/* ** GIFtrans v1.9 ** ** Convert any GIF file into a GIF89a ** Allows for setting a transparent color and adding a comment ** Also code to analyze GIF contents ** ** Copyright (c) 24.2.94 by Andreas Ley ** ** Permission to use, copy, modify, and distribute this software for any ** purpose and without fee is hereby granted, provided that the above ** copyright notice appears in all copies. This software is provided "as is" ** and without any express or implied warranties. ** ** This program has been tested on a HP9000/720 with HP-UX A.08.07 ** In this environment, neither lint -u nor gcc -Wall produce any messages. ** If you encounter any errors or need to make any changes to port it ** to another platform, please contact me. ** ** Version history ** ** Version 1.9 - 1.6.94 ** Fixed a bug which caused color names to be rejected. ** ** Version 1.8 - 30.5.94 ** Accept #rrggbb style arguments. ** Do nothing if rgb-color not found in GIF. ** ** Version 1.7 - 16.5.94 ** Added -l option to only list the color table. ** Added -L option for verbose output without creating a gif. ** Added -b option to change the background color index. ** Display all matching color names for color table entries. ** Fixed a bug which caused bad color names if rgb.txt starts with ** whitespace. ** Doesn't use strdup anymore. ** Fixed =& bug on dec machines. ** ** Version 1.6 - 5.4.94 ** Added color names recognition. ** ** Version 1.5 - 15.3.94 ** Added basic verbose output to analyze GIFs. ** ** Version 1.4 - 8.3.94 ** Fixed off-by-one bug in Local Color table code. ** Added option to add or remove a comment. ** Transparency is no longer the default. ** ** Thanx for bug reports, ideas and fixes to ** patricka@cs.kun.nl (Patrick Atoon) ** wes@msc.edu (Wes Barris) ** pmfitzge@ingr.com (Patrick M. Fitzgerald) ** hoesel@chem.rug.nl (frans van hoesel) ** boardman@jerry.sal.wisc.edu (Dan Boardman) ** krweiss@chip.ucdavis.edu (Ken Weiss) ** chuck@trantor.harris-atd.com (Chuck Musciano) ** heycke@camis.stanford.edu (Torsten Heycke) ** claw@spacsun.rice.edu (Colin Law) ** jwalker@eos.ncsu.edu (Joseph C. Walker) ** Bjorn.Borud@alkymi.unit.no (Bjorn Borud) ** Christopher.Vance@adfa.oz.au (CJS Vance) ** pederl@norway.hp.com (Peder Langlo) ** ** Original distribution site is ** ftp://ftp.rz.uni-karlsruhe.de/pub/net/www/tools/giftrans.c ** Additional info can be found on ** http://melmac.harris-atd.com/transparent_images.html */ char header[]="GIFtrans v1.9\n(c) 1994 by Andreas Ley\n"; char rgb[]="/usr/lib/X11/rgb.txt"; #include #include #include #include #include #include #define FALSE (0) /* This is the naked Truth */ #define TRUE (1) /* and this is the Light */ #define SUCCESS (0) #define FAILURE (1) struct entry { struct entry *next; char *name; int red; int green; int blue; } *root; #define NONE (-1) #define OTHER (-2) #define RGB (-3) struct color { int index; int red; int green; int blue; } bc,tc; char *image,*comment; int skipcomment; int list,verbose,output=TRUE; char true[]="True"; char false[]="False"; #define readword(buffer) ((buffer)[0]+256*(buffer)[1]) #define readflag(buffer) ((buffer)?true:false) #define hex(c) ('a'<=(c)&&(c)<='z'?