display.c

H.263的压缩算法

/************************************************************************
 *
 *  display.c, X11 interface for tmndecode (H.263 decoder)
 *  Copyright (C) 1995, 1996  Telenor R&D, Norway
 *
 *  Contacts:
 *  Robert Danielsen                  <[e-mail]>
 *
 *  Telenor Research and Development  http://www.nta.no/brukere/DVC/
 *  P.O.Box 83                        tel.:   [phone]
 *  N-2007 Kjeller, Norway            fax.:   [phone]
 *
 *  Copyright (C) 1997  University of BC, Canada
 *  Modified by: Michael Gallant <[e-mail]>
 *               Guy Cote <[e-mail]>
 *               Berna Erol <[e-mail]>
 *               
 *  Contacts:
 *  Michael Gallant                   <[e-mail]>
 *
 *  UBC Image Processing Laboratory   http://www.ee.ubc.ca/image
 *  2356 Main Mall                    tel.: [phone]
 *  Vancouver BC Canada V6T1Z4        fax.: [phone]
 *
 ************************************************************************/

/* Disclaimer of Warranty
 * 
 * These software programs are available to the user without any license fee
 * or royalty on an "as is" basis. The University of British Columbia
 * disclaims any and all warranties, whether express, implied, or
 * statuary, including any implied warranties or merchantability or of
 * fitness for a particular purpose.  In no event shall the
 * copyright-holder be liable for any incidental, punitive, or
 * consequential damages of any kind whatsoever arising from the use of
 * these programs.
 * 
 * This disclaimer of warranty extends to the user of these programs and
 * user's customers, employees, agents, transferees, successors, and
 * assigns.
 * 
 * The University of British Columbia does not represent or warrant that the
 * programs furnished hereunder are free of infringement of any
 * third-party patents.
 * 
 * Commercial implementations of H.263, including shareware, are subject to
 * royalty fees to patent holders.  Many of these patents are general
 * enough such that they are unavoidable regardless of implementation
 * design.
 * 
 */


/* based on mpeg2decode, (C) 1994, MPEG Software Simulation Group and
 * mpeg2play, (C) 1994 Stefan Eckart <[e-mail]>
 * 
 */

/* the Xlib interface is closely modeled after mpeg_play 2.0 by the
 * Berkeley Plateau Research Group */

#ifdef DISPLAY

#include <stdio.h>
#include <stdlib.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>

#include "config.h"
#include "tmndec.h"
#include "global.h"

/* private prototypes */
static void display_image _ANSI_ARGS_ ((XImage * ximage, unsigned char *dithered_image));

/* display related data */
unsigned long wpixel[3];
static unsigned char *dithered_image;

/* X11 related variables */
static Display *display;
static Window window;
static GC gc;
static int dpy_depth;

XImage *ximage;

unsigned char pixel[256];

#ifdef SH_MEM

#include <sys/ipc.h>
#include <sys/shm.h>
#include <X11/extensions/XShm.h>

extern int XShmQueryExtension _ANSI_ARGS_ ((Display * dpy));
extern int XShmGetEventBase _ANSI_ARGS_ ((Display * dpy));

static int HandleXError _ANSI_ARGS_ ((Display * dpy, XErrorEvent * event));
static void InstallXErrorHandler _ANSI_ARGS_ ((void));
static void DeInstallXErrorHandler _ANSI_ARGS_ ((void));

static int shmem_flag;
static XShmSegmentInfo shminfo1, shminfo2;
static int gXErrorFlag;
static int CompletionType = -1;

static int HandleXError (dpy, event)
  Display *dpy;
  XErrorEvent *event;
{
  gXErrorFlag = 1;

  return 0;
}

static void InstallXErrorHandler ()
{
  XSetErrorHandler (HandleXError);
  XFlush (display);
}

static void DeInstallXErrorHandler ()
{
  XSetErrorHandler (NULL);
  XFlush (display);
}

