diff --git a/src/modules/Image/encodings/gif.c b/src/modules/Image/encodings/gif.c
index 61ded9f443e03e9a7ed76519854fdc41054c1399..1af9fd57a97f6bfa82a2b44e8bc20a6d76742243 100644
--- a/src/modules/Image/encodings/gif.c
+++ b/src/modules/Image/encodings/gif.c
@@ -1,9 +1,9 @@
-/* $Id: gif.c,v 1.42 1998/04/16 23:47:54 hubbe Exp $ */
+/* $Id: gif.c,v 1.43 1998/04/29 01:27:20 mirar Exp $ */
/*
**! module Image
**! note
-**! $Id: gif.c,v 1.42 1998/04/16 23:47:54 hubbe Exp $
+**! $Id: gif.c,v 1.43 1998/04/29 01:27:20 mirar Exp $
**! submodule GIF
**!
**! This submodule keep the GIF encode/decode capabilities
@@ -31,7 +31,7 @@
#include <ctype.h>
#include "stralloc.h"
-RCSID("$Id: gif.c,v 1.42 1998/04/16 23:47:54 hubbe Exp $");
+RCSID("$Id: gif.c,v 1.43 1998/04/29 01:27:20 mirar Exp $");
#include "pike_macros.h"
#include "object.h"
#include "constants.h"
@@ -1595,13 +1595,6 @@ static void _gif_decode_lzw(unsigned char *s,
{
struct neo_colortable *nct;
- struct lzwc
- {
- unsigned short prev;
- unsigned short len;
- unsigned short c;
- } *c;
-
rgb_group white={255,255,255},black={0,0,0};
int bit=0,bits=obits+1;
@@ -1647,7 +1640,7 @@ fprintf(stderr,"_gif_decode_lzw(%lx,%lu,%d,%lx,%lx,%lx,%lu,%d)\n",
bit-=bits;
#ifdef GIF_DEBUG
- if (debug) fprintf(stderr,"code=%d 0x%x bits=%d\n",n,n,bits);
+ if (debug) fprintf(stderr,"code=%d 0x%02x bits=%d\n",n,n,bits);
#endif
if (n==m)
@@ -2292,6 +2285,244 @@ void image_gif__encode(INT32 args)
f_add(n); /* add the strings */
}
+/** lzw stuff ***************************************************/
+
+static void image_gif_lzw_encode(INT32 args)
+{
+ struct gif_lzw lzw;
+
+ if (!args || sp[-args].type!=T_STRING)
+ error("Image.GIF.lzw_encode(): illegal argument\n");
+
+ image_gif_lzw_init(&lzw,8);
+ if (lzw.broken) error("out of memory\n");
+
+ if (args>=2 && !IS_ZERO(sp+1-args))
+ lzw.earlychange=1;
+
+ if (args>=3 && !IS_ZERO(sp+2-args))
+ lzw.reversebits=1;
+
+ image_gif_lzw_add(&lzw,
+ (unsigned char *)sp[-args].u.string->str,
+ sp[-args].u.string->len);
+
+ image_gif_lzw_finish(&lzw);
+
+ if (lzw.broken) error("out of memory\n");
+
+ pop_n_elems(args);
+ push_string(make_shared_binary_string((char*)lzw.out,lzw.outpos));
+}
+
+static void image_gif_lzw_decode(INT32 args)
+{
+ unsigned char *s,*dest0,*dest;
+ int earlychange=0;
+ unsigned long len,n;
+ signed long clearcode,endcode,last,q,bit,m,dlen,dlen0;
+ unsigned int mask;
+ struct lzwc *c;
+ signed long bits,obits=8;
+ signed long maxcode;
+ int reversebits=0;
+
+ if (!args || sp[-args].type!=T_STRING)
+ error("Image.GIF.lzw_encode(): illegal argument\n");
+
