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Retrieves information about a filter.
herr_t H5Zget_filter_info( H5Z_filter_t filter, unsigned int *filter_config )
SUBROUTINE h5zget_filter_info_f(filter, config_flags, hdferr) IMPLICIT NONE INTEGER, INTENT(IN) :: filter ! Filter, may be one of the ! following: ! H5Z_FILTER_DEFLATE_F ! H5Z_FILTER_SHUFFLE_F ! H5Z_FILTER_FLETCHER32_F ! H5Z_FILTER_SZIP_F INTEGER, INTENT(OUT) :: config_flags ! Bit field indicating whether ! a filter's encoder and/or ! decoder are available INTEGER, INTENT(OUT) :: hdferr ! Error code END SUBROUTINE h5zfilter_avail_f
|H5Z_filter_t ||IN: Identifier of the filter to query. See the introduction to this section of the reference manual for a list of valid filter identifiers.|
|unsigned int *|
OUT: A bit field encoding the returned filter information
H5Zget_filter_info retrieves information about a filter. At present, this means that the function retrieves a filter's configuration flags, indicating whether the filter is configured to decode data, to encode data, neither, or both.
filter_config is not set to NULL prior to the function call, the returned parameter contains a bit field specifying the available filter configuration. The configuration flag values can then be determined through a series of bitwise AND operations, as described below.
Valid filter configuration flags include the following:
|Encoding is enabled for this filter. |
|Decoding is enabled for this filter. |
|(These flags are defined for C in the HDF5 Library source code file |
A bitwise AND of the returned
filter_config and a valid filter configuration flag will reveal whether the related configuration option is available. For example, if the value of
H5Z_FILTER_CONFIG_ENCODE_ENABLED & filter_config
is true, i.e., greater than
0 (zero), the queried filter is configured to encode data; if the value is
FALSE, i.e., equal to
0 (zero), the filter is not so configured.
If a filter is not encode-enabled, the corresponding
H5Pset_* function will return an error if the filter is added to a dataset creation property list (which is required if the filter is to be used to encode that dataset). For example, if the
H5Z_FILTER_CONFIG_ENCODE_ENABLED flag is not returned for the SZIP filter,
H5Z_FILTER_SZIP, a call to
H5Pset_szip will fail.
If a filter is not decode-enabled, the application will not be able to read an existing file encoded with that filter.
This function should be called, and the returned
filter_config analyzed, before calling any other function, such as
H5Pset_szip, that might require a particular filter configuration.
Returns a non-negative value on success, a negative value on failure.
|1.6.3||Function introduced in this release.|
Fortran subroutine introduced in this release.