H4H5TOOLS version 2.0 released in May 2008

1. Introduction

This document describes the H4H5TOOLS and contains information on 
the platforms tested and limitations. H4H5TOOLS include three products, 
H4toH5 conversion library, H4toH5 conversion utility and H5toH4 
conversion utility.

Both H4toH5 conversion library and H4toH5 conversion utility follow HDF4 to 
HDF5 mapping document.  This document can be found at:
http://hdfgroup.com/HDF5/doc/ADGuide/H4toH5Mapping.pdf

The H4toH5 conversion library user's guide and reference manual can be 
found at:
http://hdfgroup.com/h4toh5/h4toh5lib_UG.pdf
http://hdfgroup.com/h4toh5/h4toh5lib_RM.pdf

If you have any questions or comments, please send them to:
help@hdfgroup.org


2. Platforms Tested

H4H5TOOLS have been tested on the following platforms and compilers:
   GNU/Linux(x86), gcc 3.4.6
   GNU/Linux(x86_64),gcc 4.1.2
   SGI Altix, Intel C Compiler 10.0.026 (IA-64)
   SunOS 5.10, cc 5.8
   Microsoft Windows xp, Visual Studio 2005 (x86)

3. Prerequisites

1) HDF4 (version 4.2r3) and supported libraries 
2) HDF5 (version 1.8.1 or higher) library
3) The absolute path of HDF5 library is in LD_LIBRARY_PATH
4) The absolute path of SZIP library is in LD_LIBRARY_PATH (optional)

4. Install  

Unix install: see INSTALL_Unix.txt
Windows XP install: see INSTALL_Windows.txt 
(see h4h5proj.zip in the windows directory )

5. New features
 1) HDF-EOS2 conversion (--with-hdfeos2 option)
   a) If H4H5TOOLS is configured with --with-hdfeos2 option, h4toh5 conversion utility
      will recognize HDF-EOS2 files and handle these files by using both HDF4
      APIs and HDF-EOS2 APIs. Three command line options (-eos -nc4 -nc4strict) were added.
   b) If converting an HDF-EOS2 file, h4toh5 conversion tool can generate HDF5 files that can be read by netCDF4.
       --- C. Lee May 23rd, 2008

 2) Windows development
   a) We use environment variables to represent HDF4 libraries 
      and external libraries. In this way, users can change their own HDF4 and external
      libraries easily.
   b) Only DLL versions of szip and zlib libraries are used.
      Please read the details at INSTALLh425_Windows.txt inside h4h5proj.zip.

      --- K. Yang  2005
 3) Handling of external libraries
    Since zlib and jpeg libraries are required for HDF4, so to use H4toH5
    library, zlib and jpeg are required. szip can be optional. To avoid using
    szip, users must build HDF4 and HDF5 with szip disabled, H4toH5 library
    then should be built with the new HDF4 and HDF5. 

     --- K. Yang  2005
 

6. Limitations and known problems
 1) When HDF-EOS2 is being handled,
   a) To make the output HDF5 file readable by netCDF4 API, the original
      structure of HDF-EOS2 is not always kept. h4toh5 may move some datasets to a
      sibling group. Also, it may introduce a hard link that didn't exist in the
      original file.
   b) Some HDFEOS2-specific data structures such as dimension maps are not converted
      because they are not HDF4 objects.

   --- C. Lee May 23rd, 2008

 2) In this release, all HDF5 property list parameters are set as H5P_DEFAULT. 
   --- K. Yang 2005
 3) Windows DLL versions of conversion tools may not work.
   --- K. Yang 2005

