diff options
Diffstat (limited to 'camlibs/jd11/decomp.c')
| -rw-r--r-- | camlibs/jd11/decomp.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/camlibs/jd11/decomp.c b/camlibs/jd11/decomp.c new file mode 100644 index 000000000..fd740e79d --- /dev/null +++ b/camlibs/jd11/decomp.c @@ -0,0 +1,171 @@ +/* + * Jenoptik JD11 Camera Driver + * Copyright © 1999-2001 Marcus Meissner <marcus@jet.franken.de> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#include "config.h" +#include <stdio.h> +#include <string.h> +#include <assert.h> +#include <stdlib.h> +#include <unistd.h> + +#include "decomp.h" + +struct chain { int left,val,right; }; +struct compstate { + unsigned char curmask; + unsigned char bytebuf; + unsigned char *byteptr; + + struct chain cl[200]; + int stackstart; +}; + +/* FLOAT_QUERY: 0.860000 1.030000 1.150000. */ + +/********************************************************/ +/* The bit stage */ +/********************************************************/ +static inline int +jd11_getbit(struct compstate *cs) { + int ret; + if (cs->curmask == 0x80) + cs->bytebuf = *cs->byteptr++; + ret = cs->curmask & cs->bytebuf; + cs->curmask >>=1; + if (!cs->curmask) cs->curmask = 0x80; + return !!ret; +} + +/********************************************************/ +/* The huffman compressor stage */ +/********************************************************/ +static int +decomp_1byte(struct compstate *cs) { + int xcs = cs->stackstart; + int xbit; + + while ((cs->cl[xcs].left>=0) && (cs->cl[xcs].right>=0)) { + xbit = jd11_getbit(cs); + if (xbit) + xcs = cs->cl[xcs].left; + else + xcs = cs->cl[xcs].right; + } + return cs->cl[xcs].val; +} + +static void +build_huffmann_tree(struct compstate *cs) { + int xstack[200]; + int i,curcl=0,curstack=0; + const int df[] = { + -180,180,1000,-90,1000,90,1000,-45,1000,45,1000,-20,1000, + 20,1000,-11,1000,11,1000,-6,1000,2,1000,6,-2,1000,1000 + }; + for (i=0;i<sizeof(df)/sizeof(df[0]);i++) { + if (df[i]!=1000) { + cs->cl[curcl].left = -1; + cs->cl[curcl].right = -1; + cs->cl[curcl].val = df[i]; + } else { + cs->cl[curcl].right = xstack[--curstack]; + cs->cl[curcl].left = xstack[--curstack]; + } + xstack[curstack++] = curcl++; + } + cs->stackstart = xstack[0]; +} + +#define F1 0.5 +#define F2 0.0 +#define F3 0.5 +#define F4 0.0 + +void +picture_decomp_v1(char *compressed,char *uncompressed,int width,int height) { + struct compstate cs; + unsigned char xbyte; + int i=0,curbyte=0,diff,lastval; + int *line,*lastline; + + cs.curmask = 0x80; cs.bytebuf = 0; cs.byteptr = compressed; + + build_huffmann_tree(&cs); + + line = (int*)malloc(sizeof(int)*width); + lastline= (int*)malloc(sizeof(int)*width); + curbyte=0; + memset(line,0,sizeof(line)); + memset(lastline,0,sizeof(line)); + for (i=0;i<width;i++) { + diff = decomp_1byte(&cs); + curbyte+=diff; + xbyte = curbyte; + if (curbyte>255) xbyte = 255; + if (curbyte<0) xbyte = 0; + + *uncompressed++=xbyte; + + line[i] = curbyte; + } + height--; + while (height--) { + lastval = line[0]; /* just before the copy */ + memcpy(lastline,line,width*sizeof(int)); + memset(line,0,width*sizeof(int)); + for (i=0;i<width;i++) { + diff = decomp_1byte(&cs); + line[i]=diff+lastval; + if (i<width-2) { + lastval = (int)((lastline[i+2]*F4+lastline[i]*F2+lastline[i+1]*F1+line[i]*F3)); + } else { + if (i==width-2) + lastval = (int)(lastline[i]*F2+lastline[i+1]*F1+line[i]*F3); + else + lastval = line[i]; + } + + xbyte = line[i]; + if (line[i]>255) xbyte = 255; + if (line[i]<0) xbyte = 0; + *uncompressed++=xbyte; + } + } +} + +/* Just blow up the picture from 6 bit uncompressed to 8 bit uncompressed */ +void +picture_decomp_v2(char *compressed,char *uncompressed,int width,int height) { + struct compstate cs; + int i,j; + unsigned char xbyte; + + cs.curmask = 0x80; cs.bytebuf = 0; cs.byteptr = compressed; + for (i=width*height;i--;) { + unsigned char xmask = 0x80; + xbyte = 0; + for (j=6;j--;) { + if (jd11_getbit(&cs)) + xbyte|=xmask; + xmask>>=1; + } + *uncompressed++=xbyte; + } +} |