From a630bec3eb1bed70c9b1a4628e87708f02ab4304 Mon Sep 17 00:00:00 2001
From: "Mirar (Pontus Hagland)" <pike@sort.mirar.org>
Date: Sun, 30 May 1999 22:11:15 +0200
Subject: [PATCH] (Image.GIF) added support for crippled lzw, some kind of rle
Rev: src/configure.in:1.294
Rev: src/modules/Image/encodings/gif_lzw.c:1.6
Rev: src/modules/Image/encodings/gif_lzw.h:1.7
---
src/configure.in | 3 ++-
src/modules/Image/encodings/gif_lzw.c | 39 ++++++++++++++++++++++-----
src/modules/Image/encodings/gif_lzw.h | 6 ++++-
3 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/src/configure.in b/src/configure.in
index d6ac27bbc0..486079734f 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -1,4 +1,4 @@
-AC_REVISION("$Id: configure.in,v 1.293 1999/05/29 15:20:51 grubba Exp $")
+AC_REVISION("$Id: configure.in,v 1.294 1999/05/30 20:11:12 mirar Exp $")
AC_INIT(interpret.c)
AC_CONFIG_HEADER(machine.h)
@@ -284,6 +284,7 @@ AC_ARG_WITH(threads, [ --without-threads no threads support],[],[with_
AC_ARG_WITH(zlib, [ --without-zlib no gz compression support],[],[with_zlib=yes])
AC_ARG_WITH(ssleay, [ --without-ssleay no support for the secure socket protocol],[],[with_ssleay=yes])
AC_ARG_WITH(mysql, [ --without-mysql no support for the Mysql database],[],[with_mysql=yes])
+AC_ARG_WITH(gif-rle, [ --with-gif-rle use kind-of-rle packing instead of lzw],[],[])
AC_ARG_WITH(dmalloc, [ --with-dmalloc enable memory-leak tests],[AC_DEFINE(DEBUG_MALLOC,10)],[])
AC_ARG_WITH(checker, [ --with-checker add extra memory checking overhead (Purify)])
AC_ARG_WITH(profiling, [ --with-profiling add code used to profile pike code ],[AC_DEFINE(PROFILING)],[])
diff --git a/src/modules/Image/encodings/gif_lzw.c b/src/modules/Image/encodings/gif_lzw.c
index 13ffa22830..4cd1b40023 100644
--- a/src/modules/Image/encodings/gif_lzw.c
+++ b/src/modules/Image/encodings/gif_lzw.c
@@ -1,10 +1,11 @@
/*
**! module Image
**! note
-**! $Id: gif_lzw.c,v 1.5 1998/04/29 01:27:22 mirar Exp $
+**! $Id: gif_lzw.c,v 1.6 1999/05/30 20:11:14 mirar Exp $
*/
#include "global.h"
+#include "image_machine.h"
#include "gif_lzw.h"
#define DEFAULT_OUTBYTES 16384
@@ -84,19 +85,37 @@ static INLINE void lzw_add(struct gif_lzw *lzw,int c)
if (lzw->current==LZWCNULL) /* no current, load */
{
lzw->current=c;
+#ifdef GIF_LZW_LZ
+ lzw->skipone=0;
+#endif
return;
}
- lno=lzw->code[lzw->current].firstchild; /* check if we have this sequence */
- while (lno!=LZWCNULL)
+#ifdef GIF_LZW_RLE
+ if (c==lzw->code[lzw->current].c)
{
- if (lzw->code[lno].c==c && lno!=lzw->codes-1 )
+#endif
+#ifdef GIF_LZW_LZ
+ if (!lzw->skipone)
{
- lzw->current=lno;
- return;
+#endif
+ /* check if we have this sequence */
+ lno=lzw->code[lzw->current].firstchild;
+ while (lno!=LZWCNULL)
+ {
+ if (lzw->code[lno].c==c && lno!=lzw->codes-1 )
+ {
+ lzw->current=lno;
+ return;
+ }
+ lno=lzw->code[lno].next;
+ }
+#ifdef GIF_LZW_RLE
}
- lno=lzw->code[lno].next;
+#endif
+#ifdef GIF_LZW_LZ
}
+#endif
if (lzw->codes==4096) /* needs more than 12 bits */
{
@@ -113,6 +132,9 @@ static INLINE void lzw_add(struct gif_lzw *lzw,int c)
lzw->codebits=lzw->bits+1;
lzw->current=c;
+#ifdef GIF_LZW_LZ
+ lzw->skipone=0;
+#endif
return;
}
@@ -133,6 +155,9 @@ static INLINE void lzw_add(struct gif_lzw *lzw,int c)
lzw->codebits++;
lzw->current=c;
+#ifdef GIF_LZW_LZ
+ lzw->skipone=!lzw->skipone;
+#endif
}
void image_gif_lzw_init(struct gif_lzw *lzw,int bits)
diff --git a/src/modules/Image/encodings/gif_lzw.h b/src/modules/Image/encodings/gif_lzw.h
index 6cfc993613..aa46fabe34 100644
--- a/src/modules/Image/encodings/gif_lzw.h
+++ b/src/modules/Image/encodings/gif_lzw.h
@@ -1,7 +1,7 @@
/*
**! module Image
**! note
-**! $Id: gif_lzw.h,v 1.6 1998/05/02 01:24:25 mirar Exp $
+**! $Id: gif_lzw.h,v 1.7 1999/05/30 20:11:15 mirar Exp $
*/
typedef unsigned short lzwcode_t; /* no more than 12 bits used */
@@ -23,6 +23,10 @@ struct gif_lzw
int earlychange;
int reversebits;
+
+#ifdef GIF_LZW_LZ
+ int skipone; /* lz marker for skip next code */
+#endif
unsigned long codes;
unsigned long bits; /* initial encoding bits */
--
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