Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!sun!swap!page
From: page%swap@Sun.COM (Bob Page)
Newsgroups: comp.sources.amiga
Subject: v89i120:  iff2sixel - convert iff files to dec sixel format
Message-ID: <103774@sun.Eng.Sun.COM>
Date: 9 May 89 05:00:30 GMT
Sender: news@sun.Eng.Sun.COM
Lines: 778
Approved: page@sun.com

Submitted-by: kennedy%wwpacs@dupont.com (Tony Kennedy)
Posting-number: Volume 89, Issue 120
Archive-name: iff/iff2sixel.1

Here's a program I wrote to convert IFF pictures to DEC Sixels.  You
can now display IFF files on VT240s, VT241s, VT340s and the like.

[binary not available; use your favorite compiler.  ..bob]

# This is a shell archive.
# Remove anything above and including the cut line.
# Then run the rest of the file through 'sh'.
# Unpacked files will be owned by you and have default permissions.
#----cut here-----cut here-----cut here-----cut here----#
#!/bin/sh
# shar: SHell ARchive
# Run the following text through 'sh' to create:
#	ReadMe
#	iff2sixel.c
# This is archive 1 of a 1-part kit.
# This archive created: Mon May  8 21:54:31 1989
echo "extracting ReadMe"
sed 's/^X//' << \SHAR_EOF > ReadMe
XHi there,
X
XHere's the program. It's got a few limitations. It NEEDS a 16 color
Xfile for a 340 (you can use fewer that 16 but not more), or 4 colors
Xfor a 240.  I ran it with HAM converted to hires interlace with
XPixmate and they look great.  The best results are the 16 color hires
Xinterlaced picts.
X
XLet me know if you find this program useful and if there are any bugs.
XAlso please let me know what environment/compiler/linker you used (for
Xfuture versions)
X
X			Enjoy...
X				...Tony
SHAR_EOF
echo "extracting iff2sixel.c"
sed 's/^X//' << \SHAR_EOF > iff2sixel.c
X/*****************************************************************************/
X/*									     
X	Program  : IFF2SIXEL.C
X
X	Author   : Tony Kennedy
X		   Internet address: kennedam%wwps@dupont.com@relay.cs.net
X
X	Purpose  : This program takes a AMIGA IFF ILBM file and converts
X		   it to a SIXEL file to be displayed on DIGITAL EQUIPMENT
X		   CORP. VT240, VT241, VT340 terminals. 
X                                 
X		   This version will handle only 16 colors for a VT340 and
X		   4 colors for a VT240. It does no color compression, so
X		   all input files must be 16 colors or less for a 340,
X		   4 colors or less for a 240. 
X
X		   If the display is a VT240/241 then the resolution
X		   is set to 640X200. If it's a 340 then the res is 640X400.
X
X		   I tried to make it a generic as possible so you can 
X		   compile it under what ever environment you please.
X		   If you do it under VMS you will need to define IFF2SIXEL
X		   as a foreign command i.e.  $ iff2sixel :== $mydir:iff2sixel
X		   otherwise you can't use command line args.
X
X	Usage    : iff2sixel <input_file> <output_file> <VT240 | VT340>
X
X	Comments : This program is Freely Distributable. You may
X		   use it for any non-commercial uses.  
X                   (If anybody hacks at this please send me a copy.)
X
X	Acknowledgements : Thanks to...
X
X			 	Carter Brock for the SHOW_IFF program I used
X				to figure out how to read an IFF file.
X
X				Mark Thompson and Steve Berry for the IFF2SUN
X				program I used to figure out how to interpret
X				the bitplanes.
X
X				Barry Young for his help with SIXEL formats.
X
X				Daniel Jay Barrett for his switching bytes
X				hacks.
X
X	Limitations : This won't do HAM or Halfbrite. When I figure them out
X		      I'll put that in too.
X		      Won't do any color compression.
X
X
X	Versions:		Revisions : 
X	
X	1.0  3/1/89 		Original program.