+ s=(unsigned char*)sp[-args].u.string->str;
+ len=(unsigned long)sp[-args].u.string->len;
+
+ if (args>=2 && !IS_ZERO(sp+1-args))
+ earlychange=1;
+ if (args>=3 && !IS_ZERO(sp+2-args))
+ reversebits=1;
+
+ if (len<1)
+ {
+ pop_n_elems(args);
+ push_string(make_shared_binary_string("",0));
+ return;
+ }
+
+ clearcode=(1<<obits);
+ endcode=clearcode+1;
+ bits=obits+1;
+ mask=(unsigned short)((1<<bits)-1);
+ m=endcode;
+ maxcode=(1<<bits);
+
+ last=clearcode;
+
+ c=(struct lzwc*)xalloc(sizeof(struct lzwc)*MAX_GIF_CODE);
+
+ dest0=(unsigned char*)malloc(dlen0=len*4);
+ if (!dest0)
+ {
+ free(c);
+ error("Image.GIF.lzw_decode: out of memory\n");
+ }
+ dest=dest0; dlen=dlen0;
+
+ for (n=0; n<clearcode; n++)
+ c[n].prev=0xffff,c[n].len=1,c[n].c=n;
+ c[clearcode].len=0;
+ c[endcode].len=0;
+
+ if (len>1)
+ {
+ if (reversebits) q=s[1]|(s[0]<<8);
+ else q=s[0]|(s[1]<<8);
+ bit=16;
+ s+=2; len-=2;
+ }
+ else
+ {
+ q=s[0];
+ bit=8;
+ s+=1; len-=1;
+ }
+
+ while (bit>0)
+ {
+ /* get next code */
+
+#ifdef GIF_DEBUG
+ fprintf(stderr,"q=0x%04x bit=%2d bits=%2d ... ",q,bit,bits);
+#endif
+
+ if (reversebits)
+ n=(q>>(bit-bits))&mask;
+ else
+ {
+ n=q&mask;
+ q>>=bits;
+ }
+ bit-=bits;
+
+#ifdef GIF_DEBUG
+ fprintf(stderr,"code=%3d 0x%02x bits=%d bit=%2d *s=0x%02x len=%d\n",n,n,bits,bit,*s,len);
+#endif
+
+ if (n==m)
+ {
+ c[n].prev=last;
+ c[n].c=c[last].c;
+ c[n].len=c[last].len+1;
+ }
+ else if (n>=m)
+ {
+#ifdef GIF_DEBUG
+ fprintf(stderr,"cancel; illegal code, %d>=%d at %lx\n",n,m,s);
+#endif
+ break; /* illegal code */
+ }
+ if (!c[n].len)
+ if (n==clearcode)
+ {
+ bits=obits+1;
+ mask=(1<<bits)-1;
+ m=endcode;
+ last=clearcode;
+ maxcode=1<<bits;
+ }
+ else
+ {
+ /* endcode */
+#ifdef GIF_DEBUG
+ fprintf(stderr,"endcode at %lx\n",s);
+#endif
+ break;
+ }
+ else
+ {
+ struct lzwc *myc;
+ unsigned char *d;
+ unsigned short lc;
+ myc=c+n;
+
+ if (myc->len>dlen)
+ {
+ signed long p;
+ p=(dest-dest0);
+
+#ifdef GIF_DEBUG
+ fprintf(stderr,"increase at dlen left=%lu p=%ld dlen0=%d\n",dlen,p,dlen0);
+#endif
+ dest=realloc(dest0,dlen0*2);
+ if (!dest)
+ {
+ dest=dest0+p;
+ break; /* out of memory */
+ }
+ dest0=dest;
+ dest=dest0+p;
+ dlen+=dlen0;
+ dlen0+=dlen0;
+
+#ifdef GIF_DEBUG
+ fprintf(stderr,"increase at dlen left=%lu p=%ld dlen0=%d\n",dlen,dest-dest0,dlen0);
+#endif
+ }
+
+ d=(dest+=myc->len);
+ dlen-=myc->len;
+
+ for (;;)
+ {
+ lc=myc->c;
+ *(--d)=(unsigned char)lc;
+ if (myc->prev==0xffff) break;
+ myc=c+myc->prev;
+ }
+
+ if (last!=clearcode)
+ {
+ c[m].prev=last;
+ c[m].len=c[last].len+1;
+ c[m].c=lc;
+ }
+ last=n;
+
+ m++;
+ if (m>=maxcode - earlychange)
