]> git.llucax.com Git - z.facultad/75.06/jacu.git/commitdiff
Reordeno un poco el codigo para hacerlo mas modular, igualmente en cuanto vea el...
authorAlan Kennedy <kennedya@3dgames.com.ar>
Sat, 19 Jun 2004 23:07:16 +0000 (23:07 +0000)
committerAlan Kennedy <kennedya@3dgames.com.ar>
Sat, 19 Jun 2004 23:07:16 +0000 (23:07 +0000)
src/statichuff/statichuff.c
src/statichuff/statichuff.h [new file with mode: 0644]

index e91a367b1bba115a4f763cd417f2d1de9ed7f3cb..540800d2dda6bca61fb0b8770cbd31585238acbc 100644 (file)
@@ -1,27 +1,15 @@
 
-#include <stdio.h>
-
-typedef unsigned long int t_freq;
-
-typedef struct t_freqnode {
-       unsigned short int symbol;
-       t_freq freq;
-       struct t_freqnode *lchild;
-       struct t_freqnode *rchild;
-} HUFFNODE;
-
-typedef struct t_code {
-       unsigned long int code;
-       unsigned char codelength;
-} CODE;
+#include "statichuff.h"
 
 void putbit(char bit, char restart, char flush, FILE *fp)
 {
        static unsigned long int bits_buffer = 0;
        static unsigned char bits_used = 0;
+       int i;
 
-       /* me obligan a tirar el output */
+       /* me obligan a emitir el output */
        if ((flush == 1) && (bits_used > 0)) {
+               bits_buffer = bits_buffer << ((sizeof(unsigned long int)*8) - bits_used);
                fwrite(&bits_buffer,sizeof(unsigned long int),1,fp);
                bits_buffer = 0;
                bits_used = 0;
@@ -46,7 +34,7 @@ void putbit(char bit, char restart, char flush, FILE *fp)
        return;
 }
 
-void cpynode(HUFFNODE *node1, HUFFNODE *node2)
+void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2)
 {
        node1->symbol = node2->symbol;
        node1->freq = node2->freq;
@@ -54,37 +42,14 @@ void cpynode(HUFFNODE *node1, HUFFNODE *node2)
        node1->rchild = node2->rchild;  
 }
 
-int compnode(HUFFNODE *node1, HUFFNODE *node2)
+int shuff_compnode(SHUFFNODE *node1, SHUFFNODE *node2)
 {      
        if (node1->freq < node2->freq) return 1;
        if (node1->freq > node2->freq) return -1;
        return 0;
 }
 
-HUFFNODE *buildlist(t_freq *freqtable, int *nonzerofreqs)
-{
-       int i,j = 0,nonzero = 0;        
-       HUFFNODE *inputlist;
-       
-       /* Calculo cuantas frequencias > 0 hay y creo la tabla */
-       for (i = 0; i < 256; ++i) if (freqtable[i] > 0) nonzero++;
-       inputlist = (HUFFNODE*)malloc(sizeof(HUFFNODE)*nonzero);
-               
-       /* Cargo la inputlist del huffman solo con freqs > 0 */
-       for (i = 0; i < 256; ++i)
-               if (freqtable[i] > 0) {                 
-                       inputlist[j].symbol = i;
-                       inputlist[j].freq = freqtable[i];
-                       inputlist[j].lchild = NULL;
-                       inputlist[j].rchild = NULL;                     
-                       j++;
-               }
-               
-       *nonzerofreqs = nonzero;
-       return inputlist;
-}
-
-int rescalefreq(t_freq *freqtable)
+int shuff_rescalefreq(t_freq *freqtable)
 { 
        int i;
        t_freq totalfreq = 0;
@@ -99,14 +64,14 @@ int rescalefreq(t_freq *freqtable)
        return totalfreq;
 }
 
-int scanfreq(char *inputfile, t_freq *freqtable)
+int shuff_scanfreq(char *inputfile, t_freq *freqtable)
 {
        /* Locals */    
        FILE *fp;
        t_freq sumfreq = 0;
        int i,symbol;
        
-       /* Inicializamos la tabla de frecuencias */
+       /* Inicializamos la tabla de frecuencias */     
        for (i = 0; i < 256; ++i) freqtable[i] = 0;
                
        /* Abrimos el file */
@@ -121,14 +86,64 @@ int scanfreq(char *inputfile, t_freq *freqtable)
                                