X
X*/
X/*****************************************************************************/
X
X#include <stdio.h>
X#include <math.h>
X
X#define Sixel_base 63
X#define DCS        144
X#define ST         156
X#define QUOTE      34
X
X#define LoRes  1
X#define LoLace 2
X#define HiRes  3
X#define HiLace 4
X
X#define VT240_LoRes  1
X#define VT240_LoLace 2
X#define VT240_HiRes  3
X#define VT240_HiLace 4
X#define VT340_LoRes  5
X#define VT340_LoLace 6
X#define VT340_HiRes  7
X#define VT340_HiLace 8
X
X typedef unsigned char ID_type[4];
X struct ChunkType
X	{
X		ID_type Ident ;
X		long    ChunkSize ;
X	} ;
X struct ChunkType chunk ;
X
X typedef struct 
X	{
X		unsigned char red, green, blue;
X	} ColorRegType;                   
X
X unsigned char BitPlaneArray[400][6][128]; /* vert posit, plane, width posit*/  
X unsigned char PixelArray[400][640];      /* vert posit, horiz posit */
X int	       SixelLine[16][640][80];   /* color,horizontal posit, row.*/
X int	       vert, horz, s_vert, v_bit;
X
X/********************************************************************
X
X	This function decompresses the IFF file. I got the algorithm
X	from Mark and Steve who got it from Leo (The Great Caped One).
X
X********************************************************************/
X
X int decompress_planes(nplanes,width,height,inp_file)
X
X unsigned short nplanes,width,height;
X FILE *inp_file;
X 
X {
X   long h,p,count,BytesPerRow;
X   char len;
X   unsigned char byte;
X
X   for (h=0;h<height;h++)
X     {
X	for (p=0;p<nplanes;p++)
X	  {
X	     count = 0;
X	     BytesPerRow=width/8;
X	     while(BytesPerRow>0)
X		{
X		  if ((len = getc(inp_file)) >= 0)
X		     {
X			BytesPerRow -= ++len;
X			fread(&BitPlaneArray[h][p][count],len,1,inp_file);
X			count += len;
X		     }
X		  else 
X		     if (len < 0)
X		     {
X			len = -len + 1;
X			BytesPerRow -= len;
X			byte = getc(inp_file);
X			while (--len >= 0)
X				BitPlaneArray[h][p][count++] = byte;
X		     }
X		}
X	     if (BytesPerRow) printf("Compression is corrupt.\n");
X	}
X     }
X  }
X
X/********************************************************************
X
X	Since the VAX reads shorts and longs backwards we've got to 
X	flip them around...
X
X********************************************************************/
X
X#ifdef VAX
X
Xshort flip_byte_short(s)
X
X  short s;
X  {
X	short hib,lob;
X
X	lob = (s & 255);
X	hib = ((s >> 8) & 255);
X	return ((lob << 8) + hib);
X  }
X
Xlong flip_bytes_long(l)
X
X  long l;
X  {
X	short low,hiw;
X
X	low = (l & 65535);
X	hiw = ((l >> 16) & 65535);
X	return ( ((flip_byte_short(low) << 16) + flip_byte_short(hiw)));
X  }
X#endif
X
X/********************************************************************
X
X	Convert a string to upper case.
X
X********************************************************************/
X
Xchar *upcase(str)
X 
X  char *str;
X
X  {
X	int len, i;
X
X	i=0;
X	len=strlen(str);
X	while(i != len)
X		{
X		  str[i]=toupper(str[i]);
X		  i++;
X		}
X	return str;
X  }
X
X/********************************************************************
X
X	Double the width of the Pixel Array.
X
X********************************************************************/
X
X short double_width(width,height)
X
X  short width,height;
X
X  {
X	short h,w;
X	for (h=0;h<height;h++)
X	  {
X	    for (w=width-1;w>=0;w--)
X		{
X		  PixelArray[h][w * 2] = PixelArray[h][w];
X		  PixelArray[h][(w * 2)+1] = PixelArray[h][w];
X		}                       
X	  }
X	  return (width * 2);
X  }
X
X/********************************************************************
X
X	Double the height of the Pixel array.
