# Library for Acoustic Signal Processing

- Master branch: [![Build Status](https://drone.ascee.nl/api/badges/ASCEE/lasp/status.svg?ref=refs/heads/master)](https://drone.ascee.nl/ASCEE/lasp)
- Develop branch: [![Build Status](https://drone.ascee.nl/api/badges/ASCEE/lasp/status.svg?ref=refs/heads/develop)](https://drone.ascee.nl/ASCEE/lasp)


Welcome to LASP: Library for Acoustic Signal Processing. LASP is a C++ library
with a Python interface which is supposed to acquire and process (multi) sensor data in real time on a PC and output results.

Current features that are implemented:


- Communication with data acquisition (DAQ) devices, of which:
    - Internal sound cards via the [RtAudio](http://www.music.mcgill.ca/~gary/rtaudio) backend. Many thanks to Gary P. Scavone et al.
    - [Measurement Computing](https://www.mccdaq.com) [DT9838A](https://www.mccdaq.com/Products/Sound-Vibration-DAQ/DT9837) signal analyzer.
- Configuration of DAQ devices: AC coupling, IEPE, sensitivity physical
  quantities.
- Recording of signals from these DAQ devices, and storing in a HDF5 file.
- Filter designers to create A/C sound pressure weighting
- Biquad filter designers for low pass, high pass, peaking and notch filters
- A Peak Programme Meter (PPM) to monitor signal levels from DAQ and to watch
  for signal clipping.
- A signal generator to create sine waves, sweeps and noise (white / pink).
- Equalizers to equalize the output prior to sending.
- Averaged power spectra and power spectral density determination
  using Welch' method. Taper functions of Hann, Hamming, Bartlett and
  Blackman are provided.
- (One third) octave filter bank filters designed to comply with IEC 61260
  (1995).
- Slow and fast time updates of (A/C/Z) weighted sound pressure levels
- Full Sound Level Meter implementation
- Real time Sound Level meter, Power / Transfer function estimator
- Spectra data smoothing algorithms
- Sensor calibration for microphones


Future features (wish-list)


- Conventional and delay-and-sum beam-forming algorithms
- Impedance tube measurement processing

For now, the source code is well-documented on [lasp.ascee.nl](https://lasp.ascee.nl) but it requires some
additional documentation (the math behind it). This is maintained
in a sister repository [lasp-doc](https://code.ascee.nl/ascee/lasp-doc).

If you have any question(s), please feel free to contact us: [email](info@ascee.nl).

# Installation - Linux (Debian-based)

## Dependencies

- `$ sudo apt install python3-pybind11 libopenblas-dev python3-pip python3-scipy libusb-1.0-0-dev libpulse-dev cmake-curses-gui python3-h5py`
- `$ pip3 install --user -r requirements.txt`


If building RtAudio with the ALSA backend, you will also require the following packages:

- libclalsadrv-dev

If building RtAudio with the Jack Audio Connection Kit (JACK) backend, you will also require the following packages:

- libjack-jackd2-dev

## Download & build

- `$ git clone --recursive https://code.ascee.nl/ASCEE/lasp.git`
- `$ cd lasp`

For a release build:

- `$ cmake .`

or optionally for a custom build:

- `$ ccmake .`

Configure and run:

- `$ make -j`

### Build documentation

In directory:

`$ sudo apt install doxygen graphviz`
`$ pip install doxypypy`

While still in lasp dir:

`$ doxygen`

This will build the documentation. It can be read by:

`$ <YOUR-BROWSER> doc/html/index.html`

Or via docker:

`$ docker build -t lasp_ascee_nl:latest .`

## Install

For an editable install (while developing):

- `$ pip3 install --prefix=$HOME/.local -e .`

To install locally, for a fixed version:

- `$ pip3 install --prefix=$HOME/.local`

## Usage

- See examples directories for IPython notebooks.
- Please refer to the [documentation](https://lasp.ascee.nl/) for features.