(c)-'a'+10:'A'<=(c)&&(c)<='Z'?(c)-'A'+10:(c)-'0') void writedata(dest,data,len) FILE *dest; char *data; size_t len; { unsigned char size; while (len) { size=len<256?len:255; (void)fwrite((void *)&size,1,1,dest); (void)fwrite((void *)data,(size_t)size,1,dest); data+=size; len-=size; } size=0; (void)fwrite((void *)&size,1,1,dest); } void skipdata(src) FILE *src; { unsigned char size; do { (void)fread((void *)&size,1,1,src); (void)fseek(src,(long int)size,SEEK_CUR); } while (!feof(src)&&size>0); } void transblock(src,dest) FILE *src; FILE *dest; { unsigned char size,buffer[256]; (void)fread((void *)&size,1,1,src); if (output) (void)fwrite((void *)&size,1,1,dest); (void)fread((void *)buffer,(size_t)size,1,src); if (output) (void)fwrite((void *)buffer,(size_t)size,1,dest); } void transdata(src,dest) FILE *src; FILE *dest; { unsigned char size,buffer[256]; do { (void)fread((void *)&size,1,1,src); if (output) (void)fwrite((void *)&size,1,1,dest); (void)fread((void *)buffer,(size_t)size,1,src); if (output) (void)fwrite((void *)buffer,(size_t)size,1,dest); } while (!feof(src)&&size>0); } int giftrans(src,dest) FILE *src; FILE *dest; { unsigned char buffer[3*256],lsd[7],gce[5]; unsigned int cnt,cols,size,gce_present; struct entry *rgbptr; /* Header */ (void)fread((void *)buffer,6,1,src); if(strncmp((char *)buffer,"GIF",3)) { (void)fprintf(stderr,"No GIF file!\n"); return(1); } if (verbose) { buffer[6]='\0'; (void)fprintf(stderr,"Header: \"%s\"\n",buffer); } if (output) (void)fputs("GIF89a",dest); /* Logical Screen Descriptor */ (void)fread((void *)lsd,7,1,src); if (verbose) { (void)fprintf(stderr,"Logical Screen Descriptor:\n"); (void)fprintf(stderr,"\tLogical Screen Width: %d pixels\n",readword(lsd)); (void)fprintf(stderr,"\tLogical Screen Height: %d pixels\n",readword(lsd+2)); (void)fprintf(stderr,"\tGlobal Color Table Flag: %s\n",readflag(lsd[4]&0x80)); (void)fprintf(stderr,"\tColor Resolution: %d bits\n",(lsd[4]&0x70>>4)+1); if (lsd[4]&0x80) { (void)fprintf(stderr,"\tSort Flag: %s\n",readflag(lsd[4]&0x8)); (void)fprintf(stderr,"\tSize of Global Color Table: %d colors\n",2<<(lsd[4]&0x7)); (void)fprintf(stderr,"\tBackground Color Index: %d\n",lsd[5]); } if (lsd[6]) (void)fprintf(stderr,"\tPixel Aspect Ratio: %d (Aspect Ratio %f)\n",lsd[6],((double)lsd[6]+15)/64); } /* Global Color Table */ if(lsd[4]&0x80) { size=2<<(lsd[4]&0x7); (void)fread((void *)buffer,size,3,src); if (bc.index==RGB) for(cnt=0;cnt=0) lsd[5]=bc.index; if (tc.index==RGB) for(cnt=0;cntnext) if (rgbptr->red==buffer[3*cnt]&&rgbptr->green==buffer[3*cnt+1]&&rgbptr->blue==buffer[3*cnt+2]) (void)fprintf(stderr,"%s%s",cols++?", ":" (",rgbptr->name); (void)fprintf(stderr,"%s\n",cols?")":""); } } if (output) (void)fwrite((void *)buffer,size,3,dest); } gce_present=FALSE; do { (void)fread((void *)buffer,1,1,src); switch (buffer[0]) { case 0x01: /* Plain Text Extension */ if (verbose) (void)fprintf(stderr,"Plain Text Extension: 0x%02x\n",buffer[0]); if (output) (void)fwrite((void *)buffer,1,1,dest); transblock(src,dest); transdata(src,dest); break; case 