hi
Checking with h5dump yielded these results. So the compression is indeed active
and the dataspace size is the same but not the storage layout size.I get a lot
larger storage size with the compression.
Do you have any clue as to how to set dynamically the chunk size to avoid
this issue ? ( i'm supposing it comes from our chunk size of course .. maybe
i'm wrong).
Gabriel
DATASET "bnd_tri->elem" {
DATATYPE H5T_STD_I32LE
DATASPACE SIMPLE { ( 1706886 ) / ( 1706886 ) }
STORAGE_LAYOUT {
CHUNKED ( 682754 )
SIZE 8193048 (0.833:1 COMPRESSION)
}
FILTERS {
COMPRESSION DEFLATE { LEVEL 6 }
}
FILLVALUE {
FILL_TIME H5D_FILL_TIME_IFSET
VALUE 0
}
ALLOCATION_TIME {
H5D_ALLOC_TIME_INCR
}
}
DATASET "bnd_tri->elem" {
DATATYPE H5T_STD_I32LE
DATASPACE SIMPLE { ( 1706886 ) / ( 1706886 ) }
STORAGE_LAYOUT {
CONTIGUOUS
SIZE 6827544
OFFSET 122165496
}
FILTERS {
NONE
}
FILLVALUE {
FILL_TIME H5D_FILL_TIME_IFSET
VALUE 0
}
ALLOCATION_TIME {
H5D_ALLOC_TIME_LATE
}
________________________________
De : Alligator <[email protected]>
À : "[email protected]" <[email protected]>
Envoyé le : Mercredi 6 juin 2012 22h25
Objet : [Hdf-forum] HDF GZ compression increases file size ??
Hi i'm using hdf 1.8.2
I've been playing with the standard GZ filter to compress my files and
when treating some files i found out it actually increased the file size ! Has
anyone else seen this ? even level 1 comrpession or level 6
compression yield the same file size and an increase of almost 50% in file
size. Is it possible that chunk size is responsible of this ? Is there an
intelligent way to set this parameter then ? thanks a lot for any help you
might provide
Pablo
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Hdf-forum is for HDF software users discussion.
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Hdf-forum is for HDF software users discussion.
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http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