X
X********************************************************************/
X
X short double_height(width,height)
X
X  short width,height;
X
X  {
X	short h,w;
X	for (w=0;w<width;w++)
X	  for (h=height-1;h>=0;h--)
X		{
X		  PixelArray[h * 2][w]=PixelArray[h][w];
X		  PixelArray[(h * 2)+1][w]=PixelArray[h][w];
X		}
X	return (height * 2);
X  }
X
X/********************************************************************
X
X	Halve the height of the Pixel Array. This is gonna make the
X	picture look pretty ugly if you ask me. Only gets done if a
X	picture for a VT240 from an interlace IFF file is being 
X	generated.
X
X********************************************************************/
X
Xshort halve_height(width,height)
X
X  short width,height;
X
X  {
X	short h,w;
X	for (h=0;h<height;h++)
X		for (w=0;w<=width;w++)
X			PixelArray[h][w]=PixelArray[(h * 2)][w];
X
X	return (height/2);
X  }                                            
Xmain (argc,argv)
X
X int argc;
X char **argv[];
X 
X {
X  long num_colors;
X  int stat;
X  long posit,h,w,p,i,j,k,l,m,pixel;
X  long w_pos,cnt_100,cnt_10,cnt_1,rep_cnt;
X  char ch, outline[700];
X  unsigned char  color;
X  char *term;
X  char term_type[5];
X  char *input_file;
X  char *output_file;
X  FILE *outf,*inf;
X  char start_sixel = DCS;
X  char end_sixel = ST;
X  char quote = QUOTE;
X  int  convert_mode = 0;
X  int  resolution;
X
X  struct BitMapHeaderType
X	{
X		unsigned short width, height;
X		short          org_x, org_y;
X		unsigned char  NumPlanes, Mask, Compression, pad;
X		unsigned short TransColor;
X		unsigned char  X_Asp, Y_Asp;
X		unsigned short PageWid, PageHeight;
X	} ;
X  struct BitMapHeaderType bmhd;
X                              
X  ColorRegType CMap[16];
X  
X/*********************************************************************
X
X First, get all the needed info from the user...			
X  			
X	Input file, Output file, Type of terminal to create a file for.
X
X*********************************************************************/
X  switch (argc)
X    {
X	case 1 :
X		printf("Input File Name : ");
X		scanf ("%s",&input_file);
X		printf("Output File Name : ");
X		scanf("%s",&output_file);	
X		printf("\nThis will generate SIXELS for a VT240 @ 640x240.\n");
X		printf("or a VT340 @ 640x480.\n");	
X		printf("Enter VT240 or VT340 : ");
X		scanf("%s",&term_type);
X		inf = fopen(&input_file,"r");
X		outf = fopen(&output_file,"w");
X		term = &term_type;
X		break;                   
X		
X	case 2 :
X		
X		printf("Output File Name : ");
X		scanf("%s",&output_file);	
X		printf("\nThis will generate SIXELS for a VT240 @ 640x240.\n");
X		printf("or a VT340 @ 640x480.\n");	
X		printf("Enter VT240 or VT340 : ");
X		scanf("%s",&term_type);
X		inf = fopen(argv[1],"r");
X		outf = fopen(&output_file,"w");
X		term = &term_type;
X		break;             
X
X	case 3 :
X		                         	
X		printf("\nThis will generate SIXELS for a VT240 @ 640x240.\n");
X		printf("or a VT340 @ 640x480.\n");	
X		printf("Enter VT240 or VT340 : ");
X		scanf("%s",&term_type);
X		inf = fopen(argv[1],"r");
X		outf = fopen(argv[2],"w");
X		term = &term_type;
X		break;              
X
X	case 4 :
X		
X		inf = fopen(argv[1],"r");
X		outf = fopen(argv[2],"w");
X		term = argv[3];
X		           
X    }
X
X    if (outf == NULL) {
X      printf("Output can't be opened.\n");
X      exit(0); }
X	
X    if (inf == NULL) {
X      printf("Input file can't be opened.\n");
X      exit(0); }
X
X
X/*********************************************************************
X
X	Ok. Now read in the IFF file...
