This commit is contained in:
glenux 2005-10-30 20:56:05 +00:00
parent 21357f2fb5
commit 35180f6379
7 changed files with 175 additions and 77 deletions

View file

@ -7,7 +7,8 @@ lib_LTLIBRARIES = libeyd.la
libeyd_la_SOURCES = eyd_bitreader.cpp \
eyd_bitwriter.cpp \
eyd_bitgroup.cpp \
eyd_compressor.cpp
eyd_compressor.cpp \
eyd_uncompressor.cpp
libeyd_la_CFLAGS = -DTRACE
#-static

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@ -22,6 +22,7 @@ namespace EydLib {
BitCompressor::BitCompressor(int size) : _rle(size) {
_group_size = size;
_last_count = 0;
}
void BitCompressor::clear(){
@ -33,6 +34,8 @@ namespace EydLib {
void BitCompressor::flushRleData(){
BitGroup len(_group_size);
_compressed.push_back(_rle);
printf("Last count %d\n", _last_count);
printf("Max cellsize %d\n", len.maxValue());
len.setValue(_last_count);
_compressed.push_back(len);
_compressed.push_back(_last_group);

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@ -12,6 +12,7 @@
#include "eyd_bitreader.hh"
#include "eyd_bitwriter.hh"
#include "eyd_compressor.hh"
#include "eyd_uncompressor.hh"
#endif

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@ -0,0 +1,102 @@
#include "eyd_uncompressor.hh"
namespace EydLib {
/*
class BitUncompressor {
private:
BitGroup _last_group;
int _last_count;
std::list<BitGroup> _uncompressed;
public:
BitUncompressor();
void clear();
void append(BitGroup bg);
std::list<BitGroup> flush();
bool hasContent();
};
*/
BitUncompressor::BitUncompressor(int size) : _rle(size) {
_group_size = size;
_last_count = 0;
}
void BitUncompressor::clear(){
// we clear everything
_last_count = 0;
_uncompressed.clear();
}
void BitUncompressor::flushRleData(){
BitGroup len(_group_size);
_uncompressed.push_back(_rle);
printf("Last count %d\n", _last_count);
printf("Max cellsize %d\n", len.maxValue());
len.setValue(_last_count);
_uncompressed.push_back(len);
_uncompressed.push_back(_last_group);
_last_count = 0;
}
void BitUncompressor::flushRawData(){
int i;
for (i=0; i<_last_count; i++){
// on duplique les RLE trouvés
if (_last_group == _rle) {
_uncompressed.push_back(_last_group);
}
_uncompressed.push_back(_last_group);
}
_last_count = 0;
}
void BitUncompressor::append(BitGroup data){
// take the data and make it smaller...
if (_last_count > 0) {
// there are data in the compressor
if (data != _last_group){
// we have to empty the compressed list
if (_last_count < 4){
// not efficient
if ((_last_count > 1) && (_last_group == _rle)) {
// 1 RLE gives 2 RLE
// 2 RLE gives 4 RLE... let compress it...
this->flushRleData();
} else {
this->flushRawData();
}
} else {
// efficient ! lets compress it !
this->flushRleData();
}
} else {
// nothing to do... wait for another different data...
// maybe the count is bigger than the len-cell can store ?
if (_last_count >= _rle.maxValue()){
this->flushRleData();
}
}
} else {
// it is the first bitgroup
}
_last_group = data;
_last_count++;
}
std::list<BitGroup> BitUncompressor::flush(){
// we add the data from _last* to the outlist
std::list<BitGroup> result;
result = _uncompressed;
_uncompressed.clear();
return result;
}
bool BitUncompressor::hasContent(){
return (!_uncompressed.empty());
}
}

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@ -0,0 +1,41 @@
#ifndef _EYD_BITUNCOMPRESSOR_HH
#define _EYD_BITUNCOMPRESSOR_HH
#include <string>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <exception>
#include "eyd_bitgroup.hh"
#include "eyd_global.hh"
#include "eyd_iface.hh"
namespace EydLib {
class BitUncompressor {
private:
BitGroup _rle;
BitGroup _last_group;
int _last_count;
int _group_size;
std::list<BitGroup> _uncompressed;
public:
BitUncompressor::BitUncompressor(int size);
void clear();
void append(BitGroup bg);
std::list<BitGroup> flush();
bool hasContent();
void flushRleData();
void flushRawData();
};
}
#endif

