1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
2<html>
3
4<head>
5<META http-equiv="Content-Type" content="text/html; charset=windows-1252">
6<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 8.0.0.0 for Windows">
7<META http-equiv="Content-Style-Type" content="text/css">
8<title>MI_FilterDiff*</title>
9<LINK rel="stylesheet" href="../../css/nitro.css" type="text/css">
10</head>
11
12<body>
13
14<h1 align="left">MI_FilterDiff* <IMG src="../../image/NTR.gif" width="23" height="12" border="0" align="middle"><IMG src="../../image/TWL.gif" width="23" height="12" border="0" align="middle"></h1>
15<h2>Syntax</h2>
16
17<dl>
18  <dd>
19<CODE>#include &lt;nitro/mi.h&gt;</CODE><BR>
20  <BR>
21  <CODE>void MI_FilterDiff8( const void *srcp, void *destp, u32 size, BOOL bitsize );</CODE><br>
22  <CODE>void MI_FilterDiff16( const void *srcp, void *destp, u32 size, BOOL bitsize );</CODE><br>
23  <CODE>void MI_FilterDiff32( const void *srcp, void *destp, u32 size, BOOL bitsize );</CODE></dd>
24</dl>
25<h2>Arguments</h2>
26<TABLE border="1" width="100%">
27  <TBODY>
28    <TR>
29      <TD width="13%"><EM><STRONG>srcp</STRONG></EM></TD>
30      <TD width="87%">The source address where difference filtered-data is stored.</TD>
31    </TR>
32    <TR>
33      <TD width="13%"><EM><STRONG>destp</STRONG></EM></TD>
34      <TD width="87%">The destination address where the data is expanded. Can be the same region as the source address.</TD>
35    </TR>
36    <TR>
37      <TD width="13%"><EM><STRONG>size</STRONG></EM></TD>
38      <TD width="87%">Size of the source address. It is expressed in bytes.</TD>
39    </TR>
40    <TR>
41      <TD width="13%"><EM><STRONG>bitsize</STRONG></EM></TD>
42      <TD width="87%">Bit depth of the difference filter. 16-bit if TRUE; 8-bit if FALSE.</TD>
43    </TR>
44  </TBODY>
45</TABLE>
46
47<h2>Return Values</h2>
48<p>None.</p>
49
50<H2>Description</H2>
51<P>Encodes data using a difference filter, then writes it to a specified memory region. The source address must be aligned to a 4-byte boundary. When the size of the compressed data is not a multiple of 4, adjust by padding it with zeros. The pointers to the source and destination addresses may point to the same region.</P>
52<P><CODE>MI_FilterDiff8()</CODE> writes in 8-bit units. On NITRO, you cannot decompress directly to VRAM.<BR><BR><BR> <CODE>MI_FilterDiff16()</CODE> writes in 16-bit units. It is also possible to decompress to DTCM or VRAM.<BR><BR><BR> <CODE>MI_FilterDiff32()</CODE> writes in 32-bit units. It operates at a higher speed than both <CODE>MI_FilterDiff8()</CODE> and <CODE>MI_FilterDiff16()</CODE>. It is also possible to decompress to DTCM or VRAM.</P>
53<h2>Internal Operation</h2>
54<P>Processing only takes place on the CPU, without the use of a system call or DMA.</P>
55<h2>See Also</h2>
56<p>
57<CODE><A href="MI_UnfilterDiff.html">MI_UnfilterDiff</A>, <A href="MI_CompressRL.html">MI_CompressRL</A>, <A href="MI_CompressHuffman.html">MI_CompressHuffman</A></CODE></p>
58
59<H2>Revision History</H2>
60<P>
612008/07/02 Initial version.
62</P>
63<hr><p>CONFIDENTIAL</p></body>
64</html>
65