X
X*********************************************************************/
X
X	
X	stat=fread(chunk.Ident,4,1,inf);
X	if (stat == -1) 
X		{
X			printf("Error reading file.\n");
X			stat=close(inf) ; stat=close(outf);
X			exit(0);
X                }
X	                                 
X
X	while (strncmp(chunk.Ident,"FORM",4) !=0)  
X		stat=fread(chunk.Ident,4,1,inf);
X                                 
X	if (strncmp(chunk.Ident,"FORM",4) != 0)
X		{
X			printf("Error, not a FORM file.\n");
X			stat=close(inf); stat=close(outf);
X			exit(0);
X		}
X
X	stat=fread(&chunk.ChunkSize,4,1,inf);
X
X	stat=fread(chunk.Ident,4,1,inf);
X                                               
X	while (strncmp(chunk.Ident,"ILBM",4) !=0)  
X		stat=fread(chunk.Ident,4,1,inf);
X                                 
X	if (strncmp(chunk.Ident, "ILBM",4) !=0)
X                                               
X		{
X			printf("Error Not an ILBM file.\n");
X	      		stat=close(inf); stat=close(outf);
X			exit(0);
X		}                              
X	stat=fread(chunk.Ident,4,1,inf);
X        
X	while (strncmp(chunk.Ident,"BMHD",4) !=0)  
X		stat=fread(chunk.Ident,4,1,inf);
X                                 
X	if (strncmp(chunk.Ident, "BMHD",4) !=0)
X		{
X			printf("Error can't find Bit Map Header.\n");
X	      		stat=close(inf); stat=close(outf);
X			exit(0);
X		}                              
X
X	stat=fread(&chunk.ChunkSize,4,1,inf);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.width = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.height = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.org_x = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.org_y = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	bmhd.NumPlanes = *((char *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	bmhd.Mask = *((char *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	bmhd.Compression = *((char *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.TransColor = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	bmhd.X_Asp = *((char *)chunk.Ident);
X	stat=fread(chunk.Ident,1,1,inf);
X	bmhd.Y_Asp = *((char *)chunk.Ident);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.PageWid = *((short *)chunk.Ident);
X	stat=fread(chunk.Ident,2,1,inf);
X	bmhd.PageHeight = *((short *)chunk.Ident);
X
X	if (stat == -1)
X		{
X			printf("Error failed to get Bit Map information.\n");
X	      		stat=close(inf); stat=close(outf);
X			exit(0);
X		}
X
X
X	stat=fread(chunk.Ident,4,1,inf);
X        
X	while (strncmp(chunk.Ident,"CMAP",4) !=0)  
X		stat=fread(chunk.Ident,4,1,inf);
X                                 
X	if (strncmp(chunk.Ident,"CMAP",4) !=0)
X		{
X			printf("Error can't find Color Map.\n");
X	      		stat=close(inf); stat=close(outf);
X			exit(0);
X		}                 
X        stat=fread(&num_colors,4,1,inf);           
X
X#ifdef VAX
X
X	bmhd.width=flip_byte_short(bmhd.width);
X	bmhd.height=flip_byte_short(bmhd.height);
X	bmhd.org_x=flip_byte_short(bmhd.org_x);
X	bmhd.org_y=flip_byte_short(bmhd.org_y);
X	bmhd.TransColor=flip_byte_short(bmhd.TransColor);
X	bmhd.PageWid=flip_byte_short(bmhd.PageWid);
X	bmhd.PageHeight=flip_byte_short(bmhd.PageHeight);
X	num_colors=flip_bytes_long(num_colors);
X
X#endif
X
X/********************************************************************
X
X	define conversion mode
X
X********************************************************************/
X
