Audio Codes Notes¶

Installation¶

 python3.10 -m venv venv
 source venv/bin/activate
 pip install --upgrade pip
 pip install -r audio-codes-requirements.txt

On MacOS:

  brew install portaudio
  pip install pyaudio

On Linux:

  sudo apt-get install portaudio19-dev

TODO:¶

Review psychopy and sound API and possibly use PTB’s facilities in PsychoPy for precise audio placement in time: https://www.psychopy.org/download.html https://psychopy.org/api/sound/playback.html

Look at watermark in audio.

PsychoPy, Sound, PTB¶

On MacOS:¶

NOTE: PsychoPy (2024.2.3) current requirements limits/suggests to Python version 3.10.

Download and install the standalone package: PsychoPy 2024.2.3 modern (py3.10) https://github.com/psychopy/psychopy/releases/download/2024.2.3/StandalonePsychoPy-2024.2.3-macOS-py3.10.dmg

Run PsychoPy and check the sound settings that pbt is set as Audio Library.

Make sure Python 3.10 is installed and venv is explicitly created with it:

   python3.10 -m venv venv
   source venv/bin/activate
   pip install --upgrade pip
   pip install -r audio-codes-requirements.txt

NOTE: first time PsychoPy is run, it may takes a long time to setup audio download additional dependencies.

On Linux (Ubuntu 22.04):¶

Create some folder for psychopy installation and init Python 3.10 venv:

   python3.10 -m venv venv
   source venv/bin/activate

Then fetch a wxPython wheel for your platform from: https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ and download it locally to your machine. In my case it was https://extras.wxpython.org/wxPython4/extras/linux/gtk3/ubuntu-22.04/wxPython-4.2.1-cp310-cp310-linux_x86_64.whl downloaded to wxPython/wxPython-4.2.1-cp310-cp310-linux_x86_64.whl .

Install sound dependencies (1st one may fail):

   sudo apt-get install libusb-1.0-0-dev portaudio19-dev libasound2-dev
   pip install psychtoolbox

Install wxPython in venv with, e.g.:

   pip install wxPython/wxPython-4.2.1-cp310-cp310-linux_x86_64.whl

Then install psychopy:

   pip install psychopy

Run psychopy:

   psychopy

NOTE: PsychoPy PTB sound was non tested on Ubuntu 22.04, due to upgrade to 24.04.

On Linux (Ubuntu 24.04):¶

Somehow was unable to run python3.10 directly so installed it manually together with venv:

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.10
sudo apt install python3.10-venv

After this python3.10 failed to create venv so used following commands to create it:

python3.10 -m venv --without-pip venv
source venv/bin/activate
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python get-pip.py

Then installed wxPython it can take up to 1 hour to compile it (there is no pre-built wheels for Ubuntu 24.04 ATM):

sudo apt update
sudo apt install python3-dev python3-pip libgtk-3-dev
pip install wxPython

Finally installed psychopy:

pip install psychopy

Applied security fix for audio scripts user, by adding current user to audio group:

sudo usermod -a -G audio $USER

and to adjust real-time permissions by creating a file /etc/security/limits.d/99-realtime.conf

sudo vi /etc/security/limits.d/99-realtime.conf

with the following content:

@audio   -  rtprio     99
@audio   -  memlock    unlimited

Then rebooted the system.

NOTE: PsychoPy PTB still doesn’t work on Ubuntu 24.04 and script produces error, TBD:

[DEBUG] play sound with psychopy ptb
Failure: No such entity
Failure: No such entity

NeuroDebian/Singularity¶

On Linux (Ubuntu 22.04) :

Was unable to install singularity-container from neurodebian repository after multiple attempts, so finally upgraded Linux 22.04 to 24.04.

On Linux (Ubuntu 24.04) :

wget -O- http://neuro.debian.net/lists/noble.de-m.libre | sudo tee /etc/apt/sources.list.d/neurodebian.sources.list
sudo apt-key adv --recv-keys --keyserver hkps://keyserver.ubuntu.com 0xA5D32F012649A5A9

sudo apt-get update

sudo apt-get install singularity-container

singularity --version
  singularity-ce version 4.1.1

Summary¶

PyDub allows you to generate simple tones easily.
FSK modulation can be achieved using numpy and scipy to create varying frequency tones based on binary input.
Optionally DTMF encoding is implemented using predefined frequency pairs, and you can detect DTMF tones by analyzing the audio input.
Chirp SDK: Chirp.io / https://www.sonos.com/en/home https://github.com/chirp
GNU Radio - can be used to encode/modulate/demodulate. https://www.gnuradio.org/ Supports Frequency Shift Keying (FSK), Phase Shift Keying (PSK), or Amplitude Modulation (AM).
reedsolo can be used for ECC (Error Correction Codes).

Appendix: A¶

Some ffmpeg audio commands to prepare/filter files:

ffmpeg -i IMG_6454.mov -vn -ac 1 -ar 44100 -sample_fmt s16 IMG_6454.wav
ffmpeg -i IMG_6454.mov -vn -ac 1 -ar 44100 -sample_fmt s16 -t 00:00:03 IMG_6454a.wav
ffmpeg -i IMG_6454.mov -vn -ac 1 -ar 44100 -sample_fmt s16 -t 1.7 IMG_6454b.wav

ffmpeg -i IMG_6455.mov -vn -ac 1 -ar 44100 -sample_fmt s16 -ss 00:00:03 -t 00:00:02 IMG_6455_11.wav

ffmpeg -i IMG_6459.mov -vn -ac 1 -ar 44100 -sample_fmt s16 -ss 00:00:00 -t 2.3 IMG_6459_0.wav
ffmpeg -i IMG_6459_0.wav -af "bandpass=f=1780:width_type=h:w=40" IMG_6459_0_pre.wav
ffmpeg -i IMG_6459_0.wav -af "bandpass=f=5000:width_type=h:w=10" IMG_6459_0_code.wav
ffmpeg -i IMG_6459_0.wav -af "firequalizer=gain='if(between(f,995,1005),1,if(between(f,4995,5005),1,-INF))'" IMG_6459_0_code.wav

ffmpeg -i IMG_6460.mov -vn -ac 1 -ar 44100 -sample_fmt s16 -ss 2.5 -t 1.5 IMG_6460_2.wav
ffmpeg -i IMG_6460_2.wav -af "firequalizer=gain='if(between(f,995,1005),1,if(between(f,4995,5005),1,-INF))'" IMG_6460_2_f1.wav
ffmpeg -i IMG_6460_2_f1.wav -af "loudnorm=I=-1:TP=-1:LRA=11" IMG_6460_2_f2.wav

ffmpeg -i IMG_6460_2_f1.wav -af volumedetect -f null /dev/null
ffmpeg -i IMG_6460_2_f1.wav -af "volume=34.1dB" IMG_6460_2_f2.wav

ffmpeg -i IMG_6461.mov -vn -ac 1 -ar 44100 -sample_fmt s16 IMG_6461_5.wav