display.c

MPEG2视频编解码程序

      y2 = *py2++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = pixel[ytab[((y+y2)>>1)+3]|utab[u+3]|vtab[v+3]];
      *dst2++ = pixel[ytab[y2+15]|utab[u+15]|vtab[v+15]];

      y = *py++;
      y2 = *py2++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = pixel[ytab[((y+y2)>>1)+11]|utab[u+11]|vtab[v+11]];
      *dst2++ = pixel[ytab[y2+7]|utab[u+7]|vtab[v+7]];

      y = *py++;
      y2 = *py2++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = pixel[ytab[((y+y2)>>1)+1]|utab[u+1]|vtab[v+1]];
      *dst2++ = pixel[ytab[y2+13]|utab[u+13]|vtab[v+13]];

      y = *py++;
      y2 = *py2++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = pixel[ytab[((y+y2)>>1)+9]|utab[u+9]|vtab[v+9]];
      *dst2++ = pixel[ytab[y2+5]|utab[u+5]|vtab[v+5]];
    }

    py += coded_picture_width;
    py2 += coded_picture_width;
#ifdef _WIN32
    dst  = dst2 - 2*coded_picture_width;
    dst2 = dst  - coded_picture_width;
#else
    dst += coded_picture_width;
    dst2+= coded_picture_width;
#endif
    pu += chrom_width;
    pv += chrom_width;
  }
}

void init_dither(int bpp)
{
  int i, v;

  if ( bpp==8 )
  {
     dither_frame=ditherframe;
     dither_even =dithertop;
     dither_odd  =ditherbot;
  }
  else
     error("unsuported dither type");

  bpp/=8;
  if(!(dithered_image = (unsigned char *)malloc(bpp*coded_picture_width*
                                                coded_picture_height)))
    error("malloc failed");

  if(!(dithered_image2 = (unsigned char *)malloc(bpp*coded_picture_width*
                                                 coded_picture_height)))
    error("malloc failed");

  for (i=-8; i<256+8; i++)
  {
    v = i>>4;
    if (v<1)
      v = 1;
    else if (v>14)
      v = 14;
    ytab[i+8] = v<<4;
  }

  for (i=0; i<128+16; i++)
  {
    v = (i-40)>>4;
    if (v<0)
      v = 0;
    else if (v>3)
      v = 3;
    utab[i] = v<<2;
    vtab[i] = v;
  }

  for (i=0; i<256; i++)
     pixel[i]=i;
}

/*
 portable display function
*/
void display_second_field()
{
  display_image(dithered_image2);
}

#if 0
//
// This code does not work
//

static unsigned char uvtab[256*269+270];

static void ditherframe(src)
unsigned char *src[];
{
  int i,j;
  unsigned int uv;
  unsigned char *py,*pu,*pv,*dst;

  py = src[0];
  pu = src[1];
  pv = src[2];

#ifdef _WIN32
  dst = dithered_image+(coded_picture_height-1)*coded_picture_width;
#else
  dst = dithered_image;
#endif

  for (j=0; j<coded_picture_height; j+=4)
  {
    /* line j + 0 */
    for (i=0; i<coded_picture_width; i+=8)
    {
      uv = uvtab[(*pu++<<8)|*pv++];
      *dst++ = ytab[((*py++)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +8)<<4)|(uv>>4)];
      uv = uvtab[((*pu++<<8)|*pv++)+1028];
      *dst++ = ytab[((*py++ +2)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +10)<<4)|(uv>>4)];
      uv = uvtab[(*pu++<<8)|*pv++];
      *dst++ = ytab[((*py++)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +8)<<4)|(uv>>4)];
      uv = uvtab[((*pu++<<8)|*pv++)+1028];
      *dst++ = ytab[((*py++ +2)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +10)<<4)|(uv>>4)];
    }

    if (chroma_format==CHROMA420)
    {
      pu -= chrom_width;
      pv -= chrom_width;
    }
#ifdef _WIN32
    dst -= 2*coded_picture_width;
#endif

    /* line j + 1 */
    for (i=0; i<coded_picture_width; i+=8)
    {
      uv = uvtab[((*pu++<<8)|*pv++)+2056];
      *dst++ = ytab[((*py++ +12)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +4)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+3084];
      *dst++ = ytab[((*py++ +14)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +6)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+2056];
      *dst++ = ytab[((*py++ +12)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +4)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+3084];
      *dst++ = ytab[((*py++ +14)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +6)<<4)|(uv&15)];
    }
#ifdef _WIN32
    dst -= 2*coded_picture_width;
#endif

