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老外的超高效率压缩

      char</font></td>
    <td><font size="-1"><u>MByte</u><br>
      sec </font></td>
    <td><font size="-1">Opt</font></td>
    <td><font size="-1"><u>bits</u><br>
      char</font></td>
    <td><font size="-1"><u>MByte</u><br>
      sec </font></td>
  </tr>
  <tr> 
    <td align="center"><font color="#FF0000" size="-1"><b>1</b></font></td>
    <td align="right"><font color="#FF0000" size="-1"><b>3,818<br>
      </b></font></td>
    <td align="right"><font color="#FF0000" size="-1"><b><u>1,337</u> <br>
      </b></font></td>
    <td align="center"><font size="-1">1</font></td>
    <td align="right"><font size="-1">3,027<br>
      </font></td>
    <td align="right"><font size="-1">0,507<br>
      </font></td>
    <td align="center"><font size="-1">1</font></td>
    <td align="right"><font size="-1">2,301<br>
      </font></td>
    <td align="right"><font size="-1">0,187<br>
      </font></td>
    <td align="center"><font size="-1">2 2</font></td>
    <td align="right"><font size="-1">2,560<br>
      </font></td>
    <td align="right"><font size="-1">0,301 </font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">2</font></td>
    <td align="right"><font size="-1">3,780</font></td>
    <td align="right"><font size="-1">1,271</font></td>
    <td align="center"><font size="-1">2</font></td>
    <td align="right"><font size="-1">2,914</font></td>
    <td align="right"><font size="-1">0,464</font></td>
    <td align="center"><font size="-1">2</font></td>
    <td align="right"><font size="-1">2,211</font></td>
    <td align="right"><font size="-1">0,187</font></td>
    <td align="center"><font size="-1">3 3</font></td>
    <td align="right"><font size="-1">2,148</font></td>
    <td align="right"><font size="-1">0,250</font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">3</font></td>
    <td align="right"><font size="-1">3,635</font></td>
    <td align="right"><font size="-1">1,292</font></td>
    <td align="center"><font size="-1">3</font></td>
    <td align="right"><font size="-1">2,817</font></td>
    <td align="right"><font size="-1">0,371</font></td>
    <td align="center"><font size="-1">3</font></td>
    <td align="right"><font size="-1">2,171</font></td>
    <td align="right"><font size="-1">0,183</font></td>
    <td align="center"><font size="-1">4 4<b>*</b></font></td>
    <td align="right"><font size="-1">1,976</font></td>
    <td align="right"><font size="-1">0,214</font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">4<b>*</b></font></td>
    <td align="right"><font size="-1">3,523</font></td>
    <td align="right"><font size="-1">1,246</font></td>
    <td align="center"><font size="-1">4</font></td>
    <td align="right"><font size="-1">2,716</font></td>
    <td align="right"><font size="-1">0,345</font></td>
    <td align="center"><font size="-1">4</font></td>
    <td align="right"><font size="-1">2,134</font></td>
    <td align="right"><font size="-1">0,180</font></td>
    <td align="center"><font size="-1">6 5</font></td>
    <td align="right"><font size="-1">1,921</font></td>
    <td align="right"><font size="-1">0,181</font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">5</font></td>
    <td align="right"><font size="-1">3,394</font></td>
    <td align="right"><font size="-1">1,218</font></td>
    <td align="center"><font size="-1">5</font></td>
    <td align="right"><font size="-1">2,637</font></td>
    <td align="right"><font size="-1">0,252</font></td>
    <td align="center"><font size="-1">5<b>*</b></font></td>
    <td align="right"><font size="-1">2,131</font></td>
    <td align="right"><font size="-1">0,179</font></td>
    <td align="center"><font size="-1">8 6</font></td>
    <td align="right"><font size="-1">1,906</font></td>
    <td align="right"><font size="-1">0,158</font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">6</font></td>
    <td align="right"><font size="-1">3,321</font></td>
    <td align="right"><font size="-1">1,167</font></td>
    <td align="center"><font size="-1">6<b>*</b></font></td>
    <td align="right"><font size="-1">2,600</font></td>
    <td align="right"><font size="-1">0,179</font></td>
    <td align="center"><font size="-1">6</font></td>
