svq1.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

  vlc_code_t *vlc;
  uint8_t    *list[63];
  uint32_t   *dst;
  const uint32_t *codebook;
  int	      entries[6];
  int	      i, j, m, n;
  int	      mean, stages;
  unsigned    x, y, width, height, level;
  uint32_t    n1, n2, n3, n4;

  /* initialize list for breadth first processing of vectors */
  list[0] = pixels;

  /* recursively process vector */
  for (i=0, m=1, n=1, level=5; i < n; i++) {
    SVQ1_PROCESS_VECTOR();

    /* destination address and vector size */
    dst = (uint32_t *) list[i];
    width = 1 << ((4 + level) /2);
    height = 1 << ((3 + level) /2);

    /* get number of stages (-1 skips vector, 0 for mean only) */
    bit_cache = get_bit_cache (bitbuf);

    vlc = &svq1_intra_vector_tables[level][bit_cache >> (32 - 7)];

    /* flush bits */
    stages	    = vlc->value;
    skip_bits(bitbuf,vlc->length);

    if (stages == -1) {
	for (y=0; y < height; y++) {
	  memset (&dst[y*(pitch / 4)], 0, width);
	}
      continue;		/* skip vector */
    }

    if ((stages > 0) && (level >= 4)) {
#ifdef DEBUG_SVQ1
    printf("Error (svq1_decode_block_intra): invalid vector: stages=%i level=%i\n",stages,level);
#endif
      return -1;	/* invalid vector */
    }

    /* get mean value for vector */
    bit_cache = get_bit_cache (bitbuf);

    if (bit_cache >= 0x25000000)
	vlc = &svq1_intra_mean_table_0[(bit_cache >> (32 - 8)) - 37];
    else if (bit_cache >= 0x03400000)
	vlc = &svq1_intra_mean_table_1[(bit_cache >> (32 - 10)) - 13];
    else if (bit_cache >= 0x00040000) 
	vlc = &svq1_intra_mean_table_2[(bit_cache >> (32 - 14)) - 1];
    else
	vlc = &svq1_intra_mean_table_3[bit_cache >> (32 - 20)];

    /* flush bits */
    mean	    = vlc->value;
    skip_bits(bitbuf,vlc->length);

    if (stages == 0) {
      for (y=0; y < height; y++) {
	memset (&dst[y*(pitch / 4)], mean, width);
      }
    } else {
      SVQ1_CALC_CODEBOOK_ENTRIES(svq1_intra_codebooks);
      SVQ1_DO_CODEBOOK_INTRA()
    }
  }

  return 0;
}

static int svq1_decode_block_non_intra (bit_buffer_t *bitbuf, uint8_t *pixels, int pitch ) {
  uint32_t    bit_cache;
  vlc_code_t *vlc;
  uint8_t    *list[63];
  uint32_t   *dst;
  const uint32_t *codebook;
  int	      entries[6];
  int	      i, j, m, n;
  int	      mean, stages;
  int	      x, y, width, height, level;
  uint32_t    n1, n2, n3, n4;

  /* initialize list for breadth first processing of vectors */
  list[0] = pixels;

  /* recursively process vector */
  for (i=0, m=1, n=1, level=5; i < n; i++) {
    SVQ1_PROCESS_VECTOR();

    /* destination address and vector size */
    dst = (uint32_t *) list[i];
    width = 1 << ((4 + level) /2);
    height = 1 << ((3 + level) /2);

    /* get number of stages (-1 skips vector, 0 for mean only) */
    bit_cache = get_bit_cache (bitbuf);

    vlc = &svq1_inter_vector_tables[level][bit_cache >> (32 - 6)];

    /* flush bits */
    stages	    = vlc->value;
    skip_bits(bitbuf,vlc->length);

    if (stages == -1) continue;	/* skip vector */

    if ((stages > 0) && (level >= 4)) {
#ifdef DEBUG_SVQ1
    printf("Error (svq1_decode_block_non_intra): invalid vector: stages=%i level=%i\n",stages,level);
#endif
      return -1;	/* invalid vector */
    }

    /* get mean value for vector */
    bit_cache = get_bit_cache (bitbuf);

    if (bit_cache >= 0x0B000000)
	vlc = &svq1_inter_mean_table_0[(bit_cache >> (32 - 8)) - 11];
    else if (bit_cache >= 0x01200000)
	vlc = &svq1_inter_mean_table_1[(bit_cache >> (32 - 12)) - 18];
    else if (bit_cache >= 0x002E0000) 
	vlc = &svq1_inter_mean_table_2[(bit_cache >> (32 - 15)) - 23];
    else if (bit_cache >= 0x00094000)
	vlc = &svq1_inter_mean_table_3[(bit_cache >> (32 - 18)) - 37];
    else if (bit_cache >= 0x00049000)
	vlc = &svq1_inter_mean_table_4[(bit_cache >> (32 - 20)) - 73];
    else
	vlc = &svq1_inter_mean_table_5[bit_cache >> (32 - 22)];

    /* flush bits */
    mean	    = vlc->value;
    skip_bits(bitbuf,vlc->length);