    /* line j + 2 */
    for (i=0; i<coded_picture_width; i+=8)
    {
      uv = uvtab[((*pu++<<8)|*pv++)+1542];
      *dst++ = ytab[((*py++ +3)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +11)<<4)|(uv>>4)];
      uv = uvtab[((*pu++<<8)|*pv++)+514];
      *dst++ = ytab[((*py++ +1)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +9)<<4)|(uv>>4)];
      uv = uvtab[((*pu++<<8)|*pv++)+1542];
      *dst++ = ytab[((*py++ +3)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +11)<<4)|(uv>>4)];
      uv = uvtab[((*pu++<<8)|*pv++)+514];
      *dst++ = ytab[((*py++ +1)<<4)|(uv&15)];
      *dst++ = ytab[((*py++ +9)<<4)|(uv>>4)];
    }

    if (chroma_format==CHROMA420)
    {
      pu -= chrom_width;
      pv -= chrom_width;
    }
#ifdef _WIN32
    dst -= 2*coded_picture_width;
#endif

    /* line j + 3 */
    for (i=0; i<coded_picture_width; i+=8)
    {
      uv = uvtab[((*pu++<<8)|*pv++)+3598];
      *dst++ = ytab[((*py++ +15)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +7)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+2570];
      *dst++ = ytab[((*py++ +13)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +5)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+3598];
      *dst++ = ytab[((*py++ +15)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +7)<<4)|(uv&15)];
      uv = uvtab[((*pu++<<8)|*pv++)+2570];
      *dst++ = ytab[((*py++ +13)<<4)|(uv>>4)];
      *dst++ = ytab[((*py++ +5)<<4)|(uv&15)];
    }
#ifdef _WIN32
    dst -= 2*coded_picture_width;
#endif
  }
}

static void dithertop(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  unsigned int y,uv1,uv2;
  unsigned char *py,*py2,*pu,*pv,*dst2;

  py = src[0];
  py2 = src[0] + (coded_picture_width<<1);
  pu = src[1];
  pv = src[2];
#ifdef _WIN32
  dst += (coded_picture_height-1)*coded_picture_width;
  dst2 = dst - coded_picture_width;
#else
  dst2 = dst + coded_picture_width;
#endif

  for (j=0; j<coded_picture_height; j+=4)
  {
    /* line j + 0, j + 1 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y = *py++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2];
      uv2 = uvtab[uv2+2056];
      *dst++  = ytab[((y)<<4)|(uv1&15)];
      *dst2++ = ytab[((((y + *py2++)>>1)+12)<<4)|(uv2>>4)];

      y = *py++;
      *dst++  = ytab[((y+8)<<4)|(uv1>>4)];
      *dst2++ = ytab[((((y + *py2++)>>1)+4)<<4)|(uv2&15)];

      y = *py++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+1028];
      uv2 = uvtab[uv2+3072];
      *dst++  = ytab[((y+2)<<4)|(uv1&15)];
      *dst2++ = ytab[((((y + *py2++)>>1)+14)<<4)|(uv2>>4)];

      y = *py++;
      *dst++  = ytab[((y+10)<<4)|(uv1>>4)];
      *dst2++ = ytab[((((y + *py2++)>>1)+6)<<4)|(uv2&15)];
    }

    py += coded_picture_width;

    if (j!=(coded_picture_height-4))
      py2 += coded_picture_width;
    else
      py2 -= coded_picture_width;

#ifdef _WIN32
    dst  = dst2 - 2*coded_picture_width;
    dst2 = dst  - coded_picture_width;
#else
    dst += coded_picture_width;
    dst2+= coded_picture_width;
#endif

    if (chroma_format==CHROMA420)
    {
      pu -= chrom_width;
      pv -= chrom_width;
    }
    else
    {
      pu += chrom_width;
      pv += chrom_width;
    }

    /* line j + 2, j + 3 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y = *py++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+1542];
      uv2 = uvtab[uv2+3598];
      *dst++  = ytab[((y+3)<<4)|(uv1&15)];
      *dst2++ = ytab[((((y + *py2++)>>1)+15)<<4)|(uv2>>4)];

      y = *py++;
      *dst++  = ytab[((y+11)<<4)|(uv1>>4)];
      *dst2++ = ytab[((((y + *py2++)>>1)+7)<<4)|(uv2&15)];

      y = *py++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+514];
      uv2 = uvtab[uv2+2570];
      *dst++  = ytab[((y+1)<<4)|(uv1&15)];
      *dst2++ = ytab[((((y + *py2++)>>1)+13)<<4)|(uv2>>4)];

      y = *py++;
      *dst++  = ytab[((y+9)<<4)|(uv1>>4)];
      *dst2++ = ytab[((((y + *py2++)>>1)+5)<<4)|(uv2&15)];
    }

    py += coded_picture_width;
    py2 += coded_picture_width;
#ifdef _WIN32
    dst  = dst2 - 2*coded_picture_width;
    dst2 = dst  - coded_picture_width;
#else
    dst += coded_picture_width;
    dst2+= coded_picture_width;
#endif
    pu += chrom_width;
    pv += chrom_width;
  }
}

static void ditherbot(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  unsigned int y2,uv1,uv2;
  unsigned char *py,*py2,*pu,*pv,*dst2;

