display.c

该源码可以将mpeg、mpg和m2v格式的视频文件解码成yuv、ppm、tga等格式文件

void exit_display()
{
#ifdef SH_MEM
  if (shmem_flag)
  {
    XShmDetach(display, &shminfo1);
    XDestroyImage(ximage);
    shmdt(shminfo1.shmaddr);
    if (!prog_seq)
    {
      XShmDetach(display, &shminfo2);
      XDestroyImage(ximage2);
      shmdt(shminfo2.shmaddr);
    }
  }
#endif
}

static void display_image(ximage,dithered_image)
XImage *ximage;
unsigned char *dithered_image;
{
  /* display dithered image */
#ifdef SH_MEM
  if (shmem_flag)
  {
    XShmPutImage(display, window, gc, ximage, 
       	         0, 0, 0, 0, ximage->width, ximage->height, True);
    XFlush(display);
      
    while (1)
    {
      XEvent xev;
	
      XNextEvent(display, &xev);
      if (xev.type == CompletionType)
        break;
    }
  }
  else 
#endif
  {
    ximage->data = (char *) dithered_image; 
    XPutImage(display, window, gc, ximage, 0, 0, 0, 0, ximage->width, ximage->height);
  }
}

void display_second_field()
{
  display_image(ximage2,dithered_image2);
}

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

void init_dither()
{
  int i, v;

  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;
  }
}

void dither(src)
unsigned char *src[];
{
  if (prog_seq)
    ditherframe(src);
  else
  {
    if ((pict_struct==FRAME_PICTURE && topfirst) || pict_struct==BOTTOM_FIELD)
    {
      /* top field first */
      if (chroma_format==CHROMA420 && hiQdither)
      {
        dithertop420(src,dithered_image);
        ditherbot420(src,dithered_image2);
      }
      else
      {
        dithertop(src,dithered_image);
        ditherbot(src,dithered_image2);
      }
    }
    else
    {
      /* bottom field first */
      if (chroma_format==CHROMA420 && hiQdither)
      {
        ditherbot420(src,dithered_image);
        dithertop420(src,dithered_image2);
      }
      else
      {
        ditherbot(src,dithered_image);
        dithertop(src,dithered_image2);
      }
    }
  }

  display_image(ximage,dithered_image);
}

static void ditherframe(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[ytab[y]|utab[u]|vtab[v]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+8]|utab[u+8]|vtab[v+8]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+2]|utab[u+2]|vtab[v+2]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+10]|utab[u+10]|vtab[v+10]];
    }

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

    /* line j + 1 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+12]|utab[u+12]|vtab[v+12]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+4]|utab[u+4]|vtab[v+4]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+14]|utab[u+14]|vtab[v+14]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+6]|utab[u+6]|vtab[v+6]];
    }

    /* line j + 2 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+3]|utab[u+3]|vtab[v+3]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+11]|utab[u+11]|vtab[v+11]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+1]|utab[u+1]|vtab[v+1]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+9]|utab[u+9]|vtab[v+9]];
    }

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

    /* line j + 3 */
    for (i=0; i<coded_picture_width; i+=4)
    {
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+15]|utab[u+15]|vtab[v+15]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+7]|utab[u+7]|vtab[v+7]];
      y = *py++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++ = pixel[ytab[y+13]|utab[u+13]|vtab[v+13]];
      y = *py++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++ = pixel[ytab[y+5]|utab[u+5]|vtab[v+5]];
    }
  }

}

static void dithertop(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  int y,y2,u,v;
  unsigned char *py,*py2,*pu,*pv,*dst2;

  py = src[0];
  py2 = 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 = *py2++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = pixel[ytab[y]|utab[u]|vtab[v]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+12]|utab[u+12]|vtab[v+12]];

      y = *py++;
      y2 = *py2++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = pixel[ytab[y+8]|utab[u+8]|vtab[v+8]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+4]|utab[u+4]|vtab[v+4]];

      y = *py++;
      y2 = *py2++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = pixel[ytab[y+2]|utab[u+2]|vtab[v+2]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+14]|utab[u+14]|vtab[v+14]];

      y = *py++;
      y2 = *py2++;
      if (chroma_format==CHROMA444)
      {
        u = *pu++ >> 1;
        v = *pv++ >> 1;
      }
      *dst++  = pixel[ytab[y+10]|utab[u+10]|vtab[v+10]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+6]|utab[u+6]|vtab[v+6]];
    }

    py += coded_picture_width;

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

    dst += coded_picture_width;
    dst2 += coded_picture_width;

    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++;
      y2 = *py2++;
      u = *pu++ >> 1;
      v = *pv++ >> 1;
      *dst++  = pixel[ytab[y+3]|utab[u+3]|vtab[v+3]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+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+11]|utab[u+11]|vtab[v+11]];
      *dst2++ = pixel[ytab[((y+y2)>>1)+7]|utab[u+7]|vtab[v+7]];

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

    py += coded_picture_width;
    py2 += coded_picture_width;
    dst += coded_picture_width;
    dst2 += coded_picture_width;
    pu += chrom_width;
    pv += chrom_width;
  }
}

static void ditherbot(src,dst)
unsigned char *src[];
unsigned char *dst;
{
  int i,j;
  int y,y2,u,v;
  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;
  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++;