saraswati 0.1.0

Etymology

Saraswati is the Hindu goddess of knowledge, music, art, wisdom and learning.

Status

The software was tested successfully with Python 3.x, GStreamer 1.10.4, 1.14.4 and 1.18.4, on both Linux and macOS.

THIS IS A WORK IN PROGRESS. THERE MIGHT BE DRAGONS. YOU HAVE BEEN WARNED.

Install prerequisites

As Saraswati is based on GStreamer and, optionally, ALSA, let’s install the relevant packages.

apt-get install gstreamer1.0 gstreamer1.0-tools gstreamer1.0-alsa gstreamer1.0-plugins-base gstreamer1.0-plugins-good

apt-get install python3 python3-gst-1.0 python3-gi python3-tz

brew install gstreamer gst-python gst-libav gst-plugins-base gst-plugins-good mkvtoolnix

Configure system

Synchronize system time with NTP, this is important for appropriate timestamping:

timedatectl set-ntp true

Install Saraswati

pip install saraswati

Recording audio

saraswati record is an implementation to

• ingest audio from a GStreamer audio source element,

• run it through flacenc to encode audio with the FLAC lossless audio encoder, and

• finally store it using splitmuxsink, a GStreamer component which multiplexes incoming streams into multiple time- or size-limited files

Each audio fragment will be timestamped with the current date/time information in an ISO8601-like format, using a qualified UTC offset of +0000.

In order to learn about the command line syntax, please invoke saraswati --help or saraswati record --help.

Example output when being started at 03:35 CET:

recording_channel1_20210620T122642+0000_0000.mka
recording_channel1_20210620T122652+0000_0001.mka
recording_channel1_20210620T122702+0000_0002.mka
recording_channel1_20210620T122712+0000_0003.mka
recording_channel1_20210620T122722+0000_0004.mka

Display segment metadata information embedded into the file:

mkvinfo var/spool/recording_channel1_20210620T122642+0000_0065.mka  | grep -E 'Date|duration'
| + Date: Sun Jun 20 12:26:42 2021 UTC
|  + Default duration: 00:00:00.104489796 (9.570 frames/fields per second for a video track)

Background

This software gets developed for the “Bee Observer” (BOB) project, a joint endeavour initiated by the Cognitive neuroinformatics group at the University of Bremen and the people of the independent research and development project Hiveeyes. See also:

• hiverize.org - Vernetzt. Smart. Imkern.

• The Hiveeyes Project

• Uni Bremen und Hiveeyes werden als Citizen-Science-Projekte vom Forschungsministerium unterstützt

• System für kontinuierliche Audio-Aufzeichnung (BOB Projekt, Phase 1)

Details

The “Saraswati” program is released under the GNU AGPL license. Its source code lives on GitHub and the Python package is published to PyPI. You might also want to have a look at the documentation.

If you’d like to contribute you’re most welcome! Spend some time taking a look around, locate a bug, design issue or spelling mistake and then send us a pull request or create an issue.

Thanks in advance for your efforts, we really appreciate any help or feedback.

Code license

The code is licensed under the GNU AGPL license. See LICENSE file for details.

Have fun!