H5P_SET_DEFLATE sets the deflate compression method and the compression level,
level for a dataset or group creation property list,
The filter identifier set in the property list is
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|
|Best compression speed; least compression|
|Compression improves; speed degrades|
|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.