#endif

/* connect to server, create and map window, allocate colors and (shared)
 * memory */
void init_display (name)
  char *name;
{
  int crv, cbu, cgu, cgv;
  int y, u, v, r, g, b;
  int i;
  char dummy;
  int screen;
  Visual *visual;
  int dpy_class;
  Colormap cmap;
  int private;
  XColor xcolor;
  unsigned int fg, bg;
  char *hello = "H.263 Display";
  XSizeHints hint;
  XEvent xev;
  XSetWindowAttributes xswa;
  unsigned long tmp_pixel;
  unsigned int mask;

  display = XOpenDisplay (name);

  if (display == NULL)
    error ("Can not open display\n");

  screen = DefaultScreen (display);

  visual = DefaultVisual (display, screen);
  dpy_depth = DefaultDepth (display, screen);
  dpy_class = visual->class;

  if (!((dpy_class == TrueColor && dpy_depth == 32)
        || (dpy_class == TrueColor && dpy_depth == 24)
        || (dpy_class == TrueColor && dpy_depth == 16)
        || (dpy_class == PseudoColor && dpy_depth == 8)))
    error ("requires 8 bit PseudoColor or 16/24/32 bit TrueColor display\n");

  if (dpy_class == TrueColor && dpy_depth == 32)
    printf ("TrueColor : 32 bit colordepth\n");
  if (dpy_class == TrueColor && dpy_depth == 24)
    printf ("TrueColor : 24 bit colordepth\n");
  if (dpy_class == TrueColor && dpy_depth == 16)
    printf ("TrueColor : 16 bit colordepth\n");
  if (dpy_class == PseudoColor && dpy_depth == 8)
    printf ("PseudoColor : 8 bit colordepth, 4x4 ordered dither\n");

  /* width and height of the display window */
  if (expand)
  {
    hint.min_width = hint.max_width = hint.width = 2 * horizontal_size;
    hint.min_height = hint.max_height = hint.height = 2 * vertical_size;
  } else
  {
    hint.min_width = hint.max_width = hint.width = horizontal_size;
    hint.min_height = hint.max_height = hint.height = vertical_size;
  }

  hint.flags = PSize | PMinSize | PMaxSize;

  /* Get some colors */

  bg = WhitePixel (display, screen);
  fg = BlackPixel (display, screen);

  /* Make the window */
  mask = CWBackPixel | CWBorderPixel;
  if (dpy_depth == 32 || dpy_depth == 24 || dpy_depth == 16)
  {
    mask |= CWColormap;
    xswa.colormap = XCreateColormap (display, DefaultRootWindow (display),
                                     visual, AllocNone);
  }
  xswa.background_pixel = bg;
  xswa.border_pixel = fg;
  window = XCreateWindow (display, DefaultRootWindow (display),
                          hint.x, hint.y, hint.width, hint.height,
                          1, dpy_depth, InputOutput, visual, mask, &xswa);


  XSelectInput (display, window, StructureNotifyMask);

  /* Tell other applications about this window */

  XSetStandardProperties (display, window, hello, hello, None, NULL, 0, &hint);

  /* Map window. */

  XMapWindow (display, window);

  /* Wait for map. */
  do
  {
    XNextEvent (display, &xev);
  }
  while (xev.type != MapNotify || xev.xmap.event != window);

  XSelectInput (display, window, NoEventMask);

  /* allocate colors */

  gc = DefaultGC (display, screen);

  if (dpy_depth == 8)
  {
    XWindowAttributes xwa;

    cmap = DefaultColormap (display, screen);
    private = 0;

    /* matrix coefficients */
    crv = convmat[matrix_coefficients][0];
    cbu = convmat[matrix_coefficients][1];
    cgu = convmat[matrix_coefficients][2];
    cgv = convmat[matrix_coefficients][3];

