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POLZO compress char*
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  1. POLZO compress char*
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    copied!<p>I have installed LZO on my Ubuntu machine and I would like to use ti to compress a char* type string.</p> <p>In the example files I have found this code snippet (I have already edited it just a little for my application):</p> <pre><code> int r; lzo_bytep in; lzo_bytep out; lzo_voidp wrkmem; lzo_uint in_len; lzo_uint out_len; lzo_uint new_len; int strToCompressLen; // I have added this /* * Step 1: initialize the LZO library */ if (lzo_init() != LZO_E_OK) { cout &lt;&lt; "internal error - lzo_init() failed !!!" &lt;&lt; endl; cout &lt;&lt; "(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable '-DLZO_DEBUG' for diagnostics)" &lt;&lt; endl; //return 4; } // here I get the data I want to compress char* imageData = (char*)imageIn-&gt;getFrame(); /* * Step 2: allocate blocks and the work-memory */ strToCompressLen = strlen(imageData); in = (lzo_bytep) xmalloc(strToCompressLen); out = (lzo_bytep) xmalloc((strToCompressLen + strToCompressLen / 16 + 64 + 3)); wrkmem = (lzo_voidp) xmalloc(LZO1X_1_MEM_COMPRESS); if (in == NULL || out == NULL || wrkmem == NULL) { cout &lt;&lt; "out of memory" &lt;&lt; endl; //return 3; } /* * Step 3: prepare the input block that will get compressed. * We just fill it with zeros in this example program, * but you would use your real-world data here. */ in_len = strToCompressLen; lzo_memset(in,0,in_len); /* * Step 4: compress from 'in' to 'out' with LZO1X-1 */ r = lzo1x_1_compress(in,in_len,out,&amp;out_len,wrkmem); if (r != LZO_E_OK) { /* this should NEVER happen */ cout &lt;&lt; "internal error - compression failed: " &lt;&lt; r &lt;&lt; endl; //return 2; } /* check for an incompressible block */ if (out_len &gt;= in_len) { cout &lt;&lt; "This block contains incompressible data." &lt;&lt; endl; //return 0; } </code></pre> <p>But what it does is it just fill in zeros. I need to compress a char* variable.</p> <p>I guess I need to edit these lines:</p> <pre><code> in_len = strToCompressLen; lzo_memset(in,0,in_len); </code></pre> <p>I have the string I want to compress in this variable:</p> <pre><code> char* imageData = (char*)imageIn-&gt;getFrame(); </code></pre> <p>Do I need to cast it to some other type?</p> <p>The documentation to LZO is not very helpful (or maybe I just can't use it properly).</p>
 

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