                /* Si llegue al tope de freq acumulada, halve em */
                if (sumfreq == 14930352) 
-                       sumfreq = rescalefreq(freqtable);
+                       sumfreq = shuff_rescalefreq(freqtable);
        }
        
        fclose(fp);
        return 1;       
 }
 
-void printcodes(CODE *codetable,t_freq *freqtable)
+SHUFFNODE *shuff_buildlist(t_freq *freqtable, int *nonzerofreqs)
+{
+       int i,j = 0,nonzero = 0;        
+       SHUFFNODE *inputlist;
+       
+       /* Calculo cuantas frequencias > 0 hay y creo la tabla */
+       for (i = 0; i < 256; ++i) if (freqtable[i] > 0) nonzero++;
+       inputlist = (SHUFFNODE*)malloc(sizeof(SHUFFNODE)*nonzero);
+               
+       /* Cargo la inputlist del huffman solo con freqs > 0 */
+       for (i = 0; i < 256; ++i)
+               if (freqtable[i] > 0) {                 
+                       inputlist[j].symbol = i;
+                       inputlist[j].freq = freqtable[i];
+                       inputlist[j].lchild = NULL;
+                       inputlist[j].rchild = NULL;                     
+                       j++;
+               }
+               
+       *nonzerofreqs = nonzero;
+       return inputlist;
+}
+
+SHUFFNODE *shuff_buildtree(SHUFFNODE *list, int listcount)
+{
+       SHUFFNODE *lastsymbol = list+(listcount-1);
+       SHUFFNODE *node1,*node2,*fictnode;
+
+       /* Ordenamos inicialmente la inputlist para tomar las dos freqs min */
+       while (lastsymbol > list) {             
+               /* Ordeno la lista por frecuencia descendente */
+               qsort(list,listcount,sizeof(SHUFFNODE),shuff_compnode);                         
+               /* Tomo los ultimos dos elementos, generando dos nodos del arbol */
+               node1 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
+               node2 = (SHUFFNODE*)malloc(sizeof(SHUFFNODE));
+               shuff_cpynode(node1,lastsymbol-1);
+               shuff_cpynode(node2,lastsymbol);                
+               lastsymbol -= 1;
+               /* Nodo ficticio con la suma de las probs y los ptros a childs */
+               lastsymbol->symbol = 256;
+               lastsymbol->freq = node1->freq + node2->freq;
+               lastsymbol->lchild = node1;
+               lastsymbol->rchild = node2;
+               --listcount;
+       }
+               
+       /* Devuelvo el puntero a la raiz del arbol de huffman */
+       return lastsymbol;
+}
+
+void shuff_printcodes(SHUFFCODE *codetable,t_freq *freqtable)
 {
        int i,j;
        unsigned short int auxcode;
@@ -149,18 +164,18 @@ void printcodes(CODE *codetable,t_freq *freqtable)
        }
 }
 
-void zerocodes(CODE *table)
+void shuff_zerocodes(SHUFFCODE *table)
 {
        int i;
        
-       /* Inicializo los codigos prefijos */
+       /* Inicializo los codigos prefijos */   
        for (i = 0; i < 256; ++i) {
                table[i].code = 0;
                table[i].codelength = 0;
        }
 }
 
-void buildcodes(CODE *table, HUFFNODE *node, int level, int code)
+void shuff_buildcodes(SHUFFCODE *table, SHUFFNODE *node, int level, int code)
 {
        if (node->symbol < 256) {
                /* Guardo el codigo en la tabla */
@@ -169,57 +184,41 @@ void buildcodes(CODE *table, HUFFNODE *node, int level, int code)
        }
        else {
                code = code << 1;
-               buildcodes(table,node->lchild,level+1,code);
+               shuff_buildcodes(table,node->lchild,level+1,code);
                code |= 1;
-               buildcodes(table,node->rchild,level+1,code);
+               shuff_buildcodes(table,node->rchild,level+1,code);
        }
 }
 
-HUFFNODE *buildtree(HUFFNODE *list, int listcount)
-{
-       HUFFNODE *lastsymbol = list+(listcount-1);
-       HUFFNODE *node1,*node2,*fictnode;
 
-       /* Ordenamos inicialmente la inputlist para tomar las dos freqs min */
-       while (lastsymbol > list) {             
-               /* Ordeno la lista por frecuencia descendente */
-               qsort(list,listcount,sizeof(HUFFNODE),compnode);                                
-               /* Tomo los ultimos dos elementos, generando dos nodos del arbol */
-               node1 = (HUFFNODE*)malloc(sizeof(HUFFNODE));
-               node2 = (HUFFNODE*)malloc(sizeof(HUFFNODE));
-               cpynode(node1,lastsymbol-1);
-               cpynode(node2,lastsymbol);              
-               lastsymbol -= 1;
-               /* Nodo ficticio con la suma de las probs y los ptros a childs */
-               lastsymbol->symbol = 256;
-               lastsymbol->freq = node1->freq + node2->freq;
-               lastsymbol->lchild = node1;
-               lastsymbol->rchild = node2;
-               --listcount;
-       }
-               
-       /* Devuelvo el puntero a la raiz del arbol de huffman */
-       return lastsymbol;
-}
 
-int encode(CODE *table, char* inputfile, char *outputfile) {
+int shuff_encode_symbols(t_freq *ftable, SHUFFCODE *ctable, char* inputfile, char *outputfile) {
 
        FILE *fpsource,*fpdest;
        int symbol,i;
+       unsigned long int sourcesize;
        char bit;
-       CODE symbolcode;
+       SHUFFCODE symbolcode;
                