    /* color allocation: i is the (internal) 8 bit color number, it
     * consists of separate bit fields for Y, U and V: i = (yyyyuuvv), we
     * don't use yyyy=0000 yyyy=0001 and yyyy=1111, this leaves 48 colors
     * for other applications
     * 
     * the allocated colors correspond to the following Y, U and V values: Y:
     * 40, 56, 72, 88, 104, 120, 136, 152, 168, 184, 200, 216, 232 U,V:
     * -48, -16, 16, 48
     * 
     * U and V values span only about half the color space; this gives
     * usually much better quality, although highly saturated colors can
     * not be displayed properly
     * 
     * translation to R,G,B is implicitly done by the color look-up table */
    for (i = 32; i < 240; i++)
    {
      /* color space conversion */
      y = 16 * ((i >> 4) & 15) + 8;
      u = 32 * ((i >> 2) & 3) - 48;
      v = 32 * (i & 3) - 48;

      y = 76309 * (y - 16);     /* (255/219)*65536 */

      r = clp[(y + crv * v + 32768) >> 16];
      g = clp[(y - cgu * u - cgv * v + 32768) >> 16];
      b = clp[(y + cbu * u + 32786) >> 16];

      /* X11 colors are 16 bit */
      xcolor.red = r << 8;
      xcolor.green = g << 8;
      xcolor.blue = b << 8;

      if (XAllocColor (display, cmap, &xcolor) != 0)
        pixel[i] = xcolor.pixel;
      else
      {
        /* allocation failed, have to use a private colormap */

        if (private)
          error ("Couldn't allocate private colormap");

        private = 1;

        if (!quiet)
          fprintf (stderr, "Using private colormap (%d colors were "
                   "available).\n", i - 32);

        /* Free colors. */
        while (--i >= 32)
        {
          tmp_pixel = pixel[i]; /* because XFreeColors expects unsigned
                                 * long */
          XFreeColors (display, cmap, &tmp_pixel, 1, 0);
        }

        /* i is now 31, this restarts the outer loop */

        /* create private colormap */

        XGetWindowAttributes (display, window, &xwa);
        cmap = XCreateColormap (display, window, xwa.visual, AllocNone);
        XSetWindowColormap (display, window, cmap);
      }
    }
  }
#ifdef SH_MEM
  if (XShmQueryExtension (display))
    shmem_flag = 1;
  else
  {
    shmem_flag = 0;
    if (!quiet)
      fprintf (stderr, "Shared memory not supported\nReverting to normal "
               "Xlib\n");
  }

  if (shmem_flag)
    CompletionType = XShmGetEventBase (display) + ShmCompletion;

  InstallXErrorHandler ();

  if (shmem_flag)
  {

    if (expand)
      ximage = XShmCreateImage (display, visual, dpy_depth, ZPixmap, NULL,
                                &shminfo1,
                      2 * coded_picture_width, 2 * coded_picture_height);
    else
      ximage = XShmCreateImage (display, visual, dpy_depth, ZPixmap, NULL,
                                &shminfo1,
                              coded_picture_width, coded_picture_height);


    /* If no go, then revert to normal Xlib calls. */

    if (ximage == NULL)
    {
      if (ximage != NULL)
        XDestroyImage (ximage);
      if (!quiet)
        fprintf (stderr, "Shared memory error, disabling (Ximage error)\n");
      goto shmemerror;
    }
    /* Success here, continue. */

    shminfo1.shmid = shmget (IPC_PRIVATE,
                             ximage->bytes_per_line * ximage->height,
                             IPC_CREAT | 0777);

    if (shminfo1.shmid < 0)
    {
      XDestroyImage (ximage);
      if (!quiet)
        fprintf (stderr, "Shared memory error, disabling (seg id error)\n");
      goto shmemerror;
    }
    shminfo1.shmaddr = (char *) shmat (shminfo1.shmid, 0, 0);
    shminfo2.shmaddr = (char *) shmat (shminfo2.shmid, 0, 0);

    if (shminfo1.shmaddr == ((char *) -1))
    {
      XDestroyImage (ximage);
      if (shminfo1.shmaddr != ((char *) -1))
        shmdt (shminfo1.shmaddr);
      if (!quiet)
      {
        fprintf (stderr, "Shared memory error, disabling (address error)\n");
      }
      goto shmemerror;
    }
    ximage->data = shminfo1.shmaddr;
    dithered_image = (unsigned char *) ximage->data;
    shminfo1.readOnly = False;
    XShmAttach (display, &shminfo1);

