About

This matlab utility can parse recording files from the Tobii Glasses 2 as stored on the SD card (no need for intervening Tobii software). Once parsed, it will display this data in a matlab GUI. Optional eye videos are also supported.

NB: do not expect fluent playback. I get a few frames a second on my 4K display, the matlab GUI renderer can't handle all this.

Tested on Matlab R2017b. Because a bunch of java hacks are used for the GUI, it is quite possible that the viewer part of this repository is not all that compatible with different matlab versions. Pull requests welcomed!

Screenshot

Usage

When running the viewer GUI, glassesViewer.m, a file picker will appear. Select the folder of a recording to view. This needs to point to a specific recording's folder. If "projects" is the project folder on the SD card, an example of a specific recording is: projects\rkamrkb\recordings\zi4xmt2

If you just wish to parse the Tobii glasses data into a matlab readable file, you can directly call ./function_library/TobiiGlassesRecordings/getTobiiDataFromGlasses.m with the same specific recording as above as the input argument.

Viewer interface

keys:

• left arrow or a key: show previous data window
• right arrow or d key: show next data window
• space bar: start/stop playback
• z: enter/exit zoom mode
• ctrl+r: reset vertical axes limits

mouse:

• can drag the time indicator (red line in data axes) with left mouse button. escape key cancels this action.
• dragging with right mouse button (or left mouse button + cnrl) moves the visible data in the window
• double-click on data axis sets time to clicked time
• using mouse scrollwheel when on data axis has two functions:

1. if holding down ctrl, the time window is zoomed along the cursor position
2. if holding down shift, the value range of the vertical axis is zoomed along the cursor position

TODOs

• have settings in an option file (XML or json? prefer latter)
• progress bar when loading in data Tobii data (not linear time but can indicate steps completed or so)
• support for viewing data from other systems (e.g. SMI glasses)
• make fancier file picker (see undocumentedmatlab example). When selecting a folder, autodetect which tracker the data comes from and sampling freq (and e.g. for SMI, notify that you must run idfconverter if have not yet done that). User can change detected system (and should file a defect)
• file picker: In case of Tobii, read those json files upon folder selection, show recording/PP name and such
• file picker: if failed (e.g. wrong folder), outline the problem areas in red

Known issues

• matlab VideoReader (at least in R2017b on Windows 10) cannot read the last few frames of some video files, when seeking to a specific time of frame, even though it can read them when just reading through the file frame by frame. This appears to occur for files where the last few frames are marked as keyframes in the mp4 stss table, even though they are not. All read frames are correct, so not a big problem.

License details

Most parts of this repository are licensed under the Creative Commons Attribution 4.0 (CC BY 4.0) license.

Acknowledgments

mp4 parsing code extracted from https://se.mathworks.com/matlabcentral/fileexchange/28028-mpeg-4-aac-lc-decoder