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@ -2,7 +2,7 @@
SUBDIRS = .
bin_PROGRAMS = eyd bittest bitcopy bitcompress
bin_PROGRAMS = eyd bittest bitcopy bitcompress bitdecompress
eyd_SOURCES = eyd_console.cpp eyd_init.cpp
eyd_LDADD = -leyd
@ -33,6 +33,10 @@ bitcopy_SOURCES = bitcopy.cpp
bitcopy_LDADD = -leyd
bitcopy_LDFLAGS = @LDFLAGS@ -L../lib -L../lib/.libs
bitdecompress_SOURCES = bitdecompress.cpp
bitdecompress_LDADD = -leyd
bitdecompress_LDFLAGS = @LDFLAGS@ -L../lib -L../lib/.libs
bitcompress_SOURCES = bitcompress.cpp
bitcompress_LDADD = -leyd
bitcompress_LDFLAGS = @LDFLAGS@ -L../lib -L../lib/.libs

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@ -9,7 +9,7 @@ void usage(){
}
int main(int argc, char ** argv){
EydLib::BitGroup bg;
EydLib::BitGroup data;
int cell_size;
std::string original;
std::string copy;
@ -22,99 +22,45 @@ int main(int argc, char ** argv){
EydLib::BitReader bitread(cell_size, 256);
bitread.open(original);
unsigned char c;
bitread.readDirect(&c, 1);
//TODO: fixer cell_size en fonction de "c";
EydLib::BitWriter bitwrite(cell_size,256);
bitwrite.open(copy);
EydLib::BitGroup rleBg(cell_size);
EydLib::BitGroup lenBg(cell_size);
EydLib::BitUncompressor uncompressor(cell_size);
printf("Maximum value of cell : %d\n",lenBg.maxValue());
printf("File opened\n");
bool done=false;
std::vector<EydLib::BitGroup> record;
while(!done){
try{
bg = bitread.read();
printf("%s ",bg.toString().c_str());
fflush(stdout);
// on pousse le bit sur dans la file
if (record.size() == 0){
// on attend la suite...
} else {
EydLib::BitGroup tmpBg;
EydLib::BitGroup oldBg;
data = bitread.read();
uncompressor.append(data);
tmpBg = record.back();
// si le caractère est différent de celui d'avant
if (tmpBg != bg){
// on compte le nombre d'éléments
// on pose un marqueur
if (record.size()<3){
// FIXME: dans le cas de cellules "0" ?
// on ecrit les cellules telles quelles...
// si la taille est incompressible
for (int i=0; i<record.size(); i++){
oldBg = record[i];
if (oldBg.getValue() == 0){
// on échape le caractere avec un RLE
bitwrite.write(rleBg); // echapement
fprintf(stderr,"RLE ");
}
bitwrite.write(oldBg);
fprintf(stderr,"%s ",oldBg.toString().c_str());
}
record.clear();
} else {
// la cellule courante est différente de l'ancienne
// et la taille est compressible
bitwrite.write(rleBg); // echapement
fprintf(stderr,"RLE ");
lenBg.setValue(record.size());
bitwrite.write(lenBg); // longueur
fprintf(stderr,"%s ",lenBg.toString().c_str());
// on a pas besoind d'échaper le caractere avec un RLE
// parce qu'il est reconnaissable (2 places apres un RLE)
bitwrite.write(tmpBg); // cellule
fprintf(stderr,"%s ",tmpBg.toString().c_str());
// TODO: penser a calculer le taux de compression
record.clear();
}
} else {
// on ne fait rien car le caractère est le meme qu'avant
// sauf si la longueur est > a celle "enregistrable"
// par une cellule de donnée
if (record.size() >= rleBg.maxValue()){
// on flushe artificiellement
bitwrite.write(rleBg); // echapement
fprintf(stderr,"RLE ");
lenBg.setValue(record.size());
bitwrite.write(lenBg); // longueur
fprintf(stderr,"%s ",lenBg.toString().c_str());
// on a pas besoind d'échaper le caractere avec un RLE
// parce qu'il est reconnaissable (2 places apres un RLE)
bitwrite.write(tmpBg); // cellule
fprintf(stderr,"%s ",tmpBg.toString().c_str());
// TODO: penser a calculer le taux de compression
record.clear();
} else {
// sinon on ne fait rien, on a encore de la marge
}
if (uncompressor.hasContent()){
std::list<EydLib::BitGroup> uncompressedData = uncompressor.flush();
std::list<EydLib::BitGroup>::iterator uncmpDataIt;
for(uncmpDataIt = uncompressedData.begin();
uncmpDataIt != uncompressedData.end();
uncmpDataIt++){
bitwrite.write((*uncmpDataIt)); // cellule
}
}
record.push_back(bg);
//bitwrite.write(bg);
} catch (EydLib::eBitReaderEndOfFile& e) {
done = true;
// TODO: on flushe le contenu de record
// on flushe le contenu de record
uncompressor.flushRleData();
std::list<EydLib::BitGroup> uncompressedData = uncompressor.flush();
} catch (std::exception& e){
printf("ERROR\n");
}
}
printf("compression done\n");
printf("uncompression done\n");
bitread.close();
bitwrite.close();