    XSync (display, False);

    if (gXErrorFlag)
    {
      /* Ultimate failure here. */
      XDestroyImage (ximage);
      shmdt (shminfo1.shmaddr);
      if (!quiet)
        fprintf (stderr, "Shared memory error, disabling.\n");
      gXErrorFlag = 0;
      goto shmemerror;
    } else
    {
      shmctl (shminfo1.shmid, IPC_RMID, 0);
    }

    if (!quiet)
    {
      fprintf (stderr, "Sharing memory.\n");
    }
  } else
  {
shmemerror:
    shmem_flag = 0;
#endif


    if (expand)
    {
      ximage = XCreateImage (display, visual, dpy_depth, ZPixmap, 0, &dummy,
                2 * coded_picture_width, 2 * coded_picture_height, 8, 0);
      if (!(dithered_image =
            (unsigned char *) malloc (coded_picture_width * coded_picture_height *
                                      (dpy_depth > 8 ? sizeof (int) * 4 :
                                       sizeof (unsigned char)) * 4)))
        error ("malloc failed");
    } else
    {
      ximage = XCreateImage (display, visual, dpy_depth, ZPixmap, 0, &dummy,
                        coded_picture_width, coded_picture_height, 8, 0);
      if (!(dithered_image =
            (unsigned char *) malloc (coded_picture_width * coded_picture_height *
                                      (dpy_depth > 8 ? sizeof (int) :
                                       sizeof (unsigned char)))))
        error ("malloc failed");
    }

#ifdef SH_MEM
  }

  DeInstallXErrorHandler ();
#endif


  if (dpy_depth == 32 || dpy_depth == 24 || dpy_depth == 16)
  {
    XWindowAttributes xwa;

    XGetWindowAttributes (display, window, &xwa);


    wpixel[0] = xwa.visual->red_mask;
    wpixel[1] = xwa.visual->green_mask;
    wpixel[2] = xwa.visual->blue_mask;

    /* If the colors in 16/24/32-bit mode are wrong, try this instead of
     * the above three lines */
    /* wpixel[2] = xwa.visual->red_mask; wpixel[1] =
     * xwa.visual->green_mask; wpixel[0] = xwa.visual->blue_mask; */

    InitColorDither (dpy_depth == 24 || dpy_depth == 32);
  } else
  {
    ord4x4_dither_init ();
  }
}

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

static void display_image (ximage, dithered_image)
  XImage *ximage;
  unsigned char *dithered_image;
{
  int t = 1;

  /* Always work in native bit and byte order. This tells Xlib to reverse
   * bit and byte order if necessary when crossing a network. Frankly,
   * this part of XImages is somewhat underdocumented, so this may not be
   * exactly correct.  */

  if (*(char *) &t == 1)
  {
    ximage->byte_order = LSBFirst;
    ximage->bitmap_bit_order = LSBFirst;
  } else
  {
    ximage->byte_order = MSBFirst;
    ximage->bitmap_bit_order = MSBFirst;
  }

  /* 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 dither (src)
  unsigned char *src[];
{
  if (dpy_depth == 24 || dpy_depth == 32)
  {
    if (ximage->bits_per_pixel == 24)
      ConvertYUVtoRGB (src[0], src[1], src[2], dithered_image,
                       coded_picture_width,
                       coded_picture_height);
    else
      Color32DitherImage (src, dithered_image);
  } else if (dpy_depth == 16)
  {
    Color16DitherImage (src, dithered_image);
  } else
  {
    ord4x4_dither_frame (src, dithered_image);
  }

  display_image (ximage, dithered_image);
}

#endif