gspcadecoder.c

来自「Linux下很强大的万能USB摄像头驱动。解压后」· C语言 代码 · 共 2,167 行 · 第 1/5 页

	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255, 255, 255, 255, 255,
	255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
	255
    };
    // abs_clamp15[19 + i] = min(abs(i), 15)
    const static int abs_clamp15[] =
	{ 15, 15, 15, 15, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3,
	2, 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 15, 15,
	15
    };
    // diff_encoding[256 + i] = ...
    const static int diff_encoding[] =
	{ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7,
	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 5, 5, 5, 5, 5, 5, 5, 5, 5,
	5, 5, 5, 5, 5, 3, 3,
	3, 3, 1, 1, 0, 2, 2, 4, 4, 4, 4, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
	6, 6, 6, 6, 6, 6
    };


    int block;

    int bitfill = 0;
    int xwidth = width + 6;
    int off_up_right = 2 - 2 * xwidth;
    int off_up_left = -2 - 2 * xwidth;

    int pixel_U = 0, saved_pixel_UR = 0;
    int pixel_x = 0, pixel_y = 2;

    unsigned char *output_ptr = outbuf;

    memset(i_hits, 0, sizeof(i_hits));
    memset(accum, 0, sizeof(accum));

    memcpy(outbuf + xwidth * 2 + 3, inbuf + 0x14, width);
    memcpy(outbuf + xwidth * 3 + 3, inbuf + 0x14 + width, width);

    input_ptr = inbuf + 0x14 + width * 2;
    output_ptr = outbuf + (xwidth) * 4 + 3;

    bit_bucket = 0;

    for (block = 0; block < ((height - 2) * width) / 32; ++block) {
	int b_it, var_7 = 0;
	int cur_byte;

	refill(&bitfill);

	cur_byte = (bit_bucket >> (bitfill & 7)) & 0xff;

	if ((cur_byte & 0x80) == 0) {
	    var_7 = 0;
	    bitfill--;
	} else if ((cur_byte & 0xC0) == 0x80) {
	    var_7 = 1;
	    bitfill -= 2;
	} else if ((cur_byte & 0xc0) == 0xc0) {
	    var_7 = 2;
	    bitfill -= 2;
	}

	for (b_it = 0; b_it < 32; b_it++) {
	    int index;
	    int pixel_L, pixel_UR, pixel_UL;
	    int multiplier;
	    int dL, dC, dR;

	    int gkw;		// God knows what

	    refill(&bitfill);
	    cur_byte = bit_bucket >> (bitfill & 7) & 0xff;

	    pixel_L = output_ptr[-2];
	    pixel_UR = output_ptr[off_up_right];
	    pixel_UL = output_ptr[off_up_left];

	    dL = diff_encoding[0x100 + pixel_UL - pixel_L];
	    dC = diff_encoding[0x100 + pixel_U - pixel_UL];
	    dR = diff_encoding[0x100 + pixel_UR - pixel_U];

	    if (pixel_x < 2) {
		pixel_L = pixel_UL = pixel_U = output_ptr[-xwidth * 2];
		pixel_UR = output_ptr[off_up_right];
		dL = dC = 0;
		dR = diff_encoding[0x100 + pixel_UR - pixel_U];
	    } else if (pixel_x > width - 3)
		dR = 0;

	    multiplier = 4;
	    index = dR + dC * 8 + dL * 64;

	    if (pixel_L + pixel_U * 2 <= 144
		&& (pixel_y & 1) == 0
		&& (b_it & 3) == 0 && (dR < 5) && (dC < 5) && (dL < 5)) {

		multiplier = 1;

	    } else if (pixel_L <= 48
		       && dL <= 4 && dC <= 4 && dL >= 1 && dC >= 1) {
		multiplier = 2;

	    } else if (var_7 == 1) {
		multiplier = 2;

	    } else if (dC + dL >= 11 || var_7 == 2) {
		multiplier = 8;
	    }

	    if (i_hits[index] < 7) {
		bitfill -= nbits_A[cur_byte];
		gkw = tab_A[cur_byte];
		if (gkw == 0xfe)
		    gkw = fun_A(&bitfill);

	    } else if (i_hits[index] >= accum[index]) {
		bitfill -= nbits_B[cur_byte];
		gkw = tab_B[cur_byte];
		if (cur_byte == 0)
		    gkw = fun_B(&bitfill);

	    } else if (i_hits[index] * 2 >= accum[index]) {
		bitfill -= nbits_C[cur_byte];
		gkw = tab_C[cur_byte];
		if (cur_byte < 2)
		    gkw = fun_C(&bitfill, gkw);

