utils.c

linux下摄像头采集的图像格式转换工具

	    if (m == M_EOF) {
		if (in->func && (m = in->func(in->data)) == 0)
		    continue;
	    }
	    in->marker = m;
	    if (le <= 16)
		bi = bi << 16, le += 16;
	    break;
	}
	bi = bi << 8 | b;
	le += 8;
    }
    in->bits = bi;		/* tmp... 2 return values needed */
    return le;
}

static int dec_readmarker(in)
struct in *in;
{
    int m;

    in->left = fillbits(in, in->left, in->bits);
    if ((m = in->marker) == 0)
	return 0;
    in->left = 0;
    in->marker = 0;
    return m;
}

#define LEBI_DCL	int le, bi
#define LEBI_GET(in)	(le = in->left, bi = in->bits)
#define LEBI_PUT(in)	(in->left = le, in->bits = bi)

#define GETBITS(in, n) (					\
  (le < (n) ? le = fillbits(in, le, bi), bi = in->bits : 0),	\
  (le -= (n)),							\
  bi >> le & ((1 << (n)) - 1)					\
)

#define UNGETBITS(in, n) (	\
  le += (n)			\
)


static int dec_rec2(in, hu, runp, c, i)
struct in *in;
struct dec_hufftbl *hu;
int *runp;
int c, i;
{
    LEBI_DCL;

    LEBI_GET(in);
    if (i) {
	UNGETBITS(in, i & 127);
	*runp = i >> 8 & 15;
	i >>= 16;
    } else {
	for (i = DECBITS;
	     (c = ((c << 1) | GETBITS(in, 1))) >= (hu->maxcode[i]); i++);
	if (i >= 16) {
	    in->marker = M_BADHUFF;
	    return 0;
	}
	i = hu->vals[hu->valptr[i] + c - hu->maxcode[i - 1] * 2];
	*runp = i >> 4;
	i &= 15;
    }
    if (i == 0) {		/* sigh, 0xf0 is 11 bit */
	LEBI_PUT(in);
	return 0;
    }
    /* receive part */
    c = GETBITS(in, i);
    if (c < (1 << (i - 1)))
	c += (-1 << i) + 1;
    LEBI_PUT(in);
    return c;
}

#define DEC_REC(in, hu, r, i)	 (	\
  r = GETBITS(in, DECBITS),		\
  i = hu->llvals[r],			\
  i & 128 ?				\
    (					\
      UNGETBITS(in, i & 127),		\
      r = i >> 8 & 15,			\
      i >> 16				\
    )					\
  :					\
    (					\
      LEBI_PUT(in),			\
      i = dec_rec2(in, hu, &r, r, i),	\
      LEBI_GET(in),			\
      i					\
    )					\
)

static void decode_mcus(in, dct, n, sc, maxp)
struct in *in;
int *dct;
int n;
struct scan *sc;
int *maxp;
{
    struct dec_hufftbl *hu;
    int i, r, t;
    LEBI_DCL;

    memset(dct, 0, n * 64 * sizeof(*dct));
    LEBI_GET(in);
    while (n-- > 0) {
	hu = sc->hudc.dhuff;
	*dct++ = (sc->dc += DEC_REC(in, hu, r, t));

	hu = sc->huac.dhuff;
	i = 63;
	while (i > 0) {
	    t = DEC_REC(in, hu, r, t);
	    if (t == 0 && r == 0) {
		dct += i;
		break;
	    }
	    dct += r;
	    *dct++ = t;
	    i -= r + 1;
	}
	*maxp++ = 64 - i;
	if (n == sc->next)
	    sc++;
    }
    LEBI_PUT(in);
}

static void dec_makehuff(hu, hufflen, huffvals)
struct dec_hufftbl *hu;
int *hufflen;
unsigned char *huffvals;
{
    int code, k, i, j, d, x, c, v;
    for (i = 0; i < (1 << DECBITS); i++)
	hu->llvals[i] = 0;

