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Developping with aubio
Here is a brief overview of the C library.
For a more detailed list of available functions, see the API documentation.
To report issues, ask questions, and request new features, use Github Issues
Design Basics
The library is written in C and is optimised for speed and portability.
The C API is designed in the following way:
// new_ to create an object foobar aubio_foobar_t * new_aubio_foobar(void * args); // del_ to delete foobar void del_aubio_something (aubio_something_t * t); // _do to process output = foobar(input) audio_something_do (aubio_something_t * t, fvec_t * input, cvec_t * output); // _get_param to get foobar.param smpl_t aubio_something_get_a_parameter (aubio_something_t * t); // _set_param to set foobar.param uint_t aubio_something_set_a_parameter (aubio_something_t * t, smpl_t a_parameter);
For performance and real-time operation, no memory allocation or freeing take place in the _do methods. Instead, memory allocation should always take place in the new_ methods, whereas free operations are done in the del_ methods.
Vectors and matrix
fvec_t are used to hold vectors of float (smpl_t).
.. literalinclude:: ../tests/src/test-fvec.c :language: C :lines: 7
// set some elements vec->data[511] = 2.; vec->data[vec->length-2] = 1.;
Similarly, fmat_t are used to hold matrix of floats.
.. literalinclude:: ../tests/src/test-fmat.c :language: C :lines: 9-19
Reading a sound file
In this example, aubio_source is used to read a media file.
First, create the objects we need.
.. literalinclude:: ../tests/src/io/test-source.c :language: C :lines: 22-24, 30-32, 34
Note
With samplerate = 0, aubio_source will be created with the file's original samplerate.
Now for the processing loop:
.. literalinclude:: ../tests/src/io/test-source.c :language: C :lines: 40-44
At the end of the processing loop, clean-up and de-allocate memory:
.. literalinclude:: ../tests/src/io/test-source.c :language: C :lines: 50-56
See the complete example: :download:`test-source.c <../tests/src/io/test-source.c>`.
Computing a spectrum
Now let's create a phase vocoder:
.. literalinclude:: ../tests/src/spectral/test-phasevoc.c :language: C :lines: 6-11
The processing loop could now look like:
.. literalinclude:: ../tests/src/spectral/test-phasevoc.c :language: C :lines: 21-35
See the complete example: :download:`test-phasevoc.c <../tests/src/spectral/test-phasevoc.c>`.
Doxygen documentation
The latest version of the API documentation is built using Doxygen and is available at:
https://aubio.org/doc/latest/
Contribute
Please report any issue and feature request at the Github issue tracker. Patches and pull-requests welcome!
