H4toH5 Conversion Library User's Guide

The document titled "H4toH5 Conversion Library User's Guide" is a comprehensive guide for users and developers who need to convert HDF4 data files to the HDF5 format using the H4toH5 Conversion Library. This guide provides detailed instructions on effectively utilizing the H4toH5 library and its associated tools.

Key parts of the document:

1. Introduction:

   • The guide begins by introducing the two primary tools available for conversion: the h4toh5 utility and the H4toH5 Conversion Library.
   • It outlines the types of HDF4 objects that can be converted to HDF5, such as SDSs, images, Vdatas, Vgroups, palettes, and annotations.

2. The H4toH5 Utility vs. the H4toH5 Library:

   • This section compares the h4toh5 utility, which performs a default conversion of entire HDF4 files, with the H4toH5 Library, which allows for more granular and customized conversions on an object-by-object basis.

3. Programming Model:

   • The guide provides a step-by-step overview of the programming model for using the H4toH5 Library, including initializing the library, opening HDF4 files and objects, performing conversions, and properly closing files and terminating library access.

4. Compiling:

   • Instructions for compiling programs that use the H4toH5 library are provided, including details on required header files and linking with the appropriate libraries.

5. Error Handling:

   • A simple error-handling mechanism is described, including retrieving error messages and understanding the types of errors that might occur during the conversion process.

6. Limitations:

   • The guide discusses several limitations of the H4toH5 Library, such as limited correctness checking, no recovery options, limited conversion options, and specific cases where certain HDF4 objects or features may not be converted.

7. References:

   • A list of references is provided for further reading and a deeper understanding of the conversion process, including the "Mapping HDF4 Objects to HDF5 Objects" specification.

8. Appendix:

   • The appendix includes practical resources such as a sample Makefile and an example program demonstrating how to convert an HDF4 SDS object to an HDF5 dataset.
   • It also compares the output of converted objects in HDF5 with their original HDF4 counterparts, providing insights into what changes occur during conversion.

Purpose of the Document:

The "H4toH5 Conversion Library User's Guide" is intended to help users and developers understand how to effectively use the H4toH5 Conversion Library to migrate data from the HDF4 format to HDF5. It is a practical manual offering clear instructions, code examples, and guidance on handling common issues and limitations during the conversion process.