0x2c: /* Image Descriptor */ if (verbose) (void)fprintf(stderr,"Image Descriptor: 0x%02x\n",buffer[0]); /* Write Graphic Control Extension */ if (tc.index>=0||gce_present) { if (output) (void)fputs("\041\371\004",dest); if (!gce_present) { gce[0]=0; gce[1]=0; gce[2]=0; } if (tc.index>=0) { gce[0]|=0x01; /* Set Transparent Color Flag */ gce[3]=tc.index; /* Set Transparent Color Index */ } gce[4]=0; if (output) (void)fwrite((void *)gce,5,1,dest); } /* Write Image Descriptor */ (void)fread((void *)(buffer+1),9,1,src); if (verbose) { (void)fprintf(stderr,"\tImage Left Position: %d pixels\n",readword(buffer+1)); (void)fprintf(stderr,"\tImage Top Position: %d pixels\n",readword(buffer+3)); (void)fprintf(stderr,"\tImage Width: %d pixels\n",readword(buffer+5)); (void)fprintf(stderr,"\tImage Height: %d pixels\n",readword(buffer+7)); (void)fprintf(stderr,"\tLocal Color Table Flag: %s\n",readflag(buffer[9]&0x80)); (void)fprintf(stderr,"\tInterlace Flag: %s\n",readflag(buffer[9]&0x40)); if (buffer[9]&0x80) { (void)fprintf(stderr,"\tSort Flag: %s\n",readflag(buffer[9]&0x20)); (void)fprintf(stderr,"\tSize of Global Color Table: %d colors\n",2<<(buffer[9]&0x7)); } } if (output) (void)fwrite((void *)buffer,10,1,dest); /* Local Color Table */ if(buffer[8]&0x80) { size=2<<(buffer[8]&0x7); (void)fread((void *)buffer,size,3,src); if (verbose) { (void)fprintf(stderr,"Local Color Table:\n"); for(cnt=0;cnt>2); switch (gce[0]&0x1c>>2) { case 0: (void)fprintf(stderr,"(no disposal specified)\n"); break; case 1: (void)fprintf(stderr,"(do not dispose)\n"); break; case 2: (void)fprintf(stderr,"(restore to background color)\n"); break; case 3: (void)fprintf(stderr,"(restore to previous)\n"); break; default: (void)fprintf(stderr,"(to be defined)\n"); } (void)fprintf(stderr,"\tUser Input Flag: %s\n",readflag(gce[0]&0x2)); (void)fprintf(stderr,"\tTransparent Color Flag: %s\n",readflag(gce[0]&0x1)); (void)fprintf(stderr,"\tDelay Time: %d\n",readword(gce+1)); if (gce[0]&0x1) (void)fprintf(stderr,"\tTransparent Color Index: %d\n",gce[3]); } (void)fread((void *)buffer,1,1,src); gce_present=TRUE; break; case 0xfe: /* Comment Extension */ if (verbose) (void)fprintf(stderr,"Comment Extension: 0x%02x 0x%02x\n",buffer[0],buffer[1]); if (skipcomment) skipdata(src); else { if (output) (void)fwrite((void *)buffer,2,1,dest); transdata(src,dest); } break; case 0xff: /* Application Extension */ if (verbose) (void)fprintf(stderr,"Application Extension: 0x%02x 0x%02x\n",buffer[0],buffer[1]); if (output) (void)fwrite((void *)buffer,2,1,dest); transblock(src,dest); transdata(src,dest); break; default: (void)fprintf(stderr,"0x%08lx: Unknown label 0x%02x!\n",ftell(src)-1,buffer[1]); return(1); } break; default: (void)fprintf(stderr,"0x%08lx: Unknown extension 0x%02x!\n",ftell(src)-1,buffer[0]); return(1); } } while (buffer[0]!