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HDF5
1.13.0
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HDF5
1.13.0
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Functions | |
| H5Z_filter_t | H5Pget_filter2 (hid_t plist_id, unsigned filter, unsigned int *flags, size_t *cd_nelmts, unsigned cd_values[], size_t namelen, char name[], unsigned *filter_config) |
| Returns information about a filter in a pipeline. More... | |
| int | H5Pget_nfilters (hid_t plist_id) |
| Returns the number of filters in the pipeline. More... | |
| herr_t | H5Pset_deflate (hid_t plist_id, unsigned aggression) |
| Sets deflate (GNU gzip) compression method and compression level. More... | |
| H5Z_filter_t | H5Pget_filter1 (hid_t plist_id, unsigned filter, unsigned int *flags, size_t *cd_nelmts, unsigned cd_values[], size_t namelen, char name[]) |
| Returns information about a filter in a pipeline (DEPRECATED) More... | |
| H5Z_filter_t H5Pget_filter1 | ( | hid_t | plist_id, |
| unsigned | filter, | ||
| unsigned int * | flags, | ||
| size_t * | cd_nelmts, | ||
| unsigned | cd_values[], | ||
| size_t | namelen, | ||
| char | name[] | ||
| ) |
Returns information about a filter in a pipeline (DEPRECATED)
| [in] | plist_id | Property list identifier |
| [in] | idx | Sequence number within the filter pipeline of the filter for which information is sought |
| [out] | flags | Bit vector specifying certain general properties of the filter |
| [in,out] | cd_nelmts | Number of elements in cd_values |
| [out] | cd_values | Auxiliary data for the filter |
| [in] | namelen | Anticipated number of characters in name |
| [out] | name | Name of the filter |
H5Pget_filter1() returns information about a filter, specified by its filter number, in a filter pipeline, specified by the property list with which it is associated.
plist_id must be a dataset or group creation property list.
idx is a value between zero and N-1, as described in H5Pget_nfilters(). The function will return a negative value if the filter number is out of range.
The structure of the flags argument is discussed in H5Pset_filter().
On input, cd_nelmts indicates the number of entries in the cd_values array, as allocated by the caller; on return, cd_nelmts contains the number of values defined by the filter.
If name is a pointer to an array of at least namelen bytes, the filter name will be copied into that array. The name will be null terminated if namelen is large enough. The filter name returned will be the name appearing in the file, the name registered for the filter, or an empty string.
filter parameter type changed to unsigned.| H5Z_filter_t H5Pget_filter2 | ( | hid_t | plist_id, |
| unsigned | filter, | ||
| unsigned int * | flags, | ||
| size_t * | cd_nelmts, | ||
| unsigned | cd_values[], | ||
| size_t | namelen, | ||
| char | name[], | ||
| unsigned * | filter_config | ||
| ) |
Returns information about a filter in a pipeline.
| [in] | plist_id | Property list identifier |
| [in] | idx | Sequence number within the filter pipeline of the filter for which information is sought |
| [out] | flags | Bit vector specifying certain general properties of the filter |
| [in,out] | cd_nelmts | Number of elements in cd_values |
| [out] | cd_values | Auxiliary data for the filter |
| [in] | namelen | Anticipated number of characters in name |
| [out] | name | Name of the filter |
| [out] | filter_config | Bit field, as described in H5Zget_filter_info() |
H5Pget_filter2() returns information about a filter specified by its filter number, in a filter pipeline specified by the property list with which it is associated.
plist_id must be a dataset or group creation property list.
idx is a value between zero and N-1, as described in H5Pget_nfilters(). The function will return a negative value if the filter number is out of range.
The structure of the flags argument is discussed in H5Pset_filter().
On input, cd_nelmts indicates the number of entries in the cd_values array, as allocated by the caller; on return, cd_nelmts contains the number of values defined by the filter.
If name is a pointer to an array of at least namelen bytes, the filter name will be copied into that array. The name will be null terminated if namelen is large enough. The filter name returned will be the name appearing in the file, the name registered for the filter, or an empty string.
filter_config is the bit field described in H5Zget_filter_info().
| int H5Pget_nfilters | ( | hid_t | plist_id | ) |
Returns the number of filters in the pipeline.
| [in] | plist | Property list identifier |
H5Pget_nfilters() returns the number of filters defined in the filter pipeline associated with the property list plist.
In each pipeline, the filters are numbered from 0 through N-1, where N is the value returned by this function. During output to the file, the filters are applied in increasing order; during input from the file, they are applied in decreasing order.
H5Pget_nfilters() returns the number of filters in the pipeline, including zero (0) if there are none.
Sets deflate (GNU gzip) compression method and compression level.
| [in] | plist_id | Property list identifier |
| [in] | level | Compression level |
H5Pset_deflate() sets the deflate compression method and the compression level, level, for a dataset or group creation property list, plist_id.
The filter identifier set in the property list is H5Z_FILTER_DEFLATE.
The compression level, level, is a value from zero to nine, inclusive. A compression level of 0 (zero) indicates no compression; compression improves but speed slows progressively from levels 1 through 9:
| Compression Level | Gzip Action |
|---|---|
| 0 | No compression |
| 1 | Best compression speed; least compression |
| 2 through 8 | Compression improves; speed degrades |
| 9 | Best compression ratio; slowest speed |
Note that setting the compression level to 0 (zero) does not turn off use of the gzip filter; it simply sets the filter to perform no compression as it processes the data.
HDF5 relies on GNU gzip for this compression.
1.8.18