-#include <stdio.h>
+#include "statichuff.h"
+#include <stdlib.h>
-typedef unsigned short int t_freq;
-
-typedef struct t_freqnode {
- unsigned short int symbol;
- unsigned short int freq;
- struct t_freqnode *lchild;
- struct t_freqnode *rchild;
-} HUFFNODE;
+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;
-typedef struct t_code {
- unsigned short int code;
- unsigned char codelength;
-} CODE;
+ /* 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;
+ return;
+ }
+ /* me indican que comienza un nuevo output */
+ if (restart) {
+ bits_buffer = 0;
+ bits_used = 0;
+ }
+ /* inserto el bit en el buffer */
+ bits_buffer = bits_buffer << 1;
+ bits_buffer |= bit;
+ bits_used++;
+
+ /* lleno el buffer, escribo */
+ if (bits_used == 32) {
+ fwrite(&bits_buffer,sizeof(unsigned long int),1,fp);
+ bits_buffer = 0;
+ bits_used = 0;
+ }
+ return;
+}
-void cpynode(HUFFNODE *node1, HUFFNODE *node2)
+void shuff_cpynode(SHUFFNODE *node1, SHUFFNODE *node2)
{
node1->symbol = node2->symbol;
node1->freq = node2->freq;
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 -11;
+ 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;
- int totalfreq = 0;
+ t_freq totalfreq = 0;
/* Divido por la mitad las frecuencias, asegurando de no perder */
/* frequencias en 1, por ello le sumo 1 antes de partir */
for (i = 0; i < 256; i++) {
- freqtable[i] = (freqtable[i]+1)/2;
+ freqtable[i] = (freqtable[i] << 2) | 1;
totalfreq += freqtable[i];
}
return totalfreq;
}
-int scanfreq(char *inputfile, t_freq *freqtable)
+int shuff_scanfreq(char *inputfile, t_freq *freqtable)
{
/* Locals */
FILE *fp;
- int sumfreq = 0,auxsum = 0;
+ 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 */
++sumfreq;
/* Si llegue al tope de freq acumulada, halve em */
- if (sumfreq == 4181)
- sumfreq = rescalefreq(freqtable);
+ if (sumfreq == 14930352)
+ 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;
for (i = 0; i < 256; ++i) {
if (codetable[i].codelength > 0) {
auxcode = codetable[i].code;
- printf("Symbol:%i Freq: %i Code:",i,freqtable[i]);
+ printf("Symbol:%i Freq: %li Code:",i,freqtable[i]);
for (j = codetable[i].codelength-1; j >= 0; --j) {
auxcode = codetable[i].code;
auxcode = auxcode >> j;
}
}
-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 */
table[node->symbol].code = code;
- table[node->symbol].codelength = level;
- /*printf("Found symbol %i with freq %i at depth %i\n",node->symbol,node->freq,level);*/
+ table[node->symbol].codelength = level;
}
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;
- }
+
+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;
+ SHUFFCODE symbolcode;
- /* Devuelvo el puntero a la raiz del arbol de huffman */
- return lastsymbol;
+ /* 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);
+
+ /* 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 = ctable[symbol];
+ for (i = symbolcode.codelength; i > 0; --i) {
+ bit = (symbolcode.code >> (i-1)) & 1;
+ putbit(bit,0,0,fpdest);
+ }
+ }
+
+ /* Hacemos un flush de lo que haya quedado en el buffer de salida */
+ putbit(0,0,1,fpdest);
+ fclose(fpsource);
+ fclose(fpdest);
+ 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);
- zerocodes(codetable);
- buildcodes(codetable,codetree,0,0);
- printcodes(codetable,freqtable);
- /*encode(codetable)*/
+ inputlist = shuff_buildlist(freqtable, &freqcount);
+ codetree = shuff_buildtree(inputlist,freqcount);
+
+ /* Armo la tabla de codigos prefijos para el encoder */
+ 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;
- return 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;
}
projects / z.facultad / 75.06 / jacu.git / blobdiff