How to create OpenDAFF content

To create files that comply with the OpenDAFF format, you can use Matlab. Assemble your data sets, define your metadata and export the content to a single '*.daff' file. You can use various content types and as many channels as you wish. In the source code you will find a folder named 'matlab' which contains scripts to generate and write DAFF files. You can also access DAFF content from within Matlab. Use the DAFF Matlab executable, which is a bind interface to the C++ library. Follow the compile instructions for the DAFF Matlab Executable (mex) that can be found in the source repository at Sourceforge.

Convert existing HRTFs

Until this point, a number of free data sets are available that describe the directivity pattern of the human head and torso with high resolution in order to maintain acoustic cues that can be used for Binaural Technology, so called HRTFs in frequency domain or HRIRs in time domain.
Here is a list of data sets (without claiming completeness)

To convert those file collections into DAFF, have a look into the DAFF Matlab script repository mentioned above. If no native writer script is available, checkout the ITA-Toolbox for Matlab which provides ways to read various content (also including SOFA format for HRIR representation) and exports to DAFF format. If you are planning to convert an HRTF data set it is most likely that you will have to think about a way to map the (usually arbitrary) directions to a regular grid on a sphere. This is commonly done by finding the nearest neighbouring set, or by appropriate interpolation of the underlying directional data. Because this problem is not trivial, OpenDAFF cannot provide a general approach, here.

Converting Your Work

In the source code of the OpenDAFF project, you will find example scripts that can generate DAFF files based on different mathematical functions. Use them to generate for instance a figure of eight for a microphone directivity. The current version of these generated files can be downloaded from the files section under Content/Generated of the Sorceforge project page.
If you have your own directional data, say from a transfer path measurement, you need to write a data function that delivers content to the DAFF Matlab writer function. This data function is called during the export of a DAFF file for every required direction, and requests the corresponding data you want to connect. Find examples in the abovementioned script folder.