  py = src[0] + coded_picture_width;
  py2 = py;
  pu = src[1] + chrom_width;
  pv = src[2] + chrom_width;
#ifdef _WIN32
  dst += (coded_picture_height-1)*coded_picture_width;
  dst2 = dst - coded_picture_width;
#else
  dst2 = dst + coded_picture_width;
#endif

  for (j=0; j<coded_picture_height; j+=4)
  {
    /* line j + 0, j + 1 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y2 = *py2++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2];
      uv2 = uvtab[uv2+2056];
      *dst++  = ytab[((((*py++ + y2)>>1))<<4)|(uv1&15)];
      *dst2++ = ytab[((y2+12)<<4)|(uv2>>4)];

      y2 = *py2++;
      *dst++  = ytab[((((*py++ + y2)>>1)+8)<<4)|(uv1>>4)];
      *dst2++ = ytab[((y2+4)<<4)|(uv2&15)];

      y2 = *py2++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+1028];
      uv2 = uvtab[uv2+3072];
      *dst++  = ytab[((((*py++ + y2)>>1)+2)<<4)|(uv1&15)];
      *dst2++ = ytab[((y2+14)<<4)|(uv2>>4)];

      y2 = *py2++;
      *dst++  = ytab[((((*py++ + y2)>>1)+10)<<4)|(uv1>>4)];
      *dst2++ = ytab[((y2+6)<<4)|(uv2&15)];
    }

    if (j==0)
      py -= coded_picture_width;
    else
      py += coded_picture_width;

    py2 += coded_picture_width;
#ifdef _WIN32
    dst  = dst2 - 2*coded_picture_width;
    dst2 = dst  - coded_picture_width;
#else
    dst += coded_picture_width;
    dst2+= coded_picture_width;
#endif

    if (chroma_format==CHROMA420)
    {
      pu -= chrom_width;
      pv -= chrom_width;
    }
    else
    {
      pu += chrom_width;
      pv += chrom_width;
    }

    /* line j + 2, j + 3 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y2 = *py2++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+1542];
      uv2 = uvtab[uv2+3598];
      *dst++  = ytab[((((*py++ + y2)>>1)+3)<<4)|(uv1&15)];
      *dst2++ = ytab[((y2+15)<<4)|(uv2>>4)];

      y2 = *py2++;
      *dst++  = ytab[((((*py++ + y2)>>1)+11)<<4)|(uv1>>4)];
      *dst2++ = ytab[((y2+7)<<4)|(uv2&15)];

      y2 = *py2++;
      uv2 = (*pu++<<8)|*pv++;
      uv1 = uvtab[uv2+514];
      uv2 = uvtab[uv2+2570];
      *dst++  = ytab[((((*py++ + y2)>>1)+1)<<4)|(uv1&15)];
      *dst2++ = ytab[((y2+13)<<4)|(uv2>>4)];

      y2 = *py2++;
      *dst++  = ytab[((((*py++ + y2)>>1)+9)<<4)|(uv1>>4)];
      *dst2++ = ytab[((y2+5)<<4)|(uv2&15)];
    }

    py += coded_picture_width;
    py2 += coded_picture_width;
#ifdef _WIN32
    dst  = dst2 - 2*coded_picture_width;
    dst2 = dst  - coded_picture_width;
#else
    dst += coded_picture_width;
    dst2+= coded_picture_width;
#endif
    pu += chrom_width;
    pv += chrom_width;
  }
}
void init_dither(int bpp)
{
  int i, j, v;
  unsigned char ctab[256+32];

  if ( bpp==8 )
  {
     dither_frame=ditherframe;
     dither_even =dithertop;
     dither_odd  =ditherbot;
  }
  else
     error("unsuported dither type");

  bpp/=8;
  if(!(dithered_image = (unsigned char *)malloc(bpp*coded_picture_width*
                                                coded_picture_height)))
    error("malloc failed");

  if(!(dithered_image2 = (unsigned char *)malloc(bpp*coded_picture_width*
                                                 coded_picture_height)))
    error("malloc failed");

  for (i=0; i<256; i++)
     pixel[i]=i;

  for (i=0; i<256+16; i++)
  {
    v = (i-8)>>4;
    if (v<2)
      v = 2;
    else if (v>14)
      v = 14;
    for (j=0; j<16; j++)
      ytab[16*i+j] = pixel[(v<<4)+j];
  }

  for (i=0; i<256+32; i++)
  {
    v = (i+48-128)>>5;
    if (v<0)
      v = 0;
    else if (v>3)
      v = 3;
    ctab[i] = v;
  }

  for (i=0; i<255+15; i++)
    for (j=0; j<255+15; j++)
      uvtab[256*i+j]=(ctab[i+16]<<6)|(ctab[j+16]<<4)|(ctab[i]<<2)|ctab[j];

}
#endif