    <td align="right"><font size="-1">2,119</font></td>
    <td align="right"><font size="-1">0,177</font></td>
    <td align="center"><font size="-1">16 7</font></td>
    <td align="right"><font size="-1">1,902</font></td>
    <td align="right"><font size="-1">0,131</font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">7</font></td>
    <td align="right"><font size="-1">3,266</font></td>
    <td align="right"><font size="-1">1,020</font></td>
    <td align="center"><font size="-1">7</font></td>
    <td align="right"><font size="-1">2,592</font></td>
    <td align="right"><font size="-1">0,155</font></td>
    <td align="center"><font size="-1">7</font></td>
    <td align="right"><font size="-1">2,105</font></td>
    <td align="right"><font size="-1">0,178</font></td>
    <td align="center"><font size="-1"><b><font color="#FF0000">32 8</font></b></font></td>
    <td align="right"><font size="-1"><b><font color="#FF0000"><u>1,900</u></font></b></font></td>
    <td align="right"><font size="-1"><b><font color="#FF0000">0,121</font></b></font></td>
  </tr>
  <tr> 
    <td align="center"><font size="-1">8</font></td>
    <td align="right"><font size="-1">3,263</font></td>
    <td align="right"><font size="-1">0,909</font></td>
    <td align="center"><font size="-1">8</font></td>
    <td align="right"><font size="-1">2,583</font></td>
    <td align="right"><font size="-1">0,121</font></td>
    <td align="center"><font size="-1">8</font></td>
    <td align="right"><font size="-1">2,090</font></td>
    <td align="right"><font size="-1">0,175</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
  </tr>
  <tr> 
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td align="center"><font size="-1">9</font></td>
    <td align="right"><font size="-1">2,581</font></td>
    <td align="right"><font size="-1">0,093</font></td>
    <td align="center"><font size="-1">9</font></td>
    <td align="right"><font size="-1">2,090</font></td>
    <td align="right"><font size="-1">0,175</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
    <td><font size="-1">&nbsp;</font></td>
  </tr>
</table>
<b><font size="-1">*</font></b><font size="-1">) options by default <br>
</font>
<p align="left">For compare with existing archiver note that PKWARE PKZIP 2.5 
  this file set compress with 2.6 bits per char.</p>
<p align="left">The next table describing options for each algorithm</p>
<table width="100%" border="1" cellspacing="0" cellpadding="3" align="center">
  <tr align="center"> 
    <td> 
      <div align="center"><b>Method</b></div>
    </td>
    <td> 
      <div align="center"><b>Valid Options</b></div>
    </td>
  </tr>
  <tr> 
    <td width="20%" valign="top">Rank</td>
    <td>1..8. set compression level</td>
  </tr>
  <tr> 
    <td width="20%" valign="top">ZIP</td>
    <td>1..9. set compression level</td>
  </tr>
  <tr> 
    <td width="20%" valign="top">BZIP</td>
    <td>none</td>
  </tr>
  <tr> 
    <td width="20%" valign="top">PPM</td>
    <td>M O, where M is the memory limith in Mbyte and O is the prediction order 
      (delimited with space)</td>
  </tr>
</table>
<p>For more convenient operation you can use the stream interface (for more detail 
  see PowerArc.pas)</p>
<blockquote> 
  <p><font face="Courier New, Courier, mono" size="-1"><b>type</b> <br>
    &nbsp;&nbsp;TPowerArcCompressStream = <b>class</b>(TStream)<br>
    &nbsp;&nbsp;<b>public</b><br>
    &nbsp;&nbsp;&nbsp;&nbsp;<b>constructor</b> Create(BaseStream: TStream; FArcIdx: 
    integer;<br>
    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<b>const</b> FArcOpt: <b>string</b> = 
    '');<br>
    &nbsp;&nbsp;&nbsp;&nbsp;<b>destructor</b> Destroy; <b>override</b>;<br>
    &nbsp;&nbsp;<b>end</b>;</font></p>
  <p><font face="Courier New, Courier, mono" size="-1"> &nbsp;&nbsp;TPowerArcDecompressStream 
    = <b>class</b>(TStream)<br>
    &nbsp;&nbsp;<b>public</b><br>
    &nbsp;&nbsp;&nbsp;&nbsp;<b>constructor</b> Create(BaseStream: TStream);<br>
    &nbsp;&nbsp;&nbsp;&nbsp;<b>destructor</b> Destroy; <b>override</b>;<br>
    &nbsp;&nbsp;<b>end</b>; </font></p>
  </blockquote>
<hr>
<p align="center"> <font size="-1">Copyright &copy; 2001, <a href="http://www.softcomplete.com">SoftLab 
  MIL-TEC Ltd</a> </font></p>
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