        /* Abrimos el file */
        if ((fpsource = fopen(inputfile,"rb")) == NULL) return 0;
        if ((fpdest = fopen(outputfile,"wb")) == NULL) return 0;
+               
+       /* Guardamos el size el archivo original e inputlist como header */
+       fseek(fpsource,0,SEEK_END);
+       sourcesize = ftell(fpsource);
+       fwrite(&sourcesize,sizeof(unsigned long int),1,fpdest);
+       fwrite(ftable,sizeof(t_freq),256,fpdest);
        
-       while (!feof(fpsource)) {               
+       /* Encodeo */
+       fseek(fpsource,0,SEEK_SET);
+       while (!feof(fpsource)) {
                /* Levanto un symbolo (byte) */         
                symbol = fgetc(fpsource);
                if (symbol == EOF) continue;
                
                /* Cargamos el codigo y lo emitimos */
-               symbolcode = table[symbol];
+               symbolcode = ctable[symbol];
                for (i = symbolcode.codelength; i > 0; --i) {
                        bit = (symbolcode.code >> (i-1)) & 1;
                        putbit(bit,0,0,fpdest);
@@ -233,28 +232,64 @@ int encode(CODE *table, char* inputfile, char *outputfile) {
        return 1;       
 }
 
-int main(int argc, char* argv[])
+int shuff_encode_file(char *inputfile, char *outputfile)
 {
        /* Locals */
        t_freq *freqtable = (t_freq*)malloc(sizeof(t_freq)*256);
-       HUFFNODE *inputlist;
-       HUFFNODE *codetree;
-       CODE *codetable = (CODE*)malloc(sizeof(CODE)*256);
+       SHUFFNODE *inputlist;
+       SHUFFNODE *codetree;
+       SHUFFCODE *codetable = (SHUFFCODE*)malloc(sizeof(SHUFFCODE)*256);
        int freqcount = 0,i;
        
-       if (argc == 1) return -1;
-       
        /* Armamos la tabla de frecuencias */
-       if (!scanfreq(argv[1],freqtable)) return -1;
+       if (!shuff_scanfreq(inputfile,freqtable)) return -1;
        
        /* Armo el input list y genero el arbol de huffman */
-       inputlist = buildlist(freqtable, &freqcount);   
-       codetree = buildtree(inputlist,freqcount);
+       inputlist = shuff_buildlist(freqtable, &freqcount);
+       codetree = shuff_buildtree(inputlist,freqcount);
+
        /* Armo la tabla de codigos prefijos para el encoder */
-       zerocodes(codetable);
-       buildcodes(codetable,codetree,0,0);
-       printcodes(codetable,freqtable);
-       encode(codetable,argv[1],"output.dat");
+       shuff_zerocodes(codetable);
+       shuff_buildcodes(codetable,codetree,0,0);
+       shuff_printcodes(codetable,freqtable);
+
+       /* Encodeo byte per byte */
+       shuff_encode_symbols(freqtable,codetable,inputfile,outputfile);
+}
+
+int shuff_decode(char *inputfile, char *outputfile)
+{
+       SHUFFNODE *inputlist;
+       SHUFFNODE *codetree;
+       t_freq *ftable = (t_freq*)malloc(sizeof(t_freq)*256);
+       unsigned long int bytesleft;
+       FILE *fpsource;
+       FILE *fpdest;
+       int i,freqcount = 0;
+       
+       /* Levanto cuantos bytes decodeo y la freq table */
+       if ((fpsource = fopen(inputfile,"rb")) == NULL) return 0;
+       if ((fpdest = fopen(outputfile,"wb")) == NULL) return 0;
+       fread(&bytesleft,sizeof(unsigned long int),1,fpsource);
+       fread(ftable,sizeof(unsigned long int),256,fpsource);
+       inputlist = shuff_buildlist(ftable, &freqcount);
+       codetree = shuff_buildtree(inputlist,freqcount);
+               
+       fclose(fpsource);
+       fclose(fpdest);
+       
+       
+}
+
+int main(int argc, char* argv[])
+{      
+       if (argc == 1) return -1;
+               
+       /* Comprimo */
+       shuff_encode_file(argv[1],"output.shf");        
+
+       /* Decodeo */
+       shuff_decode("output.shf","decoded.dat");
        
        return 0;
 }
diff --git a/src/statichuff/statichuff.h b/src/statichuff/statichuff.h
new file mode 100644 (file)
index 0000000..eac6505
--- /dev/null
@@ -0,0 +1,16 @@
+
+#include <stdio.h>
+
+typedef unsigned long int t_freq;
+
+typedef struct t_freqnode {
+       unsigned short int symbol;
+       t_freq freq;
+       struct t_freqnode *lchild;
+       struct t_freqnode *rchild;
+} SHUFFNODE;
+
+typedef struct t_code {
+       unsigned long int code;
+       unsigned char codelength;
+} SHUFFCODE;