+ if (m==MAX_GIF_CODE - earlychange)
+ {
+#ifdef GIF_DEBUG
+ fprintf(stderr,"too many codes at %lx\n",s);
+#endif
+ m--;
+ bits=12;
+ }
+ else
+ {
+ bits++;
+ mask=(1<<bits)-1;
+ maxcode<<=1;
+ if (maxcode>MAX_GIF_CODE)
+ {
+#ifdef GIF_DEBUG
+ fprintf(stderr,"cancel; gif codes=%ld m=%ld\n",maxcode,m);
+#endif
+ break; /* error! too much codes */
+ }
+ }
+ }
+
+ if (reversebits)
+ while (bit<bits && len)
+ q=(q<<8)|(*s),bit+=8,s++,len--;
+ else
+ while (bit<bits && len)
+ q|=((*s)<<bit),bit+=8,s++,len--;
+ }
+ free(c);
+
+ pop_n_elems(args);
+ push_string(make_shared_binary_string((char*)dest0,dest-dest0));
+ free(dest0);
+}
+
/** module *******************************************/
struct program *image_encoding_gif_program=NULL;
@@ -2334,6 +2565,11 @@ void init_image_gif(void)
add_function("_encode_extension",image_gif__encode_extension,
"function(array:string)",0);
+ add_function("lzw_encode",image_gif_lzw_encode,
+ "function(string,void|int,void|int:string)",0);
+ add_function("lzw_decode",image_gif_lzw_decode,
+ "function(string,void|int,void|int:string)",0);
+
/** constants **/
add_integer_constant("RENDER",GIF_RENDER,0);
diff --git a/src/modules/Image/encodings/gif_lzw.c b/src/modules/Image/encodings/gif_lzw.c
index 916e8ef62c0557023322d2bef61bd24b3e85c833..13ffa228307d986ae68acd254c227295851e6f76 100644
--- a/src/modules/Image/encodings/gif_lzw.c
+++ b/src/modules/Image/encodings/gif_lzw.c
@@ -1,7 +1,7 @@
/*
**! module Image
**! note
-**! $Id: gif_lzw.c,v 1.4 1997/11/05 03:42:50 mirar Exp $
+**! $Id: gif_lzw.c,v 1.5 1998/04/29 01:27:22 mirar Exp $
*/
#include "global.h"
@@ -12,9 +12,6 @@
static INLINE void lzw_output(struct gif_lzw *lzw,lzwcode_t codeno)
{
- int bits,bitp;
- unsigned char c;
-
if (lzw->outpos+4>=lzw->outlen)
{
unsigned char *new;
@@ -23,31 +20,60 @@ static INLINE void lzw_output(struct gif_lzw *lzw,lzwcode_t codeno)
lzw->out=new;
}
- bitp=lzw->outbit;
- c=lzw->lastout;
- bits=lzw->codebits;
- if (bits>12) bits=12;
-
- while (bits)
+ if (!lzw->reversebits)
{
- c|=(codeno<<bitp);
- if (bits+bitp>=8)
+ int bits,bitp;
+ unsigned char c;
+
+ bitp=lzw->outbit;
+ c=(unsigned char)lzw->lastout;
+ bits=lzw->codebits;
+ if (bits>12) bits=12;
+
+ while (bits)
{
- bits-=8-bitp;
- codeno>>=8-bitp;
- bitp=0;
- lzw->out[lzw->outpos++]=c;
- c=0;
+ c|=(codeno<<bitp);
+ if (bits+bitp>=8)
+ {
+ bits-=8-bitp;
+ codeno>>=8-bitp;
+ bitp=0;
+ lzw->out[lzw->outpos++]=c;
+ c=0;
+ }
+ else
+ {
+ lzw->outbit=bitp+bits;
+ lzw->lastout=c;
+ return;
+ }
}
- else
+ lzw->lastout=0;
+ lzw->outbit=0;
+ }
+ else
+ {
+#ifdef GIF_DEBUG
+ fprintf(stderr,"codeno=%x lastout=%x outbit=%d codebits=%d\n",
