# Applications Programming Interface

The publically callable functions of libsamplerate are all listed in the <samplerate.h> header file. In order to use any of the functionality of libsamplerate, you need to add

    	#include <samplerate.h>

to the top of any function that call any of the following functions. You will also need to link you binary with the libsamplerate library.

The API allows three methods for accessing the capabilies of the library:

- A simple interface which can sample rate convert a single block of samples (one or more channels) in one go. The simple API is less capable than the full API.
- A more fully featured interface which allows time varying sample rate conversion on streaming data (again one or more channels).
- A callback interface which has the same functionality as the interface above but allows the details of input and output to be separated. The output is generated by call a read function and the library calls a user supplied callback function to obtain its input. This interface is particularly well suited to applications where the output sample rate is varied with time.

NB : All three access methods are able to process multi channel interleaved data.

The parts of the API which are common to all three interfaces are:

- The error reporting mechanisim.
- The available converter types.
- The SRC_DATA struct.

All three versions of the API are restricted to operating on buffers of ISO C Standard float data. However, there are two auxillary functions for converting arrays of float data to and from short data.

Note: The tests/ and examples/ directories of the source code distribution contain numerous example programs showing the use of the library.