	    } else if (i_hits[index] * 4 >= accum[index]) {
		bitfill -= nbits_D[cur_byte];
		gkw = tab_D[cur_byte];
		if (cur_byte < 4)
		    gkw = fun_D(&bitfill, gkw);

	    } else if (i_hits[index] * 8 >= accum[index]) {
		gkw = fun_E(cur_byte, &bitfill);

	    } else {
		gkw = fun_F(cur_byte, &bitfill);
	    }

	    if (gkw == 0xff)
		return -3;

	    {
		int tmp1, tmp2;
		tmp1 = (pixel_U + pixel_L) * 3 - pixel_UL * 2;
		tmp1 += (tmp1 < 0) ? 3 : 0;
		tmp2 = a_curve[19 + gkw] * multiplier;
		tmp2 += (tmp2 < 0) ? 1 : 0;

		*(output_ptr++) =
		    clamp0_255[0x100 + (tmp1 >> 2) - (tmp2 >> 1)];
	    }

	    pixel_U = saved_pixel_UR;
	    saved_pixel_UR = pixel_UR;

	    if (++pixel_x == width) {
		output_ptr += 6;
		pixel_x = 0;
		pixel_y++;
	    }

	    accum[index] += abs_clamp15[19 + gkw];

	    if (i_hits[index]++ == 15) {
		i_hits[index] = 8;
		accum[index] /= 2;
	    }

	}

    }

    return 0;
}
static
void decode_spca561(unsigned char *inbuf, char *outbuf, int width,
		    int height)
{
    int i;
    static char tmpbuf[650 * 490];

    if (internal_spca561_decode(width, height, inbuf, tmpbuf) == 0) {
	for (i = 0; i < height; i++)
	    memcpy(outbuf + i * width,
		   tmpbuf + (i + 2) * (width + 6) + 3, width);
    }

}

/****************************************************************/
/**************       huffman decoder             ***************/
/****************************************************************/

/*need to be on init jpeg */
static struct comp comp_template[MAXCOMP] = {
    {0x01, 0x22, 0x00},
    {0x02, 0x11, 0x01},
    {0x03, 0x11, 0x01},
    {0x00, 0x00, 0x00}
};

/* deprecated set by webcam now in spca50x */
//static struct scan dscans[MAXCOMP];
//static unsigned char quant[3][64];
//static struct in in;
//int dquant[3][64];
//static struct jpginfo info;
/* table de Huffman global for all */
static struct dec_hufftbl dhuff[4];
#define dec_huffdc (dhuff + 0)
#define dec_huffac (dhuff + 2)
#define M_RST0	0xd0


static int fillbits(struct in *, int, unsigned int);
static int dec_rec2(struct in *, struct dec_hufftbl *, int *, int, int);

static int fillbits(struct in *in, int le, unsigned int bi)
{
    int b;
    int m;
    if (in->marker) {
	if (le <= 16)
	    in->bits = bi << 16, le += 16;
	return le;
    }
    while (le <= 24) {
	b = *in->p++;
	if (in->omitescape) {
	    if (b == 0xff && (m = *in->p++) != 0) {
		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;
}

#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 void dec_initscans(struct dec_data *decode)
{
    struct jpginfo *info = &decode->info;
    struct scan *dscans = decode->dscans;
    int i;
    info->ns = 3;		// HARDCODED  here
    info->nm = info->dri + 1;	// macroblock count
    info->rm = M_RST0;
    for (i = 0; i < info->ns; i++)
	dscans[i].dc = 0;
}
static int dec_readmarker(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;
}

static int dec_checkmarker(struct dec_data *decode)
{
    struct jpginfo *info = &decode->info;
    struct scan *dscans = decode->dscans;
    struct in *in = &decode->in;
    int i;

    if (dec_readmarker(in) != info->rm)
	return -1;
    info->nm = info->dri;
    info->rm = (info->rm + 1) & ~0x08;
    for (i = 0; i < info->ns; i++)
	dscans[i].dc = 0;
    return 0;
}
static
void
jpeg_reset_input_context(struct dec_data *decode, unsigned char *buf,
			 int oescap)
{
    /* set input context */
    struct in *in = &decode->in;
    in->p = buf;
    in->omitescape = oescap;
    in->left = 0;
    in->bits = 0;
    in->marker = 0;
}
static int
dec_rec2(struct in *in, struct dec_hufftbl *hu, int *runp, int c, int i)
{
    int le, bi;

    le = in->left;
    bi = in->bits;
    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					\
    )					\
)

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

    memset(dct, 0, n * 64 * sizeof(*dct));
    le = in->left;
    bi = in->bits;

    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;