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Software Patches

Members of the HDF community are encouraged submit patches to HDF software for The HDF Group to consider including in an upcoming maintenance release.

The source code for HDF5 and our other software products are hosted on a local Bitbucket server:

To submit a patch for any of the software found on the Bitbucket server, please contact the Help Desk.

You will need to agree to a Contributor License Agreement before The HDF Group can include your code in a public release of our software.

Registered Third-Party Filters

Members of the HDF5 users community can register Third-Party (compression or other) filters for use with HDF5. (See the FAQ on Using Compression in HDF5 for how to add a Third-Party Filter to HDF5.)

To register a filter please contact The HDF Helpdesk with the following information: 

  • Contact information for the developer requesting a new identifier
  • Short description of the new filter
  • Links to any relevant information including licensing information 

Here is the current policy regarding filter identifier assignment:

The filter identifier is designed to be a unique identifier for the filter. Values from zero through 32,767 are reserved for filters supported by The HDF Group in the HDF5 library and for filters requested and supported by the 3rd party.

Values from 32768 to 65535 are reserved for non-distributed uses (e.g., internal company usage) or for application usage when testing a feature. The HDF Group does not track or document the usage of filters with identifiers from this range.


Please contact the maintainer of a filter for help with the filter/compression support in HDF5.

List of Filters Registered with The HDF Group
Filter Identifier
(click on the link for more information about the filter)
NameShort Description
305LZOLZO lossless compression used by PyTables
307BZIP2BZIP2 lossless compression used by PyTables
32000LZFLZF lossless compression used by H5Py project
32001BLOSCBlosc lossless compression used by PyTables
32002MAFISCModified LZMA compression filter, MAFISC (Multidimensional Adaptive Filtering Improved Scientific data Compression)
32003SnappySnappy lossless compression.
32004LZ4LZ4 fast lossless compression algorithm
32005APAXSamplify's APAX Numerical Encoding Technology
32006CBFAll imgCIF/CBF compressions and decompressions, including Canonical, Packed, Packed Vesrsion 2, Byte Offset and Nibble Offset.
32007JPEG-XREnables images to be compressed/decompressed with JPEG-XR compression
32008bitshuffleExtreme version of shuffle filter that shuffles data at bit level instead of byte level.
32009SPDPSPDP fast lossless compression algorithm for single- and double-precision floating-point data.
32010LPC-RiceLPC-Rice multi-threaded lossless compression
32011CCSDS-123ESA CCSDS-123 multi-threaded compression filter
32012JPEG-LSCharLS JPEG-LS multi-threaded compression filter
32013zfpRate, accuracy or precision bounded compression for floating-point arrays
32014fpzipFast and Efficient Lossy or Lossless Compressor for Floating-Point Data
32015ZstandardReal-time compression algorithm with wide range of compression / speed trade-off and fast decoder
32016B³DGPU based image compression method developed for light-microscopy applications
32017SZAn error-bounded lossy compressor for scientific floating-point data
32018FCIDECOMPEUMETSAT CharLS compression filter for use with netCDF
32019JPEGJpeg compression filter

Registered User-defined Link Classes

No user-defined link classes have been registered with The HDF Group at this time. For more information on how to register user-defined link classes, see the H5Lregister function in the HDF5 Reference Manual.

--- Last Modified: April 19, 2019 | 01:56 PM