Welcome to Pd-Motion¶

Pd-motion (formely MbLib) is a set of abstractions for Pure Data that helps to manipulate the spatialisation of audio streams and handle head tracking data coming from a Flock of Bird.

This project has been developed within the Action and Perception group of the school of Psychology at Cardiff University. A new audiovisual lab has been created and needed a bit of code in order to be able to use properly the equipments. Pure Data has been chosen for several reasons:

able to drive an old Flock of Bird head tracker out of the box
Real time capacities
Run on Windows, GNU/Linux and MacOsX
Open source software

You’ll find several abstractions to manipulate and acquire data from the head tracker, basic filtering, spatialisation, a staircase method and so on. All the objects are supposed to be as generic as possible and should be usable outside of its main purpose in the lab.

Please, download it, study it, improve it and share it!

Installation¶

I invite you to use PdExtended rather than the vanilla version of Pure Data. For the compilation it won’t have any impact (as it uses the same library pdlib.h) but at least you’ll have all the integrated other libraries on which some abstractions are relying on.

Important note¶

At the moment the current makefile does not work properly and will be corrected really soon.

Compilation of the external¶

Linux¶

In order to compile and install this library you will need:

gcc >= 4.7.1
gnu-make >= 3.82
Pure Data >= 0.45

To compile the library:

make make install

All file will be added to you default Pure Data external folder ~/pdextended.

Windows¶

In order to compile under windows, you will need:

Mingw
Pure Data >= 0.45

To compile the library:

mingw32-make mingw32-make install

All files will be install for the current user in %%application_data%%

MacOs¶

The Makefile does’nt take into account MacOs compilation at the moment.

Installation of abstraction License ——-

Please refer to the LICENSE file at the root of the project.

Contributing¶

We’re really happy to accept contributions from the community, that’s the main reason why we open-sourced it! There are many ways to contribute, even if you’re not a technical person.

We’re using the infamous simplified Github workflow to accept modifications (even internally), basically you’ll have to:

create an issue related to the problem you want to fix (good for traceability and cross-reference)
fork the repository
create a branch (optionally with the reference to the issue in the name)
hack hack hack
commit incrementally with readable and detailed commit messages
submit a pull-request against the master branch of this repository

We’ll take care of tagging your issue with the appropriated labels and answer within a week (hopefully less!) to the problem you encounter.

If you’re not familiar with open-source workflows or our set of technologies, do not hesitate to ask for help! We can mentor you or propose good first bugs (as labeled in our issues). Also welcome to add your name to Credits section of this document.

Submitting bugs¶

You can report issues the issue tracker of the project, that would be a really useful contribution given that we lack some user testing on the project. Please document as much as possible the steps to reproduce your problem (even better with screenshots).

Abstraction and externals documentation¶

Abstractions¶

Audio¶

audio-stim: Generate audio stimulus properties.
bandpass~: Band-pass filter with a bypass option.
bandpass24~: 24 channels band-pass filter with a bypass option. (Requires bandpass~).
fadeio~: Fade in/out manager.
gaussian-gain: Compute the gain to apply to a speaker depending of the source size.
gaussian-spat24: Compute the gains to apply to a 24 channels sound system according to the position of the speakers and the source width. (Requires gaussian-gain).
master24~: 24 channels master with a fade in/out manager. (Requires fadeio).
motion24~: Spatialize an incoherent stimulus (noise for example) over 24 channels. (Requires gaussian-spat24).
mute24~: 24 audio channels mute.
noise24~: 24 audio channels of white noise. Each channel generate independent noise (useful to simulate source motion).
partconv-im~: 1 channel filtering object using partitionned convolution method. This object can be bypass. (Requires partconv~).
playfile~: Play any wave file in argument using a table method.
spectral-corr24~: 24 audio channels applying spectral filtering on input signals. This object can be bypass if necessary. (Requires partconv-im~).
stimulus-position: Generate the azimuth position stream according to several parameters.
vumeter~: GUI object displaying the level in dBfs (full scale) of an audio signal.

Head tracking (Flock of Bird)¶

bird-conv-ang: Conversion of an angular Flock of Bird raw data flow in azimuth, elevation and roll in degrees.
bird-conv-pos: Conversion of a position Flock of Bird raw data flow in x, y and z in inches or centimeters.
bird-ctl: Flock of Bird acquisition control features.
bird-raw-pos-ang: Flock of Bird raw flow extraction. Output two separate raw flows, one for position, one for angles.

Miscellaneous¶

cmp-gate: Comparative gate using 2 boundaries.
get-button: Send a unique bang when the right key is hit.
get-displacement: Get the displacement according to the duration and speed of an object.
in2cm: Convert inches in centimeters.
percentage: Compute a given percentage of a value.
pr-bit: Generate a pseudo random bit (0 or 1) and then alternate the value.
rand: A superior layer of random object. You just to specify a range of value from 0 and shift of this range.
serial-ctl: Superior layer to comport in order to open/close, specify a baud rate for the serial port.

Externals¶

staircase: Staircase method.