/*
 * llvals layout:
 *
 * value v already known, run r, backup u bits:
 *  vvvvvvvvvvvvvvvv 0000 rrrr 1 uuuuuuu
 * value unknown, size b bits, run r, backup u bits:
 *  000000000000bbbb 0000 rrrr 0 uuuuuuu
 * value and size unknown:
 *  0000000000000000 0000 0000 0 0000000
 */
    code = 0;
    k = 0;
    for (i = 0; i < 16; i++, code <<= 1) {	/* sizes */
	hu->valptr[i] = k;
	for (j = 0; j < hufflen[i]; j++) {
	    hu->vals[k] = *huffvals++;
	    if (i < DECBITS) {
		c = code << (DECBITS - 1 - i);
		v = hu->vals[k] & 0x0f;	/* size */
		for (d = 1 << (DECBITS - 1 - i); --d >= 0;) {
		    if (v + i < DECBITS) {	/* both fit in table */
			x = d >> (DECBITS - 1 - v - i);
			if (v && x < (1 << (v - 1)))
			    x += (-1 << v) + 1;
			x = x << 16 | (hu->vals[k] & 0xf0) << 4 |
			    (DECBITS - (i + 1 + v)) | 128;
		    } else
			x = v << 16 | (hu->vals[k] & 0xf0) << 4 |
			    (DECBITS - (i + 1));
		    hu->llvals[c | d] = x;
		}
	    }
	    code++;
	    k++;
	}
	hu->maxcode[i] = code;
    }
    hu->maxcode[16] = 0x20000;	/* always terminate decode */
}

/****************************************************************/
/**************             idct                  ***************/
/****************************************************************/

#define ONE ((PREC)IFIX(1.))
#define S2  ((PREC)IFIX(0.382683432))
#define C2  ((PREC)IFIX(0.923879532))
#define C4  ((PREC)IFIX(0.707106781))

#define S22 ((PREC)IFIX(2 * 0.382683432))
#define C22 ((PREC)IFIX(2 * 0.923879532))
#define IC4 ((PREC)IFIX(1 / 0.707106781))

#define C3IC1 ((PREC)IFIX(0.847759065))	/* c3/c1 */
#define C5IC1 ((PREC)IFIX(0.566454497))	/* c5/c1 */
#define C7IC1 ((PREC)IFIX(0.198912367))	/* c7/c1 */

#define XPP(a,b) (t = a + b, b = a - b, a = t)
#define XMP(a,b) (t = a - b, b = a + b, a = t)
#define XPM(a,b) (t = a + b, b = b - a, a = t)

#define ROT(a,b,s,c) (	t = IMULT(a + b, s),	\
			a = IMULT(a, c - s) + t,	\
			b = IMULT(b, c + s) - t)

#define IDCT		\
(			\
  XPP(t0, t1),		\
  XMP(t2, t3),		\
  t2 = IMULT(t2, IC4) - t3,	\
  XPP(t0, t3),		\
  XPP(t1, t2),		\
  XMP(t4, t7),		\
  XPP(t5, t6),		\
  XMP(t5, t7),		\
  t5 = IMULT(t5, IC4),	\
  ROT(t4, t6, S22, C22),\
  t6 -= t7,		\
  t5 -= t6,		\
  t4 -= t5,		\
  XPP(t0, t7),		\
  XPP(t1, t6),		\
  XPP(t2, t5),		\
  XPP(t3, t4)		\
)

static unsigned char zig2[64] = {
    0, 2, 3, 9, 10, 20, 21, 35,
    14, 16, 25, 31, 39, 46, 50, 57,
    5, 7, 12, 18, 23, 33, 37, 48,
    27, 29, 41, 44, 52, 55, 59, 62,
    15, 26, 30, 40, 45, 51, 56, 58,
    1, 4, 8, 11, 19, 22, 34, 36,
    28, 42, 43, 53, 54, 60, 61, 63,
    6, 13, 17, 24, 32, 38, 47, 49
};

void idct(in, out, quant, off, max)
int *in;
int *out;
PREC *quant;
PREC off;
int max;
{
    PREC t0, t1, t2, t3, t4, t5, t6, t7, t;
    PREC tmp[64], *tmpp;
    int i, j;
    unsigned char *zig2p;