=0x3b&&!feof(src)); return(buffer[0]==0x3b?SUCCESS:FAILURE); } int getindex(c,arg) struct color *c; char *arg; { struct entry *ptr; if ('0'<=*arg&&*arg<='9') c->index=atoi(arg); else if (*arg=='#') { if (strlen(arg)==4) { c->index=RGB; c->red=hex(arg[1])<<4; c->green=hex(arg[2])<<4; c->blue=hex(arg[3])<<4; } else if (strlen(arg)==7) { c->index=RGB; c->red=(hex(arg[1])<<4)+hex(arg[2]); c->green=(hex(arg[3])<<4)+hex(arg[4]); c->blue=(hex(arg[5])<<4)+hex(arg[6]); } else { (void)fprintf(stderr,"%s: illegal color specification: %s\n",image,arg); return(FAILURE); } } else { for (ptr=root;ptr&&c->index!=RGB;ptr=ptr->next) if (!strcmp(ptr->name,arg)) { c->index=RGB; c->red=ptr->red; c->green=ptr->green; c->blue=ptr->blue; } if (c->index!=RGB) { (void)fprintf(stderr,"%s: no such color: %s\n",image,arg); return(FAILURE); } } return(SUCCESS); } void usage() { (void)fprintf(stderr,"Usage: %s [-t index|-T] [-b index] [-c comment|-C] [-l|-L|-V] [filename]\n",image); (void)fprintf(stderr,"Convert any GIF file into a GIF89a, with the folloing changes possible:\n"); (void)fprintf(stderr,"-t Specify the index of the transparent color within the color table\n"); (void)fprintf(stderr,"-T Index of the transparent color is the background color index\n"); (void)fprintf(stderr,"-b Specify the index of the background color within the color table\n"); (void)fprintf(stderr,"-c Add a comment\n"); (void)fprintf(stderr,"-C Remove old comment\n"); (void)fprintf(stderr,"-l Only list the color table\n"); (void)fprintf(stderr,"-L Verbose output of GIFs contents\n"); (void)fprintf(stderr,"-V Verbose output while converting\n"); (void)fprintf(stderr,"Colors may be specified as index, as rgb.txt entry or in the #rrggbb form.\n"); exit(1); } int main(argc,argv) int argc; char *argv[]; { int c; extern char *optarg; extern int optind; char error[2*MAXPATHLEN+14],line[BUFSIZ],*ptr,*nptr; struct entry **next; FILE *src; int stat; image=argv[0]; root=NULL; if ((src=fopen(rgb,"r"))) { next= &root; while (fgets(line,sizeof(line),src)) { *next=(struct entry *)malloc(sizeof(struct entry)); for (ptr=line;strchr(" \t",*ptr);ptr++); for (nptr=ptr;!strchr(" \t",*ptr);ptr++); *ptr++='\0'; (*next)->red=atoi(nptr); for (;strchr(" \t",*ptr);ptr++); for (nptr=ptr;!strchr(" \t",*ptr);ptr++); *ptr++='\0'; (*next)->green=atoi(nptr); for (;strchr(" \t",*ptr);ptr++); for (nptr=ptr;!strchr(" \t",*ptr);ptr++); *ptr++='\0'; (*next)->blue=atoi(nptr); for (;strchr(" \t",*ptr);ptr++); for (nptr=ptr;!strchr(" \t\r\n",*ptr);ptr++); *ptr='\0'; (void)strcpy((*next)->name=(char *)malloc(strlen(nptr)+1),nptr); (*next)->next=NULL; next= &(*next)->next; } (void)fclose(src); } else { (void)sprintf(error,"%s: cannot open %s",image,rgb); perror(error); return(FAILURE); } bc.index=NONE; tc.index=NONE; comment=NULL; skipcomment=FALSE; verbose=FALSE; while ((c=getopt(argc,argv,"t:Tb:c:ClLVvh?")) != EOF) switch ((char)c) { case 'b': if (getindex(&bc,optarg)) return(FAILURE); break; case 't': if (getindex(&tc,optarg)) return(FAILURE); break; case 'T': tc.index=OTHER; break; case 'c': comment=optarg; break; case 'C': skipcomment=TRUE; break; case 'l': list=TRUE; output=FALSE; break; case 'L': verbose=TRUE; output=FALSE; break; case 'V': verbose=TRUE; break; case 'v': (void)fprintf(stderr,header); return(0); case 'h': (void)fprintf(stderr,header); case '?': usage(); } if (optind+1