marker.cpp

来自「基于块方向的图像无损压缩代码」· C++ 代码 · 共 225 行

/*++*
* Copyright (c) 1997 University of British Columbia. All rights reserved.
*
*       File:           marker.c
*       Pourpose:       contains the marker Library which used to set the header bytes...
*
*       Author:         Ismaeil R. Ismaeil, Aug. 1997
*
*--*/
#include "stdafx.h"
#include "globals.h"
#include "marker.h"
#include "prototypes.h"

/**********************************************
WriteSoi() puts an SOI marker onto the stream.
**********************************************/

void WriteSoi()
{

  putc(MARKER_MARKER,ofp);
  putc(MARKER_SOI,ofp);
}

/**********************************************
WriteEoi() puts an EOI marker onto the stream.
***********************************************/
void WriteEoi()
{
	putc(MARKER_MARKER,ofp);
	putc(MARKER_EOI,ofp);
}

/***********************************************
WriteSof() puts an SOF marker onto the stream.
***********************************************/
void WriteSof()
{
	putc(MARKER_MARKER,ofp);
	putc(MARKER_SOF,ofp);
	putc(0,ofp);                      /* Put a 0 down onto the stream. */
	putc(0x0b,ofp);
	putc(P,ofp);
	putc(dim.x>>8,ofp); 
	putc(0x00ff&dim.x,ofp);
	putc(dim.y>>8,ofp); 
	putc(0x00ff&dim.y,ofp);
	putc(1,ofp);
	putc(1,ofp);
	putc(0x11,ofp);
	putc(0,ofp);
}


/********************************************
WriteSos() writes a start of scan marker.
*********************************************/
void WriteSos()
{
	putc(MARKER_MARKER,ofp);
	putc(MARKER_SOS,ofp);
	putc(0,ofp);
	putc(8,ofp);
	putc(1,ofp);
	putc(1,ofp);
	putc(0,ofp);
	putc(0,ofp);
	putc(0,ofp);
	putc(0,ofp);
}


/*************************************************
  ReadSoi reads a start of image from the stream.
**************************************************/
void ReadSoi()
{
	if (getc(ifp) != MARKER_MARKER)
	{
		fprintf(stderr,"Can not recognize the header Marker SOI\n");
		exit(0);
	}

	if (getc(ifp) != MARKER_SOI)
	{
		fprintf(stderr,"Can not recognize the header SOI\n");
		exit(0);
	}
}

/**************************************************************************
  ReadSof() reads a start of frame marker from the stream. We assume that
  the first two bytes (marker prefix) have already been stripped.
**************************************************************************/  
void ReadSof()
{

	if (getc(ifp) != MARKER_MARKER)
	{
		fprintf(stderr,"Can not recognize the header SOF\n");
		exit(0);
	}
	if (getc(ifp) != MARKER_SOF)
	{
		fprintf(stderr,"Can not recognize the header SOF\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}

	if (getc(ifp) != 0x0b)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}
 
	P = getc(ifp);
	if (P <= 0 || P > 16)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}

	dim.x  = getc(ifp) << 8;
	dim.x += getc(ifp);
	dim.y  = getc(ifp) << 8;
	dim.y += getc(ifp);

	if (getc(ifp) != 1)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}

	if (getc(ifp) != 1)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}

	if (getc(ifp) != 0x11)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOF\n");
		exit(0);
	}
}

/*****************************************************************
ReadSos() reads in a start of scan from the stream. The first two
bytes should have been stripped off.
*****************************************************************/
void ReadSos()
{
	if (getc(ifp) != MARKER_MARKER)
	{
		fprintf(stderr,"Can not recognize the header SOS\n");
		exit(0);
	}
	
	if (getc(ifp) != MARKER_SOS)
	{
		fprintf(stderr,"Can not recognize the header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 8)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}
	
	if (getc(ifp) != 1)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 1)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}
	
	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}

	if (getc(ifp) != 0)
	{
		fprintf(stderr,"Error reading header SOS\n");
		exit(0);
	}
}