    t0 = off;
    if (max == 1) {
	t0 += in[0] * quant[0];
	for (i = 0; i < 64; i++)
	    out[i] = ITOINT(t0);
	return;
    }
    zig2p = zig2;
    tmpp = tmp;
    for (i = 0; i < 8; i++) {
	j = *zig2p++;
	t0 += in[j] * quant[j];
	j = *zig2p++;
	t5 = in[j] * quant[j];
	j = *zig2p++;
	t2 = in[j] * quant[j];
	j = *zig2p++;
	t7 = in[j] * quant[j];
	j = *zig2p++;
	t1 = in[j] * quant[j];
	j = *zig2p++;
	t4 = in[j] * quant[j];
	j = *zig2p++;
	t3 = in[j] * quant[j];
	j = *zig2p++;
	t6 = in[j] * quant[j];
	IDCT;
	tmpp[0 * 8] = t0;
	tmpp[1 * 8] = t1;
	tmpp[2 * 8] = t2;
	tmpp[3 * 8] = t3;
	tmpp[4 * 8] = t4;
	tmpp[5 * 8] = t5;
	tmpp[6 * 8] = t6;
	tmpp[7 * 8] = t7;
	tmpp++;
	t0 = 0;
    }
    for (i = 0; i < 8; i++) {
	t0 = tmp[8 * i + 0];
	t1 = tmp[8 * i + 1];
	t2 = tmp[8 * i + 2];
	t3 = tmp[8 * i + 3];
	t4 = tmp[8 * i + 4];
	t5 = tmp[8 * i + 5];
	t6 = tmp[8 * i + 6];
	t7 = tmp[8 * i + 7];
	IDCT;
	out[8 * i + 0] = ITOINT(t0);
	out[8 * i + 1] = ITOINT(t1);
	out[8 * i + 2] = ITOINT(t2);
	out[8 * i + 3] = ITOINT(t3);
	out[8 * i + 4] = ITOINT(t4);
	out[8 * i + 5] = ITOINT(t5);
	out[8 * i + 6] = ITOINT(t6);
	out[8 * i + 7] = ITOINT(t7);
    }
}

static unsigned char zig[64] = {
    0, 1, 5, 6, 14, 15, 27, 28,
    2, 4, 7, 13, 16, 26, 29, 42,
    3, 8, 12, 17, 25, 30, 41, 43,
    9, 11, 18, 24, 31, 40, 44, 53,
    10, 19, 23, 32, 39, 45, 52, 54,
    20, 22, 33, 38, 46, 51, 55, 60,
    21, 34, 37, 47, 50, 56, 59, 61,
    35, 36, 48, 49, 57, 58, 62, 63
};

static PREC aaidct[8] = {
    IFIX(0.3535533906), IFIX(0.4903926402),
    IFIX(0.4619397663), IFIX(0.4157348062),
    IFIX(0.3535533906), IFIX(0.2777851165),
    IFIX(0.1913417162), IFIX(0.0975451610)
};


static void idctqtab(qin, qout)
unsigned char *qin;
PREC *qout;
{
    int i, j;

    for (i = 0; i < 8; i++)
	for (j = 0; j < 8; j++)
	    qout[zig[i * 8 + j]] = qin[zig[i * 8 + j]] *
		IMULT(aaidct[i], aaidct[j]);
}

static void scaleidctqtab(q, sc)
PREC *q;
PREC sc;
{
    int i;

    for (i = 0; i < 64; i++)
	q[i] = IMULT(q[i], sc);
}

/****************************************************************/
/**************          color decoder            ***************/
/****************************************************************/

#define ROUND

/*
 * YCbCr Color transformation:
 *
 * y:0..255   Cb:-128..127   Cr:-128..127
 *
 *      R = Y                + 1.40200 * Cr
 *      G = Y - 0.34414 * Cb - 0.71414 * Cr
 *      B = Y + 1.77200 * Cb
 *
 * =>
 *      Cr *= 1.40200;
 *      Cb *= 1.77200;
 *      Cg = 0.19421 * Cb + .50937 * Cr;
 *      R = Y + Cr;
 *      G = Y - Cg;
 *      B = Y + Cb;
 *
 * =>
 *      Cg = (50 * Cb + 130 * Cr + 128) >> 8;
 */

static void initcol(q)
PREC q[][64];
{
    scaleidctqtab(q[1], IFIX(1.77200));
    scaleidctqtab(q[2], IFIX(1.40200));
}

/* This is optimized for the stupid sun SUNWspro compiler. */
#define STORECLAMP(a,x)				\
(						\
  (a) = (x),					\
  (unsigned int)(x) >= 256 ? 			\
    ((a) = (x) < 0 ? 0 : 255)			\
  :						\
    0						\
)

