display.c

MPEG2视频编解码算法方面的源代码(包括编码和解码)

{
#ifdef SH_MEM
  if (Shmem_Flag)
  {
    XShmDetach(Display_Ptr, &Shminfo1);
    XDestroyImage(Ximage_Ptr);
    shmdt(Shminfo1.shmaddr);
    if (!progressive_sequence)
    {
      XShmDetach(Display_Ptr, &Shminfo2);
      XDestroyImage(Ximage_Ptr2);
      shmdt(Shminfo2.shmaddr);
    }
  }
#endif
}

static void Display_Image(Ximage_Ptr,Dithered_Image)
XImage *Ximage_Ptr;
unsigned char *Dithered_Image;
{
  /* display dithered image */
#ifdef SH_MEM
  if (Shmem_Flag)
  {
    XShmPutImage(Display_Ptr, Window_Instance, GC_Instance, Ximage_Ptr, 
       	         0, 0, 0, 0, Ximage_Ptr->width, Ximage_Ptr->height, True);
    XFlush(Display_Ptr);
      
    while (1)
    {
      XEvent xev;
	
      XNextEvent(Display_Ptr, &xev);
      if (xev.type == CompletionType)
        break;
    }
  }
  else 
#endif
  {
    Ximage_Ptr->data = (char *) Dithered_Image; 
    Ximage_Ptr->depth=8;
    XPutImage(Display_Ptr, Window_Instance, GC_Instance, Ximage_Ptr, 0, 0, 0, 0, Ximage_Ptr->width, Ximage_Ptr->height);
  }
}

void Display_Second_Field()
{
  Display_Image(Ximage_Ptr2,Dithered_Image2);
}

/* 4x4 ordered dither
 *
 * threshold pattern:
 *   0  8  2 10
 *  12  4 14  6
 *   3 11  1  9
 *  15  7 13  5
 */

void Initialize_Dither_Matrix()
{
  int i, v;

  for (i=-8; i<256+8; i++)
  {
    v = i>>4;
    if (v<1)
      v = 1;
    else if (v>14)
      v = 14;
    Y_Table[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;
    Cb_Table[i] = v<<2;
    Cr_Table[i] = v;
  }
}

void dither(src)
unsigned char *src[];
{
  /* should this test only the display flag, not progressive_sequence ? --CF */
  /* CHANGE 95/05/13: progressive_sequence -> progressive_frame */

  if( progressive_frame || Display_Progressive_Flag)
    Dither_Frame(src);
  else
  {
    if ((picture_structure==FRAME_PICTURE && top_field_first) || picture_structure==BOTTOM_FIELD)
    {
      /* top field first */
      if (chroma_format==CHROMA420 && hiQdither)
      {
        Dither_Top_Field420(src,Dithered_Image);
        Dither_Bottom_Field420(src,Dithered_Image2);
      }
      else
      {
        Dither_Top_Field(src,Dithered_Image);
        Dither_Bottom_Field(src,Dithered_Image2);
      }
    }
    else
    {
      /* bottom field first */
      if (chroma_format==CHROMA420 && hiQdither)
      {
        Dither_Bottom_Field420(src,Dithered_Image);
        Dither_Top_Field420(src,Dithered_Image2);
      }
      else
      {
        Dither_Bottom_Field(src,Dithered_Image);
        Dither_Top_Field(src,Dithered_Image2);
      }
    }
  }

  Display_Image(Ximage_Ptr,Dithered_Image);
}

static void Dither_Frame(src)
unsigned char *src[];
{
  int i,j;
  int y,u,v;
  unsigned char *py,*pu,*pv,*dst;

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

  for (j=0; j<Coded_Picture_Height; j+=4)
  {
    /* line j + 0 */
    for (i=0; i<Coded_Picture_Width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y]|Cb_Table[u]|Cr_Table[v]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+8]|Cb_Table[u+8]|Cr_Table[v+8]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+2]|Cb_Table[u+2]|Cr_Table[v+2]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+10]|Cb_Table[u+10]|Cr_Table[v+10]];
    }

    if (chroma_format==CHROMA420)
    {
      pu -= Chroma_Width;
      pv -= Chroma_Width;
    }

    /* line j + 1 */
    for (i=0; i<Coded_Picture_Width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+12]|Cb_Table[u+12]|Cr_Table[v+12]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+4]|Cb_Table[u+4]|Cr_Table[v+4]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+14]|Cb_Table[u+14]|Cr_Table[v+14]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+6]|Cb_Table[u+6]|Cr_Table[v+6]];
    }