X	if ((bmhd.width==320)&&(bmhd.height==200)) resolution = LoRes;
X	if ((bmhd.width==320)&&(bmhd.height==400)) resolution = LoLace;
X	if ((bmhd.width==640)&&(bmhd.height==200)) resolution = HiRes;
X	if ((bmhd.width==640)&&(bmhd.height==400)) resolution = HiLace;
X
X                                                             
X	if  ((strcmp(upcase(term),"VT240",5) == 0) &&  
X	     (resolution==LoRes)) convert_mode=VT240_LoRes;
X
X	if  ((strcmp(upcase(term),"VT240",5) == 0) &&  
X	     (resolution==LoLace)) convert_mode=VT240_LoLace;
X
X	if  ((strcmp(upcase(term),"VT240",5) == 0) &&  
X	     (resolution==HiRes)) convert_mode=VT240_HiRes;
X
X	if  ((strcmp(upcase(term),"VT240",5) == 0) &&  
X	     (resolution==HiLace)) convert_mode=VT240_HiLace;
X
X	if  ((strcmp(upcase(term),"VT340",5) == 0) &&  
X	     (resolution==LoRes)) convert_mode=VT340_LoRes;
X
X	if  ((strcmp(upcase(term),"VT340",5) == 0) &&  
X	     (resolution==LoLace)) convert_mode=VT340_LoLace;
X
X	if  ((strcmp(upcase(term),"VT340",5) == 0) &&  
X	     (resolution==HiRes)) convert_mode=VT340_HiRes;
X
X	if  ((strcmp(upcase(term),"VT340",5) == 0) &&  
X	     (resolution==HiLace)) convert_mode=VT340_HiLace;
X
X	if (!convert_mode) {
X		printf("IFF picture is an irregular size.\n");
X		close(inf);
X		close(outf);
X		exit(0);
X			   }
X
X
X	num_colors=num_colors/3;                         
X	stat=fread(CMap,(num_colors * 3),1,inf);
X                
X        if ( (num_colors > 16) ||
X	     ((num_colors > 4) && (strcmp(upcase(term),"VT240",5) == 0))
X	   )
X
X		{
X		   printf("File has too many colors for this conversion.\n");
X		   close(inf);
X		   close(outf);
X		   exit(0);
X		}
X
X/********************************************************************
X
X	Skip everything till we find the BODY.
X
X********************************************************************/
X                                         
X	stat=fread(chunk.Ident,4,1,inf); 
X	while (strncmp(chunk.Ident,"BODY",4) !=0)  
X		stat=fread(chunk.Ident,4,1,inf);
X                                 
X
X	stat=fread(chunk.Ident,4,1,inf); /* body length */
X
X
X/********************************************************************
X
X	Now read the bit planes in.
X
X********************************************************************/
X
X	if (bmhd.Compression == 1)
X		decompress_planes(bmhd.NumPlanes,bmhd.width,bmhd.height,inf);
X	else
X
X		for (h = 0;h<bmhd.height;h++)
X			for (p = 0;p<bmhd.NumPlanes;p++) 
X				{
X				 for (w = 0;w<bmhd.width/8;w++) 
X					{
X					 if (feof(inf)) continue;
X					 read(inf,BitPlaneArray[h][p][w],1);
X			                }
X                                }
X	close(inf);
X
X/********************************************************************
X
X	Translate bit planes to pixel color values.
X
X********************************************************************/
X
X    	for (h = 0;h<bmhd.height;h++)
X	 {
X	 w_pos = 0;
X	 for (w=0;w<bmhd.width/8;w++)
X	   {                                                   
X	    pixel = 0;    
X	    for (i=7;i>=0;i--)
X	      {
X	       
X		for (p=0;p<bmhd.NumPlanes;p++)
X		  pixel = ((((1 << i) & BitPlaneArray[h][p][w])>>i)<<p)|pixel;
X	       
X		PixelArray[h][w_pos++] = (char)(pixel & 0x1f); 
X		pixel = 0;
X	      }                                              
X	   }
X	 }	
X
X/********************************************************************
X
X	Convert to screen size.
