Package: opensesame-plugin-audio-low-latency
OpenSesame Plug-in: Audio Low LatencyAn OpenSesame plug-in for playing and recording audio files with low latency.Copyright, 2022, Bob Rosbag1. AboutThe main goal of this plug-in is to play and record audio with minimal and predictable latencies to achieve a high accuracy and precision. The 'PyAlsaAudio' package which uses the Linux ALSA audio system provided the best results within Python.
'PortAudio' and 'sounddevice' are cross-platform and work on both Windows as Linux.This plug-in consist of playback and recording items as well as foreground as background (multi-threaded) items.
Both playback and recording have their owninititem. These should be placed at the beginning of an experiment.Difference between foreground and background:Foregrounditems play/record until the file ends or the set duration has passed.Backgrounditems consist of a 'start', 'wait' and 'stop' item. These are fully multi-threaded. After the start of the playback/recording, the item will immediately advance to the next item. When it reaches the 'stop' or 'wait' item, it will stop the audio or wait until the file ends or duration has passed.Seven items for playback:Play Initinitialization of the playback audio device, this should be placed at the beginning of an experiment.Foreground:Playstarts the playback of audio, it will play the entire audio file or will stop after the set duration has passed before continuing to the next item in the experiment.Background:Play Startstarts the playback of audio, it will directly advance to the next item in the experiment.Play Waitwaits until the thread from 'Play Start' is finished (end of audio or surpassing the duration) before advancing to the next item in the experiment.Play Stopsends a stop signal to the 'Play Start' thread to stop immediately and checks if the thread has finished.Play Pausepauses playback of audio.Play Resumeresumes playback of audio.Seven items for recording:Record Initinitialization of the playback audio device, this should be placed at the beginning of an experiment.Foreground:Recordstarts the recording of audio, it will record for the set duration before continuing to the next item in the experiment.Background:Record Startstarts the recording of audio, it will directly advance to the next item in the experiment.Record Waitwaits until the thread from 'Record Start' is finished (surpassing the duration) before advancing to the next item in the experiment.Record Stopsends a stop signal to the 'Record Start' thread to stop immediately and checks if the thread has finished.Record Pausepauses recording of audio.Record Resumeresumes recording of audio.Timestamps can be found in the log file by the name: time_stimulus_onset_[item_name]Known bugs:Recording with the PyAudio module does not seem to work at the moment2. LICENSEThe Audio Low Latency plug-in is distributed under the terms of the GNU General Public License 3.
The full license should be included in the file COPYING, or can be obtained fromhttp://www.gnu.org/licenses/gpl.txtThis plug-in contains works of others. Icons are derivatives of the Faience icon theme, Faenza icon theme and Papirus icon theme.3. DocumentationInstallation instructions and documentation on OpenSesame are available on the documentation website:http://osdoc.cogsci.nl/