Extracting dataset from HDF5 table with GZIP compression

HDF5 Library C++ Users' Group
1

Hello all,

I have this kind of properties for my dataset that I wanted to extract:
image

As the image attached, the dataset is being compressed with GZIP filters (level 6). I try to find some documentation of compressing the dataset using filters but did not find any on extracting the value from the dataset. Any documentation on the filters and compression or example on decompressing the dataset using the Cpp is welcomed.

2

(Did you know that you can export directly from HDFView?)

I think the easiest way on offer (for C++) would be to use the HDFql C++ bindings and a query like this:

SELECT FROM "/Waveforms/Channel 1/Channel 1Data" INTO [file options] FILE target_file

See section 6.3.2 in the HDFql reference manual, which also has examples.

G.

1 Like
3

Good morning,
I have the same problem than @haziq.zur. I use the official HDF5 C++ API to read a gzipped compound dataset. The function read() of the DataSet object fails.
But when I generate a H5 file none zipped, the read works perfectly.
I don’t know why the API don’t unzip automatically the dataset. And I don’t see any parameters allowing to read a zipped dataset.
Any suggestion will be appreciated.
Of course, I want to keep using of C++ API.
Thanks you for help