Zlib是一种免费且通用的压缩库,由于Zlib压缩效果比LZW好,而且解压缩速度快,更重要的是商业软件中使用Zlib不需要缴纳版权费,所以很多游戏都使用Zlib压缩资源文件。
Zlib是由Jean-loup Gailly 和 Mark Adler共同编写完成的压缩库,Zlib是开源的,而且从Zlib的官方网站http://www.zlib.net/上可以下载到不同平台和编译器下的源代码实现。
Zlib联合使用LZ77算法和Huffman哈夫曼树来实现数据压缩和数据解压。
zlib源码http://download.csdn.net/detail/huangyuancao/7760901
void MainWindow::on_pushButton_clicked()
{
FILE* File_src;
FILE* File_compress;
FILE* File_uncompress;
unsigned long len_src;
unsigned long len_compress;
unsigned long len_uncompress = MaxBufferSize;
unsigned char *buffer_src = new unsigned char[MaxBufferSize];
unsigned char *buffer_compress = new unsigned char[MaxBufferSize];
unsigned char *buffer_uncompress = new unsigned char[MaxBufferSize];
File_src = fopen("src.txt","r");
File_compress = fopen("compress.txt","w");
File_uncompress = fopen("uncompress.txt","w");
//compress
len_src = fread(buffer_src,sizeof(char),MaxBufferSize-,File_src);
compress(buffer_compress,&len_compress,buffer_src,len_src);
fwrite(buffer_compress,sizeof(char),len_compress,File_compress);
qDebug() << "normal zlib:" ;
qDebug() << "src:\n" << buffer_src << ",length:" << len_src ;
qDebug() << "compress:\n" << buffer_compress << ",length:" << len_compress ;
//uncompress
uncompress(buffer_uncompress,&len_uncompress,buffer_compress,len_compress);
fwrite(buffer_uncompress,sizeof(char),len_uncompress,File_uncompress);
qDebug() << "uncompress:\n" << buffer_uncompress << ",length:" << len_uncompress;
fclose(File_src);
fclose(File_compress);
fclose(File_uncompress);
}
void MainWindow::on_pushButton_2_clicked()
{
QByteArray src;
src.append("*,china mobile,123456 ");
unsigned long len_compress;
unsigned long len_uncompress;
unsigned char *buffer_compress = new unsigned char[MaxBufferSize];
unsigned char *buffer_uncompress = new unsigned char[MaxBufferSize];
compress(buffer_compress,&len_compress,(Bytef*)src.data(), src.length());
uncompress(buffer_uncompress,&len_uncompress,buffer_compress,len_compress);
qDebug() << "qt zlib:" ;
qDebug() << "src:\n" << src.data() << ",length:" << src.size() ;
qDebug() << "compress:\n" << buffer_compress << ",length:" << len_compress ;
qDebug() << "uncompress:\n" << buffer_uncompress << ",length:" << len_uncompress ;
}
执行效果:
参考http://www.cnblogs.com/chuncn/archive/2011/03/23/1992481.html
qt调用zlib实例http://download.csdn.net/detail/huangyuancao/7760919