2016-10-31 22:50 GMT+01:00 Peter Lindstrom <[email protected]>:
> My bad--I saw the table of six integers in README_MORE and assumed those
> were the six integers in PARAMS.  I should have kept reading...
>
> Still, looking at the integer parameters there appear to be some
> unintentional byte swapping issues.  The first four bytes should be 'z',
> 'f', 'p', \005, and these bytes show up in the second (32-bit) integer
> parameter (91252346 = 0x0570667a = ((\005 << 24) + ('p' << 16) + ('f' << 8)
> + ('z' << 0))).

I see now that the first entry (5242928 = 0x00500030) is the version
of ZFP / H5Z-ZFP (0.5.0 / 0.3.0), the filter encodes the ZFP header
from entry 1 and forward.

Elvis

>
> Mark and I will work to track down the issue.  Elvis, can you confirm that
> you compiled zfp with -DBIT_STREAM_WORD_TYPE=uint8?  See the zfp FAQ and
> H5Z-ZFP/README_MORE for more information on this.
>
>
> On 10/31/16 11:18, Miller, Mark C. wrote:
>
> Hi Elvis,
>
> The PARAMS dumped from the dataset header are *not* the same cd_values
> passed in memory between caller and plugin.
>
> The dataset header in the file gets something different; ZFP's header
> including mode and metadata + H5Z-ZFP plugin version info
>
> The README_MORE file in plugin on github explains this.
>
> Long story short, you can't deduce much from those values dumped by
> h5dump/h5ls, etc. You'd have to reverse engineer how
> ZFP library encodes magic, version, mode and metadata into its header.
>
> Mark
>
>
>
> --
> Mark C. Miller, LLNL
>
> From: Hdf-forum <[email protected]> on behalf of Peter
> Lindstrom <[email protected]>
> Reply-To: HDF Users Discussion List <[email protected]>
> Date: Monday, October 31, 2016 at 11:03 AM
> To: HDF Users Discussion List <[email protected]>
> Subject: Re: [Hdf-forum] New HDF5 compression plugin
>
> Elvis,
>
> Your compression parameters look suspicious to me:
>
> PARAMS { 5242928 91252346 313532218 -1043792 -937099264 67112167 }
>
> I would start by debugging those.  If I understand Mark's filter correctly,
> the first integer should be 1, 2, 3, or 4.
>
> On 10/31/16 09:55, Elvis Stansvik wrote:
>
> Den 31 okt. 2016 5:41 em skrev "Miller, Mark C." <[email protected]>:
>>
>> Hi Elvis,
>>
>>>
>>> I've successfully tried using the plugin through h5py. I did have a
>>> problem with the fixed-accuracy mode however and filed an issue:
>>>
>>>     https://github.com/LLNL/H5Z-ZFP/issues/1
>>>
>>> It's very likely that I'm doing something wrong though.
>>
>>
>> Thanks so much!!
>>
>> I will take a look at the issue you reported later this week.
>>
>> I may have to rope the researcher who developed ZFP in to help.
>>
>> AFAICT, I am calling ZFP with correct parameters and, your email confirms
>> you see zfp_stream_set_accuracy() being called.
>
> Alright, no hurry.
>
> I've been in contact with Peter earlier with some other questions. He seems
> very helpful.
>
> And yes, zfp_stream_set_accuracy seems to be called correctly with the
> parameters I pass through h5py (same as when I do the equivalent with the
> zfp command line tool), so I think something else is going on. The dataset
> type class and dimensions are also correctly identified by the filter
> plugin.
>
> Elvis
>
>>
>> Mark
>>
>>
>> _______________________________________________
>> Hdf-forum is for HDF software users discussion.
>> [email protected]
>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
>> Twitter: https://twitter.com/hdf5
>
>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> [email protected]http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> Twitter: https://twitter.com/hdf5
>
>
>
> --
> Peter Lindstrom . [email protected] . http://people.llnl.gov/pl . 925-423-5925
>
>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> [email protected]
> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> Twitter: https://twitter.com/hdf5
>
>
>
> --
> Peter Lindstrom . [email protected] . http://people.llnl.gov/pl . 925-423-5925
>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> [email protected]
> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org
> Twitter: https://twitter.com/hdf5

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