lines seen so far */
    int zeros = 0;		/* number of consecutive zero bits seen */
    int EOLcnt = 0;		/* number of consecutive EOLs seen */
    int empty = 1;		/* empty line */
    int prezeros, postzeros;

    while (p < end && EOLcnt < 6) {
	t16bits bits = *p++;
	check(bits&255);
	if (twoD && (prezeros + postzeros == 7)) {
	    if (postzeros || ((bits & 0x100) == 0))
		zeros--;
	}
	check(bits>>8);
	if (twoD && (prezeros + postzeros == 7)) {
	    if (postzeros || ((p < end) && ((*p & 1) == 0)))
		zeros--;
	}
    }
    return lines - EOLcnt;	/* don't count trailing EOLs */
}