H5Pset_deflate
(
hid_t plist_id
,
uint 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 propertly 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
(see
zlib
).
hid_t
plist_id
IN: Dataset or group creation
property list identifier.
uint
level
IN: Compression level.
SUBROUTINE h5pset_deflate_f(prp_id, level, hdferr)
IMPLICIT NONE
INTEGER(HID_T), INTENT(IN) :: prp_id ! Property list identifier
INTEGER, INTENT(IN) :: level ! Compression level
INTEGER, INTENT(OUT) :: hdferr ! Error code
! 0 on success and -1 on failure
END SUBROUTINE h5pset_deflate_f
Release
Change
1.8.5
Function extended to work with group creation property
lists.