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[svn-r7125]

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Purpose:
    H5Pset_shuffle -- Add note regarding intended use.
    H5Pset_szip -- Correct options mask list.  Copy edits.

Description:
    H5Pset_shuffle -- Added note that the shuffle filter is designed to be
        used with in combination a compression filter.
    H5Pset_szip -- Changed 'szip' to 'SZIP' in running text.
        Removed RAW_OPTIONS_MASK, LSB_OPTIONS_MASK, and MSB-OPTIONS_MASK
            from options maks list as they are not available for user control.
        Added 'H5_SZIP_' prefix to all remaining option tags.
        Made corresponding changes to running text, removing or revising
            mentions of deleted option tags.

Platforms tested:
    IE 5
This commit is contained in:
Frank Baker
2003-06-30 13:52:18 -05:00
parent 3e297166b8
commit 82a89d2c18
1 changed files with 25 additions and 21 deletions
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46
doc/html/RM_H5P.html
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@@ -3922,6 +3922,9 @@ facilitate moving easily between them.</i>
algorithm because the bytes in each byte position are often
closely related to each other and putting them together
can increase the compression ratio.
<p>
This filter is designed to be used in combination with
a compression filter.
<dt><strong>Parameters:</strong>
<dl>
<dt><em>hid_t</em> <code>plist_id</code>
@@ -3979,13 +3982,13 @@ facilitate moving easily between them.</i>
<em>unsigned int</em> <code>options_mask</code>,
<em>unsigned int</em> <code>pixels_per_block</code>)
<dt><strong>Purpose:</strong>
<dd>Sets up use of the szip compression filter.
<dd>Sets up use of the SZIP compression filter.
<dt><strong>Description:</strong>
<dd><code>H5Pset_szip</code> sets a filter for the dataset
to szip compression, <code>H5Z_FILTER_SZIP</code>,
to SZIP compression, <code>H5Z_FILTER_SZIP</code>,
a compression method designed for use with scientific data.
<p>
Szip options are passed in an options mask, <code>options_mask</code>,
SZIP options are passed in an options mask, <code>options_mask</code>,
as follows.
<center>
<table>
@@ -4001,30 +4004,33 @@ facilitate moving easily between them.</i>
<tr valign=top align=left><td>
<hr>
<code>CHIP_OPTION_MASK&nbsp;&nbsp;</code>
<code>H5_SZIP_CHIP_OPTION_MASK&nbsp;&nbsp;</code>
</td><td>
<hr>
Compresses exactly as in hardware.
</td></tr>
<tr valign=top align=left><td>
<code>ALLOW_K13_OPTION_MASK&nbsp;&nbsp;</code>
<code>H5_SZIP_ALLOW_K13_OPTION_MASK&nbsp;&nbsp;</code>
</td><td>
Allows k split = 13 compression mode. (Default)
</td></tr>
<tr valign=top align=left><td>
<hr>
<code>EC_OPTION_MASK</code>
<code>H5_SZIP_EC_OPTION_MASK</code>
</td><td>
<hr>
Selects entropy coding method. (Default)
</td></tr>
<tr valign=top align=left><td>
<code>NN_OPTION_MASK</code>
<code>H5_SZIP_NN_OPTION_MASK</code>
</td><td>
Selects nearest neighbor coding method.
</td></tr>
<!-- THESE OPTIONS ARE SET DIRECTLY BY THE LIBRARY AND
ARE NOT AVAILABLE FOR USER CONTROL
<tr valign=top align=left><td>
<hr>
<code>LSB_OPTION_MASK</code>
@@ -4043,10 +4049,12 @@ facilitate moving easily between them.</i>
<code>RAW_OPTION_MASK</code>
</td><td>
<hr>
Do not output szip header.<br>
Do not output SZIP header.<br>
Not a default setting, but should always be set in HDF5.
</td></tr>
END LIBRARY-SET OPTION TAGS -->
<tr valign=top align=left><td>
<hr>
</td><td>
@@ -4056,24 +4064,20 @@ facilitate moving easily between them.</i>
</center>
Some typical usages are as follows:
<ul>
<li>If the dataset employs more than 8 bits/pixel,
one of <code>LSB_OPTION_MASK</code> or
<code>MSB_OPTION_MASK</code> is specified.
<li>One of the compression methods,
<code>EC_OPTION_MASK</code> or
<code>NN_OPTION_MASK</code>, is specified.
<li>The <code>RAW_OPTION_MASK</code> and
<code>ALLOW_K13_OPTION_MASK</code> are used.
<code>H5_SZIP_EC_OPTION_MASK</code> or
<code>H5_SZIP_NN_OPTION_MASK</code>, is specified.
<li>The <code>H5_SZIP_ALLOW_K13_OPTION_MASK</code> is used.
</ul>
<p>
Options are combined to create the options mask by means of
a logical <code>OR</code> operation. For example, the
option mask can be set as follows:
<br><br><code>&nbsp;&nbsp;&nbsp;&nbsp;
options_mask = MSB_OPTION_MASK | NN_OPTION_MASK | RAW_OPTION_MASK;
options_mask = H5_SZIP_NN_OPTION_MASK | H5_SZIP_ALLOW_K13_OPTION_MASK;
</code>
<p>
Szip compresses data block by block, with a user-tunable block size.
SZIP compresses data block by block, with a user-tunable block size.
This block size is passed in the parameter
<code>pixels_per_block</code> and must be even,
with typical values being <code>8</code>, <code>10</code>,
@@ -4084,10 +4088,10 @@ facilitate moving easily between them.</i>
should be an even multiple of the number of pixels per block.
<p>
<dt><strong>Notes:</strong>
<dd>Szip works only with datasets with 1 through 24 bits/pixel,
<dd>SZIP works only with datasets with 1 through 24 bits/pixel,
32 pits/pixel, or 64 bits/pixel.
<p>
Szip typically requires that the user application also supply
SZIP typically requires that the user application also supply
the number of pixels in the object to be compressed,
the number of bits per pixel, and the number of pixels per scan line.
These values need not be independently supplied in the HDF5
@@ -4099,7 +4103,7 @@ facilitate moving easily between them.</i>
<dd>IN: Dataset creation or dataset transfer property list
identifier.
<dt><em>unsigned int</em> <code>options_mask</code>
<dd>IN: A bit-mask conveying the desired szip options.
<dd>IN: A bit-mask conveying the desired SZIP options.
<dt><em>unsigned int</em> <code>pixels_per_block</code>
<dd>IN: The number of pixels or data elements in each data block.
</dl>
@@ -7633,7 +7637,7 @@ And in this document, the
Describes HDF5 Release 1.5, Unreleased Development Branch
</address><!-- #EndLibraryItem -->
Last modified: 25 June 2003
Last modified: 30 June 2003
</body>
</html>