    /* line j + 2 */
    for (i=0; i<Coded_Picture_Width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+3]|Cb_Table[u+3]|Cr_Table[v+3]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+11]|Cb_Table[u+11]|Cr_Table[v+11]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+1]|Cb_Table[u+1]|Cr_Table[v+1]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+9]|Cb_Table[u+9]|Cr_Table[v+9]];
    }

    if (chroma_format==CHROMA420)
    {
      pu -= Chroma_Width;
      pv -= Chroma_Width;
    }

    /* line j + 3 */
    for (i=0; i<Coded_Picture_Width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+15]|Cb_Table[u+15]|Cr_Table[v+15]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+7]|Cb_Table[u+7]|Cr_Table[v+7]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = Pixel[Y_Table[y+13]|Cb_Table[u+13]|Cr_Table[v+13]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = Pixel[Y_Table[y+5]|Cb_Table[u+5]|Cr_Table[v+5]];
    }
  }

}

static void Dither_Top_Field(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  int y,Y2,u,v;
  unsigned char *py,*Y2_ptr,*pu,*pv,*dst2;

  py = src[0];
  Y2_ptr = src[0] + (Coded_Picture_Width<<1);
  pu = src[1];
  pv = src[2];
  dst2 = dst + Coded_Picture_Width;

  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++;
      Y2 = *Y2_ptr++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = Pixel[Y_Table[y]|Cb_Table[u]|Cr_Table[v]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+12]|Cb_Table[u+12]|Cr_Table[v+12]];

      y = *py++;
      Y2 = *Y2_ptr++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = Pixel[Y_Table[y+8]|Cb_Table[u+8]|Cr_Table[v+8]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+4]|Cb_Table[u+4]|Cr_Table[v+4]];

      y = *py++;
      Y2 = *Y2_ptr++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = Pixel[Y_Table[y+2]|Cb_Table[u+2]|Cr_Table[v+2]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+14]|Cb_Table[u+14]|Cr_Table[v+14]];

      y = *py++;
      Y2 = *Y2_ptr++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = Pixel[Y_Table[y+10]|Cb_Table[u+10]|Cr_Table[v+10]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+6]|Cb_Table[u+6]|Cr_Table[v+6]];
    }

    py += Coded_Picture_Width;

    if (j!=(Coded_Picture_Height-4))
      Y2_ptr += Coded_Picture_Width;
    else
      Y2_ptr -= Coded_Picture_Width;

    dst += Coded_Picture_Width;
    dst2 += Coded_Picture_Width;

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

    /* line j + 2, j + 3 */
    for (i=0; i<Coded_Picture_Width; i+=4)
    {
      y = *py++;
      Y2 = *Y2_ptr++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = Pixel[Y_Table[y+3]|Cb_Table[u+3]|Cr_Table[v+3]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+15]|Cb_Table[u+15]|Cr_Table[v+15]];

      y = *py++;
      Y2 = *Y2_ptr++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = Pixel[Y_Table[y+11]|Cb_Table[u+11]|Cr_Table[v+11]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+7]|Cb_Table[u+7]|Cr_Table[v+7]];

      y = *py++;
      Y2 = *Y2_ptr++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = Pixel[Y_Table[y+1]|Cb_Table[u+1]|Cr_Table[v+1]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+13]|Cb_Table[u+13]|Cr_Table[v+13]];

      y = *py++;
      Y2 = *Y2_ptr++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = Pixel[Y_Table[y+9]|Cb_Table[u+9]|Cr_Table[v+9]];
      *dst2++ = Pixel[Y_Table[((y+Y2)>>1)+5]|Cb_Table[u+5]|Cr_Table[v+5]];
    }

    py += Coded_Picture_Width;
    Y2_ptr += Coded_Picture_Width;
    dst += Coded_Picture_Width;
    dst2 += Coded_Picture_Width;
    pu += Chroma_Width;
    pv += Chroma_Width;
  }
}

static void Dither_Bottom_Field(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  int y,Y2,u,v;
  unsigned char *py,*Y2_ptr,*pu,*pv,*dst2;

  py = src[0] + Coded_Picture_Width;
  Y2_ptr = py;
  pu = src[1] + Chroma_Width;
  pv = src[2] + Chroma_Width;
  dst2 = dst + Coded_Picture_Width;

  for (j=0; j<Coded_Picture_Height; j+=4)
  {
    /* line j + 0, j + 1 */
    for (i=0; i<Coded_Picture_Width; i+=4)