X
X********************************************************************/
X
X	switch(convert_mode)
X
X		{
X		     case VT240_LoRes : 
X			  bmhd.width = double_width(bmhd.width,bmhd.height);
X                          break;                        
X
X	             case VT240_LoLace :
X			  bmhd.height = halve_height(bmhd.width,bmhd.height);
X			  bmhd.width = double_width(bmhd.width,bmhd.height);
X			  break;
X		     
X		     case VT240_HiRes : 
X			  break;
X	                  
X		     case VT240_HiLace :
X			  bmhd.height = halve_height(bmhd.width,bmhd.height);
X			  break;
X
X		     case VT340_LoRes :
X			  bmhd.width = double_width(bmhd.width,bmhd.height);
X			  bmhd.height = double_height(bmhd.width,bmhd.height);
X			  break;
X
X		     case VT340_LoLace :
X			  bmhd.width = double_width(bmhd.width,bmhd.height);
X                          break;                        
X
X		     case VT340_HiRes :
X			  bmhd.height = double_height(bmhd.width,bmhd.height);
X			  break;
X
X		     case VT340_HiLace :
X			  break;
X
X		}
X                
X/********************************************************************
X
X	Convert Pixels to Sixels.
X
X********************************************************************/
X
X	vert=bmhd.height;
X	horz=bmhd.width;
X	v_bit = 0;
X                                
X	for (i=0;i<vert;i++)
X	   {
X		s_vert = i/6;
X		v_bit= i%6;
X		for (j=0;j<horz;j++)
X		   {
X		    color = PixelArray[i][j];                               
X		    SixelLine[color][j][s_vert] |= (int)pow(2,v_bit);
X		   }      
X	   }
X                		
X                                                   
X/********************************************************************
X
X	Compress Sixels and write to file.
X
X********************************************************************/
X
X	
X	vert = bmhd.height/6;
X
X/*	Write Sixel start code. */
X
X	fprintf(outf,"%c;1;;q%c1;1;;\n",start_sixel,quote);
X
X/*	Write color map. */
X
X	for (color=0;color<num_colors;color++)
X	  {
X		CMap[color].red   = (CMap[color].red * 100)/255;		
X		CMap[color].green = (CMap[color].green * 100)/255;
X		CMap[color].blue  = (CMap[color].blue * 100)/255;
X		fprintf(outf,"#%d;2;%d;%d;%d\n",color,
X		        CMap[color].red,CMap[color].green,CMap[color].blue);
X
X	  }
X	  fprintf(outf,"\n");
X
X
X/* 	Compress and write Sixels. */
X
X	for (s_vert=0;s_vert <= vert;s_vert++)
X	 {
X	   for (color=0;color<num_colors;color++)
X	    {
X
X	      for (j=0;j<horz;j++)                                
X			SixelLine[color][j][s_vert] += Sixel_base;
X	      i = 0;
X	      k = 0;
X	      while( i < horz )
X		{
X		   ch = SixelLine[color][i][s_vert];			
X		   l=i;
X
X		   while ((l < horz) && (ch == SixelLine[color][l][s_vert]))
X			l++;
X		   rep_cnt = l - i;
X		   if (rep_cnt >= 5)
X			{
X			   cnt_100 = rep_cnt/100;
X			   cnt_10  = (rep_cnt-(cnt_100 * 100))/10;
X			   cnt_1   = (rep_cnt-((cnt_100 * 100)+(cnt_10 * 10)));
X			   outline[k] = 33; /* Exclamation mark */
X			   outline[k+1] = cnt_100 + 48;
X			   outline[k+2] = cnt_10  + 48;
X			   outline[k+3] = cnt_1   + 48;
X			   outline[k+4] = SixelLine[color][l-1][s_vert];
X			   k += 5;
X			   i=l;
X			}
X		   else
X			{
X			   for (m=0;m<=(l-1)-i;m++)
X				   outline[k+m]=SixelLine[color][l-1][s_vert];
X			   k += (l-i);
X			   i=l;
X			}
X		}         
X		outline[k]=0;
X		fprintf(outf,"#%d %s$\n",color,&outline); 
X
X	    }
X	    fprintf(outf," - \n");
X	}
X	fprintf(outf,"%c\n",ST);
X	close(outf);
X     }
SHAR_EOF
echo "End of archive 1 (of 1)"
# if you want to concatenate archives, remove anything after this line
exit