#define CLAMP(x) ((unsigned int)(x) >= 256 ? ((x) < 0 ? 0 : 255) : (x))

#ifdef ROUND

#define CBCRCG(yin, xin)			\
(						\
  cb = outc[0 +yin*8+xin],			\
  cr = outc[64+yin*8+xin],			\
  cg = (50 * cb + 130 * cr + 128) >> 8		\
)

#else

#define CBCRCG(yin, xin)			\
(						\
  cb = outc[0 +yin*8+xin],			\
  cr = outc[64+yin*8+xin],			\
  cg = (3 * cb + 8 * cr) >> 4			\
)

#endif
// BGR instead RGB 
#define PIC(yin, xin, p, xout)			\
(						\
  y = outy[(yin) * 8 + xin],			\
  STORECLAMP(p[(xout) * 3 + 2], y + cr),	\
  STORECLAMP(p[(xout) * 3 + 1], y - cg),	\
  STORECLAMP(p[(xout) * 3 + 0], y + cb)		\
)



#define PIC221111(xin)						\
(								\
  CBCRCG(0, xin),						\
  PIC(xin / 4 * 8 + 0, (xin & 3) * 2 + 0, pic0, xin * 2 + 0),	\
  PIC(xin / 4 * 8 + 0, (xin & 3) * 2 + 1, pic0, xin * 2 + 1),	\
  PIC(xin / 4 * 8 + 1, (xin & 3) * 2 + 0, pic1, xin * 2 + 0),	\
  PIC(xin / 4 * 8 + 1, (xin & 3) * 2 + 1, pic1, xin * 2 + 1)	\
)

#define UV(yin, xin)			\
(						\
  u = outc[0 +yin*8+xin],			\
  v = outc[64+yin*8+xin]			\
)

#define PIC1(yin, xin, p, xout)			\
(						\
  y = outy[(yin) * 8 + xin],			\
  STORECLAMP(p[(xout) * 2 + 0], y),	\
  STORECLAMP(p[(xout) * 2 + 1], u + 128)	\
)

#define PIC2(yin, xin, p, xout)			\
(						\
  y = outy[(yin) * 8 + xin],			\
  STORECLAMP(p[(xout) * 2 + 0], y),	\
  STORECLAMP(p[(xout) * 2 + 1], v + 128)	\
)

#define PICYUYV(xin)						\
(								\
  UV(0, xin),						\
  PIC1(xin / 4 * 8 + 0, (xin & 3) * 2 + 0, pic0, xin * 2 + 0),	\
  PIC2(xin / 4 * 8 + 0, (xin & 3) * 2 + 1, pic0, xin * 2 + 1),	\
  UV(1, xin),						\
  PIC1(xin / 4 * 8 + 1, (xin & 3) * 2 + 0, pic1, xin * 2 + 0),	\
  PIC2(xin / 4 * 8 + 1, (xin & 3) * 2 + 1, pic1, xin * 2 + 1)	\
)


static void yuyvtopict(out, pic, width)
int *out;
unsigned char *pic;
int width;
{
    int i, j, k;
    unsigned char *pic0, *pic1;
    int *outy, *outc;
    int u, v, y;

    pic0 = pic;
    pic1 = pic + width;
    outy = out;
    outc = out + 64 * 4;
    for (i = 2; i > 0; i--) {
	for (j = 4; j > 0; j--) {
	    for (k = 0; k < 8; k++) {
		PICYUYV(k);
	    }
	    outc += 8;
	    outy += 16;
	    pic0 += 2 * width;
	    pic1 += 2 * width;
	}
	outy += 64 * 2 - 16 * 4;
    }
}

static void col221111(out, pic, width)
int *out;
unsigned char *pic;
int width;
{
    int i, j, k;
    unsigned char *pic0, *pic1;
    int *outy, *outc;
    int cr, cg, cb, y;

    pic0 = pic;
    pic1 = pic + width;
    outy = out;
    outc = out + 64 * 4;
    for (i = 2; i > 0; i--) {
	for (j = 4; j > 0; j--) {
	    for (k = 0; k < 8; k++) {
		PIC221111(k);
	    }
	    outc += 8;
	    outy += 16;
	    pic0 += 2 * width;
	    pic1 += 2 * width;
	}
	outy += 64 * 2 - 16 * 4;
    }
}