+ codeno,lzw->lastout,lzw->outbit,lzw->codebits);
+#endif
+ lzw->lastout=(lzw->lastout<<lzw->codebits)|codeno;
+ lzw->outbit+=lzw->codebits;
+#ifdef GIF_DEBUG
+ fprintf(stderr,"-> codeno=%x lastout=%x outbit=%d codebits=%d\n",
+ codeno,lzw->lastout,lzw->outbit,lzw->codebits);
+#endif
+ while (lzw->outbit>8)
{
- lzw->outbit=bitp+bits;
- lzw->lastout=c;
- return;
+ lzw->out[lzw->outpos++] =
+ (unsigned char)(lzw->lastout>>(lzw->outbit-8));
+ lzw->outbit-=8;
+#ifdef GIF_DEBUG
+ fprintf(stderr,"(shiftout) codeno=%x lastout=%x outbit=%d codebits=%d\n",
+ codeno,lzw->lastout,lzw->outbit,lzw->codebits);
+#endif
}
}
- lzw->lastout=0;
- lzw->outbit=0;
}
static INLINE void lzw_add(struct gif_lzw *lzw,int c)
@@ -103,7 +129,8 @@ static INLINE void lzw_add(struct gif_lzw *lzw,int c)
lzw->code[lzw->current].firstchild=lno2;
lzw->codes++;
- if (lzw->codes>(unsigned long)(1L<<lzw->codebits)) lzw->codebits++;
+ if (lzw->codes+lzw->earlychange>(unsigned long)(1L<<lzw->codebits))
+ lzw->codebits++;
lzw->current=c;
}
@@ -134,6 +161,8 @@ void image_gif_lzw_init(struct gif_lzw *lzw,int bits)
lzw->current=LZWCNULL;
lzw->outbit=0;
lzw->lastout=0;
+ lzw->earlychange=0;
+ lzw->reversebits=0;
lzw_output(lzw,1L<<bits);
}
@@ -143,7 +172,12 @@ void image_gif_lzw_finish(struct gif_lzw *lzw)
lzw_output(lzw,lzw->current);
lzw_output( lzw, (1L<<lzw->bits)+1 ); /* GIF end code */
if (lzw->outbit)
- lzw->out[lzw->outpos++]=lzw->lastout;
+ {
+ if (lzw->reversebits)
+ lzw->out[lzw->outpos++]=lzw->lastout<<(8-lzw->outbit);
+ else
+ lzw->out[lzw->outpos++]=lzw->lastout;
+ }
}
void image_gif_lzw_free(struct gif_lzw *lzw)
diff --git a/src/modules/Image/encodings/gif_lzw.h b/src/modules/Image/encodings/gif_lzw.h
index b50e2f3ea3f7c2bed5ff3dc1d4449f95fb584937..7555d1ada98698aad0c3fd5408f470d7628e9c71 100644
--- a/src/modules/Image/encodings/gif_lzw.h
+++ b/src/modules/Image/encodings/gif_lzw.h
@@ -1,19 +1,29 @@
/*
**! module Image
**! note
-**! $Id: gif_lzw.h,v 1.4 1997/11/02 03:44:51 mirar Exp $
+**! $Id: gif_lzw.h,v 1.5 1998/04/29 01:27:23 mirar Exp $
*/
typedef unsigned short lzwcode_t; /* no more than 12 bits used */
#define LZWCNULL ((lzwcode_t)(~0))
+struct lzwc
+{
+ unsigned short prev;
+ unsigned short len;
+ unsigned short c;
+} *c;
+
struct gif_lzw
{
int broken; /* lzw failed, out of memory */
- unsigned char *out,lastout;
- unsigned long outlen;
+ unsigned char *out;
+ unsigned long outlen,lastout;
+ int earlychange;
+ int reversebits;
+
unsigned long codes;
unsigned long bits; /* initial encoding bits */
unsigned long codebits; /* current encoding bits */