    SVQ1_CALC_CODEBOOK_ENTRIES(svq1_inter_codebooks);
    SVQ1_DO_CODEBOOK_NONINTRA()
  }
  return 0;
}

static int svq1_decode_motion_vector (bit_buffer_t *bitbuf, svq1_pmv_t *mv, svq1_pmv_t **pmv) {
  uint32_t    bit_cache;
  vlc_code_t *vlc;
  int	      diff, sign;
  int	      i;

  for (i=0; i < 2; i++) {

    /* get motion code */
    bit_cache = get_bit_cache (bitbuf);

    if (!(bit_cache & 0xFFE00000))
      return -1;	/* invalid vlc code */

    if (bit_cache & 0x80000000) {
      diff = 0;

      /* flush bit */
      skip_bits(bitbuf,1);

    } else {
      if (bit_cache >= 0x06000000) {
        vlc = &svq1_motion_table_0[(bit_cache >> (32 - 7)) - 3];
      } else {
        vlc = &svq1_motion_table_1[(bit_cache >> (32 - 12)) - 2];
      }

      /* decode motion vector differential */
      sign = (int) (bit_cache << (vlc->length - 1)) >> 31;
      diff = (vlc->value ^ sign) - sign;

      /* flush bits */
      skip_bits(bitbuf,vlc->length);
    }

    /* add median of motion vector predictors and clip result */
    if (i == 1)
      mv->y = ((diff + MEDIAN(pmv[0]->y, pmv[1]->y, pmv[2]->y)) << 26) >> 26;
    else
      mv->x = ((diff + MEDIAN(pmv[0]->x, pmv[1]->x, pmv[2]->x)) << 26) >> 26;
  }

  return 0;
}

static void svq1_skip_block (uint8_t *current, uint8_t *previous, int pitch, int x, int y) {
  uint8_t *src;
  uint8_t *dst;
  int	   i;

  src = &previous[x + y*pitch];
  dst = current;

  for (i=0; i < 16; i++) {
    memcpy (dst, src, 16);
    src += pitch;
    dst += pitch;
  }
}

static int svq1_motion_inter_block (MpegEncContext *s, bit_buffer_t *bitbuf,
			       uint8_t *current, uint8_t *previous, int pitch,
			       svq1_pmv_t *motion, int x, int y) {
  uint8_t    *src;
  uint8_t    *dst;
  svq1_pmv_t  mv;
  svq1_pmv_t *pmv[3];
  int	      result;

  /* predict and decode motion vector */
  pmv[0] = &motion[0];
  if (y == 0) {
    pmv[1] =
    pmv[2] = pmv[0];
  }
  else {
    pmv[1] = &motion[(x / 8) + 2];
    pmv[2] = &motion[(x / 8) + 4];
  }

  result = svq1_decode_motion_vector (bitbuf, &mv, pmv);

  if (result != 0)
    return result;

  motion[0].x		=
  motion[(x / 8) + 2].x	=
  motion[(x / 8) + 3].x	= mv.x;
  motion[0].y		=
  motion[(x / 8) + 2].y	=
  motion[(x / 8) + 3].y	= mv.y;

  src = &previous[(x + (mv.x >> 1)) + (y + (mv.y >> 1))*pitch];
  dst = current;

  s->dsp.put_pixels_tab[0][((mv.y & 1) << 1) | (mv.x & 1)](dst,src,pitch,16);

  return 0;
}

static int svq1_motion_inter_4v_block (MpegEncContext *s, bit_buffer_t *bitbuf,
				  uint8_t *current, uint8_t *previous, int pitch,
				  svq1_pmv_t *motion,int x, int y) {
  uint8_t    *src;
  uint8_t    *dst;
  svq1_pmv_t  mv;
  svq1_pmv_t *pmv[4];
  int	      i, result;

  /* predict and decode motion vector (0) */
  pmv[0] = &motion[0];
  if (y == 0) {
    pmv[1] =
    pmv[2] = pmv[0];
  }
  else {
    pmv[1] = &motion[(x / 8) + 2];
    pmv[2] = &motion[(x / 8) + 4];
  }

  result = svq1_decode_motion_vector (bitbuf, &mv, pmv);

  if (result != 0)
    return result;

  /* predict and decode motion vector (1) */
  pmv[0] = &mv;
  if (y == 0) {
    pmv[1] =
    pmv[2] = pmv[0];
  }
  else {
    pmv[1] = &motion[(x / 8) + 3];
  }
  result = svq1_decode_motion_vector (bitbuf, &motion[0], pmv);

  if (result != 0)
    return result;

  /* predict and decode motion vector (2) */
  pmv[1] = &motion[0];
  pmv[2] = &motion[(x / 8) + 1];

  result = svq1_decode_motion_vector (bitbuf, &motion[(x / 8) + 2], pmv);

  if (result != 0)
    return result;

  /* predict and decode motion vector (3) */
  pmv[2] = &motion[(x / 8) + 2];
  pmv[3] = &motion[(x / 8) + 3];

  result = svq1_decode_motion_vector (bitbuf, pmv[3], pmv);

  if (result != 0)
    return result;

  /* form predictions */
  for (i=0; i < 4; i++) {
    src = &previous[(x + (pmv[i]->x >> 1)) + (y + (pmv[i]->y >> 1))*pitch];